Screw Osteosynthesis Research Articles

Biomechanical stability of sacroiliac screw osteosynthesis with and without cement augmentation

BackgroundPercutaneous sacroiliac (SI) screw fixation is the standard operative treatment of traumatic disruptions to the posterior pelvic ring. The technique offers good outcomes and early postoperative mobilization, which is vital in elderly patients with fragility fractures of the pelvis. While a double-screw technique has been shown to provide optimal biomechanical stability compared to a single-screw construct, anatomic variations and patient-specific characteristics may prevent the safe insertion of two SI screws. We aimed to determine whether cement augmentation of a single SI screw would provide biomechanical stability comparable to that of the double-screw technique. MethodsThree sacroiliac screw osteosynthesis configurations were tested on 10 human cadaveric pelvis specimens: a single cannulated screw; two cannulated screws; and a single, cement-augmented cannulated screw. Displacement and stiffness of the anterior and posterior pelvic ring after fixation with each technique were measured under axial load. Results where compared using linear regression and paired t-tests. ResultsA single uncemented screw offered significantly worse stability in the anterior pelvis compared to a double-screw technique (P < 0.05) and to a single cement-augmented screw technique (P < 0.05). There was no significant difference in anterior pelvic ring stability between the single cement-augmented screw technique and the double-screw technique (P > 0.05). There was no significant difference in the stability of the posterior pelvic ring between the three techniques (P > 0.05). ConclusionsA single cement-augmented cannulated sacroiliac screw provides biomechanical stability similar to that of a non-augmented double-screw technique in the treatment of posterior pelvic ring fractures.

Intramedullary screw fixation for metacarpal shaft fractures: a biomechanical human cadaver study.

Intramedullary cannulated compression screws have been introduced for the fixation of unstable metacarpal fractures. In the present study, this technique was compared with dorsal compression plating to evaluate its biomechanical performance in stabilizing metacarpal shaft fractures. In a first set of experiments, the biomechanical characteristics of the screws were analysed in an artificial bone model. In subsequent experiments, midshaft osteotomies were performed in human cadaver metacarpals, followed by plating or intramedullary screw osteosynthesis. The metacarpals were tested to failure in cantilever bending, following a stepwise increasing cyclic loading protocol. We found a significantly lower load at failure and a significantly lower number of cycles to failure in the intramedullary screw group, but both methods offered sufficient stability under these loads. With reference to published loads on the metacarpals during use of the hand, we conclude that intramedullary osteosynthesis yields sufficient strength and stiffness for early active motion. A difference in its fixation stability is noted compared with plate fixation, which may not be clinically relevant.

Influence of reduction accuracy in lateral tibial plateau fractures on intra-articular friction \u2013 a biomechanical study

BackgroundLateral tibial split fractures (LTSF) usually require surgical therapy with screw or plate osteosynthesis. Excellent anatomical reduction of the fracture is thereby essential to avoid post-traumatic osteoarthritis. In clinical practice, a gap and step of 2 mm have been propagated as maximum tolerable limit. To date, biomechanical studies regarding tibial fractures have been limited to pressure measurement, but the relationship between dissipated energy (DE) as a friction parameter and reduction accuracy in LTSF has not been investigated. In past experiments, we developed a new method to measure DE in ovine knee joints. To determine weather non-anatomical fracture reduction with lateral gap or vertical step condition leads to relevant changes in DE in the human knee joint, we tested the applicability of the new method on human LTSFs and investigated whether the current limit of 2 mm gap and step is durable from a biomechanical point of view.MethodsSeven right human, native knee joint specimens were cyclically moved under 400 N axial load using a robotic system. During the cyclic motion, the flexion angle and the respective torque were recorded and the DE was calculated. First, DE was measured after an anterolateral approach had been performed (condition “native”). Then a LTSF was set with a chisel, reduced anatomically, fixed with two set screws and DE was measured (“even”). DE of further reductions was then measured with gaps of 1 mm and 2 mm, and a 2 mm step down or a 2 mm step up was measured.ResultsWe successfully established a measurement protocol for DE in human knee joints with LTSF. While gaps led to small though statistically significant increase (1 mm gap:ΔDE compared with native = 0.030 J/cycle, (+ 21%), p = 0.02; 2 mm gap:ΔDE = 0.032 J/cycle, (+ 22%), p = 0.009), this increase almost doubled when reducing in a step-down condition (ΔDE = 0.058 J/cycle, (+ 56%), p = 0.042) and even tripled in the step-up condition (ΔDE = 0.097 J/cycle, (+ 94%), p = 0.004).ConclusionsBased on our biomechanical findings, we suggest avoiding step conditions in the daily work in the operating theatre. Gap conditions can be handled a bit more generously.

