The acromioclavicular ligament shows an early and dynamic healing response following acute traumatic rupture.

PURPOSE: Symptomatic horizontal instability is clinically relevant following acute acromioclavicular joint dislocations. However, the intrinsic healing response is poorly understood. The present study sought to investigate time-dependent healing responses of the human acromioclavicular ligament following acute traumatic rupture. METHODS: Biopsies of the acromioclavicular ligament were obtained from patients undergoing surgical treatment for acute acromioclavicular joint dislocations. Specimens were stratified by time between trauma and surgery: group 1, 0-7 days (n = 5); group 2, 8-14 days (n = 6); and group 3, 15-21 days (n = 4). Time-dependent changes in cellularity, collagen (type 1 and 3) concentration, and histomorphological appearance were evaluated for the rupture and intact zone of the acromioclavicular ligament. RESULTS: Group 1 was characterized by cellular activation and early inflammatory response. The rupture zone exhibited a significantly higher count of CD68-positive cells than the intact zone (15.2 vs 7.4; P ≤ 0.05). Consistently, synovialization of the rupture end was observed. Within the second week, the rupture zone was subject to proliferation showing more fibroblast-like cells than the intact zone (66.8 vs 43.8; P ≤ 0.05) and a peak of collagen type 3 expression (group 1: 2.2 ± 0.38, group 2: 3.2 ± 0.18, group 3: 2.8 ± 0.57; P ≤ 0.05). Signs of consolidation and early remodeling were seen in the third week. CONCLUSIONS: The acromioclavicular ligament exhibits early and dynamic healing responses following acute traumatic rupture. Our histological findings suggest that surgical treatment of acute ACJ dislocations should be performed as early as possible within a timeframe of 1 week after trauma to exploit the utmost biological healing potential. Prospective clinical studies are warranted to investigate whether early surgical treatment of ACJ dislocations translates into clinical benefits.

Osteoarthritic changes rather than age predict outcome following arthroscopic treatment of femoroacetabular impingement in middle-aged patients.

BACKGROUND: Our purpose was to evaluate outcome following arthroscopic treatment of femoroacetabular impingement (FAI) in middle-aged patients and to define risk factors for conversion to total hip arthroplasty (THA). METHODS: This was a retrospective case series of 79 consecutive patients (40 to 65 years) undergoing arthroscopic treatment of FAI (follow-up ≥12 months). Outcome at follow-up was assessed using Hip outcome score (HOS). Alpha angle, Kellgren Lawrence grade (K-L grade), joint space width (JS), lateral center edge (LCE) angle, caput-collum-diaphysis (CCD) angle and acetabular index (AI) were analysed retrospectively. THA group and Non-THA group were compared. RESULTS: Seventy-nine patients (mean age 48.6 years, mean follow-up 32 months) were included. 18 patients (22.8 %) were converted to THA. Mean HOS score in the Non-THA group at time point of follow-up was 80.2. Non-THA group and THA group showed no significant differences for mean age (48.2 years vs. 49.9 years, p = 0.278), alpha angel (p = 0.541), LCE (p = 0.294), CCD (p = 0.101) and AI (p = 0.661) in contrast to differences for JS (p = <0.001) and K-L grade (p = <0.001). Risk of conversion to THA was higher for patients with K-L grade 3 (p = 0.003) or joint space less or equal 2 mm (p = 0.001). CONCLUSIONS: One fifth of the middle-aged patients required early conversion to THA. Advanced JS narrowing and K-L grade rather than age alone can be considered as risk factor for conversion to THA.

Emergency radiological examination of the externally stabilized pelvis--there is a catch to it: lessons learned from two cases with symphyseal disruption despite initial inconspicuous computed tomography.

