Consensus for management of sacral fractures: from the diagnosis to the treatment, with a focus on the role of decompression in sacral fractures.

BACKGROUND: There is no evidence in the current literature about the best treatment option in sacral fracture with or without neurological impairment. MATERIALS AND METHODS: The Italian Pelvic Trauma Association (A.I.P.) decided to organize a consensus to define the best treatment for traumatic and insufficiency fractures according to neurological impairment. RESULTS: Consensus has been reached for the following statements: When complete neurological examination cannot be performed, pelvic X-rays, CT scan, hip and pelvis MRI, lumbosacral MRI, and lower extremities evoked potentials are useful. Lower extremities EMG should not be used in an acute setting; a patient with cauda equina syndrome associated with a sacral fracture represents an absolute indication for sacral reduction and the correct timing for reduction is "as early as possible". An isolated and incomplete radicular neurological deficit of the lower limbs does not represent an indication for laminectomy after reduction in the case of a displaced sacral fracture in a high-energy trauma, while a worsening and progressive radicular neurological deficit represents an indication. In the case of a displaced sacral fracture and neurological deficit with imaging showing no evidence of nerve root compression, a laminectomy after reduction is not indicated. In a patient who was not initially investigated from a neurological point of view, if a clinical investigation conducted after 72 h identifies a neurological deficit in the presence of a displaced sacral fracture with nerve compression on MRI, a laminectomy after reduction may be indicated. In the case of an indication to perform a sacral decompression, a first attempt with closed reduction through external manoeuvres is not mandatory. Transcondylar traction does not represent a valid method for performing a closed decompression. Following a sacral decompression, a sacral fixation (e.g. sacroiliac screw, triangular osteosynthesis, lumbopelvic fixation) should be performed. An isolated and complete radicular neurological deficit of the lower limbs represents an indication for laminectomy after reduction in the case of a displaced sacral fracture in a low-energy trauma associated with imaging suggestive of root compression. An isolated and incomplete radicular neurological deficit of the lower limbs does not represent an absolute indication. A worsening and progressive radicular neurological deficit of the lower limbs represents an indication for laminectomy after reduction in the case of a displaced sacral fracture in a low-energy trauma associated with imaging suggestive of root compression. In the case of a displaced sacral fracture and neurological deficit in a low-energy trauma, sacral decompression followed by surgical fixation is indicated. CONCLUSIONS: This consensus collects expert opinion about this topic and may guide the surgeon in choosing the best treatment for these patients. LEVEL OF EVIDENCE: IV. TRIAL REGISTRATION: not applicable (consensus paper).

Salvaging Pull-Out Strength in a Previously Stripped Screw Site: A Comparison of Three Rescue Techniques.

Screw stripping during bone fixation is a common occurrence during operations that results in decreased holding capacity and bone healing. We aimed to evaluate the rescue of the stripped screw site using screws of different dimensions. Five screw configurations were tested on cadaveric specimens for pull-out strength (POS). The configurations included a control screw tightened without stripping, a configuration voluntarily stripped and left in place, and three more configurations in which the stripped screws were replaced by a different screw with either increased overall length, diameter, or thread length. Each configuration was tested five times, with each screw tested once. The POS of the control screw, measured to be 153.6 ± 27 N, was higher than the POS measured after stripping and leaving the screw in place (57.1 ± 18 N, p = 0.001). The replacement of the stripped screw resulted in a POS of 158.4 ± 64 N for the screw of larger diameter, while the screws of the same diameter but increased length or those with extended thread length yielded POS values of 138.4 ± 42 and 185.7 ± 48 N, respectively. Screw stripping is a frequent intraoperative complication that, according to our findings, cannot be addressed by leaving the screw in place. The holding capacity of a stripped screw implanted in cancellous bone can successfully be restored with a different screw of either larger diameter, longer length, or extended thread length.

The effect of viscosupplementation on early-stage knee osteoarthritis: Clinical evaluation and assessment of cartilage in vivo with 7 T MRI.