Minimal-invasive stabilization of anterior pelvic ring fractures with retrograde transpubic screws

BackgroundIn the vast majority of patients with pelvic ring lesions, there is a combination of fractures of the posterior and anterior pelvic ring. Anterior fractures are painful and contribute to loss of stability of the pelvic ring. For these reasons, stabilization of pubic rami fractures is recommended together with posterior pelvic ring fixation. Retrograde transpubic screw osteosynthesis enjoys increasing acceptance due to its minimal invasive technique and adequate stability. Patients and methodsWe retrospectively reviewed the results of 158 retrograde transpubic screw osteosyntheses in 128 patients with pelvic ring lesions including a pubic ramus fracture. Sixty-three patients suffered a high-energy injury, 65 a fragility fracture of the pelvis. ResultsOne hundred and forty-six screws (92.4%) were inserted through a percutaneous procedure. There were no vascular, neurological or urological complications. Fifty-nine screws (39%) yielded an excellent reduction with less than one cortical width of displacement. Slight secondary displacement was seen in 33 of these fractures (55.9%). Early surgical complications were seen in 16 screws (10.1%): suboptimal pathway in 10, local hematoma in 4 and local infection in 3. Early revision surgery was done in 7 screws (4.4%). Median follow-up was 27.6 weeks, 83 screws (52.5%) had a follow-up of more than 6 months. During follow-up, 7.6% of screws loosened. Operative revision was performed in 13%. 75 fractures (90.3%) with a follow-up of ≥ 6 months showed radiographic evidence of healing. There was no difference in the healing rate of high-energy and fragility fractures. Nonunion rate was not dependent on the quality of primary reduction, secondary displacement, or screw loosening. Infection (p 0.001) and surgery ≥ 6 months after trauma (p 0.02) more often led to nonunion. ConclusionRetrograde transpubic screw osteosynthesis is a reliable method for splinting pubic rami fractures in high and low energy pelvic trauma. Although a slight secondary fracture displacement is seen in most cases, it does not affect fracture healing. Retrograde transpubic screw is a adequate minimal-invasive osteosynthesis to stabilize the anterior pelvic ring, especially in fragility fracture of the pelvis. Delayed operation (> 6 months) and infection show higher rate of nonunion.

Tape suture for stabilization of incomplete posterior pelvic ring fractures\u2014biomechanical analysis of a new minimally invasive treatment for incomplete lateral compression pelvic ring fractures