BACKGROUND: Preclinical and early clinical external pelvic stabilization using commercially available devices has become common in trauma patient care. Thus, in the emergency department an increasing number of patients will undergo radiographic evaluation of the externally stabilized pelvis to exclude injuries. While reports exist where injuries to the pelvis were elusive to radiological examination due to the pelvic immobilization we elaborate on an algorithm to remove an external pelvic stabilizing device, prevent delayed diagnosis of pelvic disruption and thus increase patient safety. CASE PRESENTATION: We report on two patients with external pelvic stabilization presenting with an inconspicuous pubic symphysis on initial pelvic computed tomography scans. The first patient was an otherwise healthy 51-year old male being run over by his own car. He received external pelvic stabilization in the emergency department. The second patient was a 36-year old male falling from a ladder. In this patient external pelvic stabilization was performed at the scene. In the first patient no pelvic injury was obvious on computed tomography. In the second patient pelvic fractures were diagnosed, yet the presentation of the pubic symphysis appeared normal. Nevertheless, complete symphyseal disruption was diagnosed in both of them upon removal of the external pelvic stabilization and consequently required internal fixation. CONCLUSION: Based on our experience we propose an algorithm to "clear the initially immobilized pelvis" in an effort to minimize the risk of missing a serious pelvic injury and increase patient safety. This is of significant importance to orthopedic trauma surgeons and emergency physicians taking care of injured patients.

Open fixation of acute anterior glenoid rim fractures with bioresorbable pins: analysis of clinical and radiological outcome.

INTRODUCTION: The purpose of this study was a detailed analysis of clinical and radiological results following open fixation of acute-traumatic, displaced anterior glenoid rim fractures with bioresorbable pins. MATERIALS AND METHODS: This retrospective study included 17 patients with glenoid defect sizes ≥20 %, as directly measured in preoperative sagittal en face CT. The mean glenoid defect size was 25.3 % (20-35, SD 4.7). Two or three polylactid pins were used for fixation. Mean age of patients at the time of surgery was 50.1 years (27-71). The mean follow-up period was 6.2 years (2.0-11.1). Follow-up included comprehensive objective and subjective evaluation of shoulder function as well as standard radiographs. RESULTS: The majority of 15/17 patients obtained good or excellent clinical results according to the absolute and normalized Constant score, the Rowe score, the Oxford shoulder score, the simple shoulder test, the shoulder pain and disability index and the subjective shoulder value. Quality of life (SF-36) showed reference values. Mean or subitem values of all outcome measures did not differ from the contralateral, uninjured side. Radiographically, all fractures healed without secondary dislocation. Radiological signs of glenohumeral arthritis developed in two patients and progressed in two other patients. There were no implant-related complications. No patient experienced glenohumeral instability or had to undergo revision surgery. CONCLUSIONS: Bioresorbable pin fixation is a feasible and safe method of osteosynthesis for anterior glenoid rim fractures up to a glenoid defect size of about 35 % and enables immediate active range of motion. Good or excellent clinical outcome can be expected and glenohumeral stability is reliably restored. The most common mid- and long-term complication is occurrence or progression of osteoarthritis. The major benefits of bioresorbable pin fixation are redundancy of implant removal, minimal risk of implant-related complications and early functional rehabilitation.

Internal fixation of dorsally comminuted fractures of the distal part of the radius: a biomechanical analysis of volar plate and intramedullary nail fracture stability.

INTRODUCTION: The purpose of the present study was to carry out biomechanical testing of "new generation" volar plates and an intramedullary nail. METHODS: Four volar locking plates (Column Plate, VariAx distal radius, 2.4 mm-LCP and 3.5 mm-LCP) and the intramedullary nail, Targon-DR, were implanted in biomechanically validated artificial bones after simulation of a wedge osteotomy with total transection of the volar cortex to mimic a type 23 A3-fracture according to the AO-classification. Axial load (250 Newton [N]) and volar and dorsal bending loads (both 50 N) were applied. Axial load was increased to fixation failure. Gap motion was measured three-dimensionally directly at the fracture gap. The 3.5 mm-LCP was used for comparison as it currently represents an established locking implant that has been well tested biomechanically. RESULTS: In this experimental setting, the 2.4 mm-LCP showed the lowest resistance under all three loading modi and, consequently, the highest level of motion at the osteotomy gap in comparison to all other implants (p < 0.05). Under axial loading, there were no significant differences between the other four implants. Under dorsal bending, the Targon-DR-nail and the VariAx-plate showed less gap displacement in comparison to the 3.5 mm-LCP (p < 0.05). Under volar bending, only the Targon-nail showed greater resistance than the 3.5 mm-LCP (p < 0.05) with no other significant differences between the Column Plate, the VariAx and the 3.5 mm-LCP. CONCLUSION: In this experimental setting, all "new generation" implants for distal radius fractures with the exception of the 2.4 mm-LCP showed identical or higher stability compared to the 3.5 mm-LCP. The 2.4 mm-LCP showed the lowest resistance and this must be taken into consideration when planning postoperative functional therapy.