INTRODUCTION: Viscosupplementation is a well-known strategy for managing early stages knee Osteoarthritis. However, despite its effectiveness in reducing symptoms, it has not yet been found to have an effect on joint cartilage. The aim of this study is to evaluate the clinical efficacy of a new product with gel-like behaviour and its in vivo effects on joint cartilage. METHODS: 20 patients were treated by 2 consecutive injections of hyaluronan derivative Hymovis® at one-week interval. Clinical evaluation was performed before the treatment and at each time point during the follow-up using WOMAC and VAS. A 7 T magnet was used for cartilage evaluation at each MRI time point: T2 Relaxation Time (RT), T2∗ RT and cartilage parameters were evaluated before the first injection, after 45 days and at 6 months follow-up. Statistical analysis was obtained for each reported data. RESULTS: We report significantly reduction in symptoms with an increase in knee and global activity functions. The T2 RT for lateral tibial compartment and T2∗ RT for Patello-Femoral compartment significantly decreased. A T2 RT reduction was observed in all knee compartments except for the medial tibial one, while a T2∗ RT reduction was observed in all knee compartments. We report an increase in cartilage volume and thickness in most of patients with a reduction of cartilage defects in 9 patients, but we didn't find MRI signals clearly referable to cartilage regeneration. CONCLUSIONS: MRI results have confirmed the possibility to employ 7T magnets to evaluate early changes in cartilage structure in vivo. HA VS has provided good clinical outcomes and an improvement in the global assessment of the knee joint, but it doesn't seem to significantly modify the cartilage over the time.

Magnetic Resonance Imaging of the Knee in the Presence of Bridging External Fixation: A Comparative Experimental Evaluation of Four External Fixators, Including Dolphix®.

Performing MR investigation on patients instrumented with external fixators is still controversial. The aim of this study is to evaluate the quality of MR imaging of the knee structures in the presence of bridging external fixators. Different cadaveric lower limbs were instrumented with the MR-conditional external fixators Hofmann III (Stryker, Kalamazoo, MI, USA), Large external Fixator (DePuy Synthes, Raynham, MA, USA), XtraFix (Zymmer, Warsaw, IN, USA) and a newer implant of Ketron Peek CA30 and ERGAL 7075 pins, Dolphix®, (Citieffe, Bologna, Italy). The specimens were MR scanned before and after the instrumentation. The images were subjectively judged by a pool of blinded radiologists and then quantitatively evaluated calculating signal intensity, signal to noise and contrast to noise in the five regions of interest. The area of distortion due to the presence of metallic pins was calculated. All the images were considered equally useful for diagnosis with no differences between devices (p > 0.05). Only few differences in the quantification of images have been detected between groups while the presence of metallic components was the main limit of the procedure. The mean length of the radius of the area of distortion of the pins were 53.17 ± 8.19 mm, 45.07 ± 4.33 mm, 17 ± 5.4 mm and 37.12 ± 10.17 mm per pins provided by Zimmer, Synthes, Citieffe and Stryker, respectively (p = 0.041). The implant of Ketron Peek CA30 and ERGAL 7075 pins showed the smallest distortion area.

Proposal of a New Dynamic Distraction Device to Treat Complex Periarticular Fractures of the Metacarpophalangeal Joint of Long Finger.

Background: Complex periarticular fractures of the metacarpophalangeal joint (MCPJ) are often challenging to treat. Conservative and operative treatments are often burdened with stiffness, loss of function, and poor clinical outcome. These phenomena could be a direct consequence of long period of immobilization. To promote a short time of immobilization and a quick return to daily activities, it is mandatory to stabilize the fracture maintaining the active range of motion (AROM) of the ray. A simple solution is to reduce the fragments by means of dynamic ligamentotaxis. The authors propose a new dynamic distraction device (DDD) for the MCPJ. Methods: The DDD for the MCPJ was made of Kirschner wires bent and connected to counteract dislocation forces and to allow mobilization of the joint. The DDD was tested on a cadaver model under a simulated load in physiological conditions, and also in metacarpal and proximal phalanx (P1) fracture patterns. The effectiveness of the device was evaluated under fluoroscopy. Results: The data showed that DDD is able to achieve fracture reduction through ligamentotaxis and primary fragments stability and to avoid secondary dislocation during AROM of complex periarticular fractures of the MCPJ. Conclusions: The frame could be an alternative option to treat periarticular fractures of the MCPJ. The DDD implant has several advantages: It is time efficient because assembly and application take only few minutes. Furthermore, it is very versatile; indeed, it can be used in all metacarpal and phalanx bones, even in the central rays.

Screw insertion torque as parameter to judge the fixation. Assessment of torque and pull-out strength in different bone densities and screw-pitches.