BackgroundIncomplete lateral compression fractures (including AO Type B2.1) are among the most common pelvic ring injuries. Although the treatment of choice remains controversial, sacroiliac (SI) screws are commonly used for the operative treatment of incomplete lateral compression fractures of the pelvic ring. However, the disadvantages of SI screws include the risk of nerve root or blood vessel injury. Recently, tape sutures have been found useful as stabilizing material for the treatment of injuries of the syndesmosis, the rotator cuff and knee ligaments. In this current study, we aimed to test the biomechanical feasibility of tape sutures to stabilize the pelvis in the setting of AO Type B2.1 injury.MethodsSix human cadaveric pelvises underwent cyclic loading to compare the biomechanical stability of different osteosynthesis methods in a B2.1 fracture model. The methods tested in this experiment were a FiberTape® suture and the currently established SI screw. A 3D ultrasound tracking system was used to measure fracture fragment motion. Linear regression was used to model displacement and stiffness at the posterior and anterior pelvic ring.ResultsAt the posterior fracture site, the FiberTape® demonstrated similar displacement (2.2 ± 0.8 mm) and stiffness (52.2 ± 18.0 N/mm) compared to the sacroiliac screw (displacement 2.1 ± 0.6 mm, P > 0.999; stiffness 50.8 ± 13.0 N/mm, P > 0.999).Considering the anterior fracture site, the FiberTape® again demonstrated similar displacement (3.8 ± 1.3 mm) and stiffness (29.5 ± 9.0 N/mm) compared to the sacroiliac screw (displacement 2.9 ± 0.8 mm, P = 0.2196; stiffness 37.5 ± 11.5 N/mm, P = 0.0711).ConclusionThe newly presented osteosynthesis, the FiberTape®, shows promising results for the stabilization of the posterior pelvic ring in AO Type B2.1 lateral compression fractures compared to a sacroiliac screw osteosynthesis based on its minimal-invasiveness and the statistically similar biomechanical properties.

Progress of minimally invasive treatment about fragility fractures of pelvis

With the serious aging of the population, the incidence of fragility fractures of the pelvis(FFPs) has gradually increased, which has become a public problem affecting the living quality of the elderly. When a surgical treatment is chosen, the procedure should be as minimal invasive as possible and avoid all surgical complications. In recent years, different techniques for percutaneous or less invasive fixation of the posterior pelvic ring have been developed. Their advantages and limitations are presented: sacroplasty, iliosacral screw osteosynthesis, cement augmentation, transiliac internal fixation, transsacral osteosynthesis, lumbopelvic fixation. The purpose of this paper is to review the classification and minimally invasive treatment of FFP.

Open reduction and screw/plate osteosynthesis of metacarpal fractures

Anatomic reduction and stabile fixation for immediate mobilisation and restoration of unrestricted function. Instabile metacarpal fractures with or without malrotation, dislocated metacarpal fractures with malrotation or finger extension deficit, longitudinally shortened metacarpal fractures with finger extension deficit. Persistent infections (empyema, osteomyelitis, phlegmon) SURGICAL TECHNIQUE: Longitudinal intermetacarpal incision along the fracture zone, debridement of the fracture zone with retainment of periost, anatomic reduction and retention of spiral fractures with at least two lag screws or retention of comminuted or transverse fractures with locking plate osteosynthesis while retaining periost. Buddy splinting of the corresponding finger to enable immediate mobilisation without weight bearing for 6weeks. Locking plate osteosynthesis and compression screw osteosynthesis after anatomic reduction of metacarpal fractures proved to be very reliable with alow complication rate and agood functional outcome (modified Mayo Wrist Score [MMWS]: mean88 (20-100); Disabilities of Arm, Shoulder, and Hand (DASH) questionnaire: mean 41(24-86)).

The “Apple-Bite-Fracture”: ACL rupture combined with posterolateral tibia plateau fracture