Early surgery-related complications after anteroposterior stabilization of vertebral body fractures in the thoracolumbar region.

BACKGROUND: The complication rate after trauma-associated spine surgery remains unknown because of the rarity of this injury and the polymorphism of treatment methods. We report the complication rates recorded at one center after treatment of unstable vertebral body fractures according to a single, uniform procedure. The aim of this analysis was to identify the typical complications associated with this surgical procedure and, consequently, to contribute to critical deliberations on the introduction of technical innovations such as navigation, intraoperative three-dimensional imaging, and neuromonitoring. METHODS: Perioperative complications related to surgery of 208 consecutive patients, operated on for unstable vertebral body fractures were analyzed. First, stabilization was performed through an open, posterior, nonnavigated approach. This was followed, in all patients, by reconstruction of the anterior column form with a tricortical iliac crest graft during a second operation. RESULTS: In regard to posterior stabilization, at least one pedicle screw in six patients (3%) was placed incorrectly; furthermore, there were five patients with general complications, all of which required revision surgery. After anterior spondylodesis, there were also nine general complications and five neurological complications, one of them in a patient with persistent paraplegia. At the graft donor site, three patients experienced an avulsion fracture of the anterosuperior iliac crest. Overall, at least one complication occurred in 13% of patients (confidence interval 0.08-0.18). CONCLUSIONS: With regard to early complications, two-stage anteroposterior stabilization of unstable spinal fractures of the thoracolumbar spine is a reliable procedure.

Clinical and radiological outcomes after stabilisation of complex intra-articular fractures of the distal radius with the volar 2.4 mm LCP.

AIM: The purpose of the present study is to evaluate the results of the treatment of intra-articular fractures with the volar 2.4 mm LCP with regard to loss of reduction, clinical outcome and complications. PATIENTS: Patients treated with a volar 2.4 mm LCP following a complex intra-articular distal radius fracture were assessed by clinical and radiological examination of both wrists, the Disability of Arm, Shoulder and Hand (DASH) outcome instrument, Martini score and the pain Visual Analogue Scale score. Forty patients (40 fractures: 5 type C1, 11 type C2, and 24 type C3 according to AO/OTA classification) were followed at a mean 18 months from the injury. RESULTS: Of the initial 40 fractures, 4 fractures required surgical revision (1 because of loss of reduction, 2 due to fracture incongruity as seen on the postoperative computer tomogram and 1 case of screw displacement in the radial shaft). Radiographs in the immediate postoperative period showed a radial inclination of 22.1 degrees, volar tilt of 7.2 degrees, and ulnar deviation of 0.2 mm (means). At follow-up examination, radial inclination was 23.8 degrees, volar tilt was 6.2 degrees and ulnar deviation was 0.9 mm (means). Average final wrist range of motion was significantly (p < 0.05) decreased in comparison to contralateral wrist. Average DASH and Martini scores were 18 and 27, respectively, with no significant differences between C1-, C2- and C3-type fractures. Patients who underwent a surgical revision had poorer Martini score. Complications were an EPL tendon rupture, a tendon irritation and a complex regional pain syndrome in a patient who underwent revision. CONCLUSION: The treatment of complex intra-articular distal radius fractures with the volar 2.4 mm LCP provides sufficient fixation to prevent clinically significant loss of articular reduction, acceptable patient outcomes and minimal soft tissue complications.

Plate fixation of periprosthetic femur fractures: What happens to the cement mantle?