BACKGROUND: Pull-out strength is a critical parameter to judge screw fixation in orthopaedic implants. However, the insertion torque is the main feeling in the hand of a surgeon relating to the strength of synthesis. The correlation between pull-out strength and torque is not completely understood. This creates uncertainty about the key-question: Should the torque be considered a valid parameter to judge the quality of fixation? METHODS: Using the ASTM F543 as reference, three screws differing only in pitch (1.5, 2.1, 2.8 mm pitches) were tested in three foam-block densities (10, 15, and 20 pcf). The correlation was investigated by assessing the role of density and screw geometry. FINDINGS: Torque was related to pull-out strength in all configurations (R = 0.979, P = 0.000). No difference in pull-out strength was found when screws were tightened to a range of 71.6%, SD = 7.6, of torque to fail (P > 0.05). Torque and pull-out strength were stratified according to density that influenced the two parameters up to 524% (P < 0.000). Pitch determined pull-out strength up to 33% (P < 0.000) while the 2.1 mm screw pitch showed the highest pull-out strength and torque in all configurations. INTERPRETATION: Insertion torque was demonstrated to be a valid parameter to judge the quality of bone under fixation and therefore, the strength of the synthesis. Surgeons should not tighten the screws to values approaching torque to fail to obtain the highest pull-out strength. Density was the main factor influencing pull-out strength and torque. Pitch is another parameter deciding screw holding capacity.

Pyruvate and lactate as local prognostic biomarkers of patient outcome after achilles tendon rupture.

BACKGROUND: Acute Achilles tendon rupture (ATR) is a frequently disabling injury, which exhibits unclear variability in long-term functional and patient-reported outcomes. Biomarkers from early healing, which have been shown to be prognostic of long-term outcome would facilitate the development of improved treatment methods. HYPOTHESIS/PURPOSE: The aim of this study was to assess essential metabolites pyruvate and its product lactate, as early biomarkers in relation to long-term functional- and patient-reported outcome after ATR. STUDY DESIGN: Prospective cohort study. METHODS: A total of 124 patients (103 men, 21 women; mean age 40 ± 7 years) with ATR, treated with uniform anesthetic and surgical technique, were prospectively assessed. At two weeks post-injury pyruvate and lactate concentrations were assessed in both the injured and uninjured limbs using microdialysis followed by enzymatic quantification. The ratios of the concentration in the injured versus uninjured limb of pyruvate (pyruvate-r) and lactate (lactate-r) were calculated as well as the lactate/pyruvate ratios (L/P-r). At 12 months, patient-reported outcome was examined using self-reported questionnaires; Achilles tendon Total Rupture Score (ATRS), Foot and Ankle Outcome Score (FAOS), and physical activity score. At 12 months, functional outcome was studied using the validated heel-rise test. RESULTS: Elevated pyruvate-r, at two weeks, was significantly associated with total ATRS (R = 0.254, P = 0.028), less loss in physical activity (R = 0.241, P = 0.039), less experience of pain in FAOS (R = 0.275, P = 0.032), and a higher number of heel-rise repetitions on injured side (R = 0.230, P = 0.040) at 12 months. Increased lactate-r was related with less strength limitations in the calf (R = 0.283, P = 0.011), while the elevated lactate-pyruvate ratio, notably, was related to more limitations in walking on uneven surface (R = -0,243, P = 0.027). The findings were verified by multiple linear regression taking confounding factors into consideration. CONCLUSION: This study established that the metabolite pyruvate is a good potential biomarker, prognostic of patient outcome at the one-year follow-up after ATR surgery. These novel findings suggest that local biomarkers could be developed at an early-stage screen for new ATR treatments.

Traumatic anterior dislocation of a prosthetic knee, from trauma to delayed onset of vascular injury.

Anterior dislocation of a prosthetic knee is a rare event. Only few episodes have been described in the past and have never been linked with neurovascular injury. This could lead orthopaedic surgeons to focus on the implant instability factors and underrate other complications. The authors report a case of a patient who experienced popliteal artery dissection 80 hours after traumatic anterior knee dislocation of a previously well-functioning total knee arthroplasty. Given that there is a lack of clinical cases that have established guidelines for management of this problem, the authors have focused on the importance of performing computed tomography angiography in the management of an anterior traumatic knee dislocation of a prosthetic knee.