Osteosynthesis of periprosthetic femur fractures by screw fixation around the implanted prosthetic stem is currently regarded as the biomechanically superior option compared with cerclage. The aim of this biomechanical study was damage analysis of the cement mantle after revision screw insertion. A prosthetic stem (Bicontact) was implanted in 20 cadaveric femora in cemented technique. A locking compression plate (Synthes) was then applied to the lateral femur at the level of the prosthetic stem. The method of plate fixation to the femur was assigned randomly to three groups: bicortical non-locking screws, monocortical locking screws, and bicortical locking screws. This was followed by applying a fluctuating axial load (2100 N, 0.5 Hz) for 20,000 cycles. After testing, macroscopic and microscopic evaluations of the cement mantle were conducted. Cracks formed in the cement mantle in 14% of the 80 screw holes. The type of screw (bicortical or monocortical; locking or non-locking) had no significant effect on the number of cracks (p = 0.52). The relationship between manifestation of crack damage and cement mantle thickness was not significant (p = 0.36), whereas the relationship between crack formation and screw position was significant (p = 0.019). Those screws whose circumference was only partially within the cement mantle yielded a significantly lower number of cracks compared with screws positioned completely within the cement mantle or even touching the prosthetic stem. In order to reduce the incidence of crack formation in the cement mantle during plate osteosynthesis of periprosthetic femur fractures, the screws should not be either placed within the cement mantle or make direct contact with the stem.

Radiological evaluation of the posterior pelvic ring in paediatric patients: Results of a retrospective study developing age- and gender-related non-osseous baseline characteristics in paediatric pelvic computed tomography - References for suspected sacroiliac joint injury.

INTRODUCTION: The prevalence of paediatric pelvic injury is low, yet they are often indicative of accompanying injuries, and an instable pelvis at presentation is related to long-term poor outcome. Judging diastasis of the sacroiliac joint in paediatric pelvic computed tomography is challenging, as information on their normal appearance is scarce. We therefore sought to generate age- and gender-related standard width measurements of the sacroiliac joint in children for comparison. PATIENTS AND METHODS: A total of 427 pelvic computed tomography scans in paediatric patients (<18 years old) were retrospectively evaluated. After applying exclusion criteria, 350 scans remained for measurements. Taking a standard approach we measured the sacroiliac joint width bilaterally in axial and coronal planes. RESULTS: We illustrate age- and gender-related measurements of the sacroiliac joint width as a designated continuous 3rd, 15th, 50th, 85th and 97th centile graph, respectively. Means and standard deviations in the joint width are reported for four age groups. There are distinct changes in the sacroiliac joint's appearance during growth. In general, male children exhibit broader sacroiliac joints than females at the same age, although this difference is significant only in the 11 to 15-year-old age group. CONCLUSION: The sacroiliac joint width in children as measured in coronal and axial CT scans differs in association with age and gender. When the sacroiliac joint width is broader than the 97th centile published in our study, we strongly encourage considering a sacroiliac joint injury.

Sliding of the load carrier in third-generation intramedullary nails for proximal femur fractures: an in vitro mechanical comparison study.

Dynamic osteosynthesis of proximal femur fractures facilitates compression at the fracture site through distal glide of the femoral head load carrier in the intramedullary nail. Modern implants are currently designed according to diverse gliding principles. The aim of this study was to compare the sliding mechanisms of different types of nails. As in other similar mechanical studies the load patterns occurring around the femoral head load carrier and the intramedullary nail under full load were simulated for three different types of intramedullary nail - PFNA, Targon PFT and Trigen Intertan. The load necessary to trigger distal displacement of the femoral head implant in the nail was determined. The lengths of the load carriers were varied. For the three lengths of load carrier, mechanical testing showed that the Targon PFT started to slide at a significantly lower load compared to the other two implants. Comparison of the PFNA and Trigen Intertan in terms of load to dynamization for 77 mm carriers revealed a significantly lower load for the PFNA. Slide efficacy for the PFNA and the Trigen Intertan was found to improve as the length of the blade/screw was shortened. The dynamization properties of the Targon PFT with its cylindrical sliding mechanism, similar to the DHS, were far better compared to the PFNA and the Trigen Intertan that have more complex sliding actions. Since theoretical considerations indicate that a less efficient gliding action leads to a higher complication rate, implants of the next generation should be optimized in this regard.