Aims and Objectives: Anterior cruciate ligament (ACL) ruptures are often concomitated by posterolateral bone bruise in the MRI. This is caused by a ventral subluxation of the tibia and impact of the femur in the posterolateral tibia plateau. In some cases, this impact causes a fracture of the posterolateral tibia plateau, the so-called Apple-Bite-Fracture. The increased posterior slope can cause additional instability and has to be considered as a risk factor for ACL failure. In this study we investigated the short term clinical outcomes of patients with this combined injury. Materials and Methods: Retrospective study of 14 patients (mean age 46 ± 12,3) (8 male, 6 female) with a mean follow up of 23,75 months. Different treatment strategies were analyzed. The clinical evaluation included visual analog score (VAS) increasing from 0-10 for Pain, IKDC Score, Rasmussen score as well as a clinical evaluation. Results: First analysis of the treatment options revealed a non-uniformed therapy strategy. In three patients the ACL tear was treated nonsurgical. In 11 patients the ACL tear was addressed surgical: six times the ACL was reconstructed with hamstring tendon graft, two times the ACL was sutured. Two patients treated with a non-reconstructive technique to promote healing (“healing response”). In one patient a tibial eminence fracture was fixated with a screw. The fracture of the posterolateral tibia plateau was in nine cases minimally invasive reduced and fixated with a screw osteosynthesis in jail technique. Two patients needed posterior buttress plate. Three times the large bone defect has been augmented with autologous bone graft from the pelvis. The postoperative clinical testing did not reveal any persisting knee instabilities. All patient had a non-limited ROM. No significant differences in ROM in comparison to the contralateral knee was seen. One patient reported persisting knee pain (VAS 3). All other patients reported no pain (VAS 0). Subjective IKDC score was 78,18 (71,3 - 83,9; ± 5,68). Clinical Rasmussen scores ranged from 27 to 30 (mean 27, ± 3,0). Rasmussen radiological results ranged from 16 to 18, mean 16,67 (± 1,15). Conclusion: Despite a very small patient number and leck of statistical power the new patient-spedific mini-metal implant seems to be a good options fort he treatment of middle-aged patients who already underwent frustane cartilage surgery. In these relatively rare caes early unicompartimental arthroplasty can be prevented. Further clinical studies with larger patient collectives have to prove the effectiveness of this new technique.

Screw osteosynthesis of transverse fracture of the patella in children

ObjectivePatella fractures in children are rare, with an incidence of less than 1% of all pediatric fractures. Literature describes different surgical techniques and outcomes, but there is not a specified...

Practicability of a locking plate for difficult pathologies of the scaphoid.

Headless compressions screws are the most implanted devices for scaphoid fractures and nonunions. For cases when screw osteosynthesis is not possible, a special locking plate for scaphoid reconstruction has been developed. The purpose of this study was to evaluate the safety and practicability of this device for difficult scaphoid pathologies. Between March 2010 and December 2014, 20 patients (age range 16-59years) were treated with scaphoid locking plate osteosynthesis. In 17 cases it was due to scaphoid nonunion or delayed union and in three cases to treat a complex multi-fragmentary fracture of the scaphoid. Most of the initial fractures were located either in the proximal third (n = 9) or the middle third (n = 8) of the scaphoid. Mean follow-up was 14.6 ± 8.9months (range 2-30months). All three scaphoid fractures (100%) showed bony healing in the CT scan after 2.7 ± 0.6months. 15 of 17 (88.2%) patients with scaphoid nonunion demonstrated bony healing in the latest CT scan at an average of 6.2 ± 8.1months (range 2-11months) after scaphoid reconstruction. Range of motion (extension/flexion) was 104° ± 18.4° (range 80°-150°) and about one third less than the unaffected side. The average grip strength averaged 38.2kg on the operated side and 44.1kg on the unaffected side after surgery. 13 plates (65%) had to be removed due to impaction of the plate or protrusion of the screws. This new locking device for scaphoid reconstruction seems to be a safe, useful and reliable tool in the treatment of difficult nonunions or multi-fragmentary scaphoid fractures. The practicability is convincing and satisfying fusion rates can be accomplished. However, most patients require hardware removal. We recommend using this plate as a rescue option when a stable osteosynthesis is necessary for the healing process and screw fixation has already failed or is not possible.

Radiological and Clinical Outcome After Screw Osteosynthesis of Radial Head Fractures

Radiological and Clinical Outcome After Screw Osteosynthesis of Radial Head Fractures

Percutaneous screw techniques for the pelvic ring and acetabulum

In the treatment of pelvic ring and acetabular fractures percutaneous screw osteosynthesis provides the advantage of minimal soft tissue damage. The techniques are frequently used in combination with open osteosynthesis and less frequently as stand-alone procedures. A preoperative planning with the aid of computed tomography (CT) and knowledge of the intraoperative radiological fluoroscopy adjustment are prerequisites for an accurate placement of the screws. This article describes the indications and techniques for frequently used percutaneous screws.

Fragility fractures of the pelvis

Fragility fractures of the pelvis are increasing in frequency. In most cases patients suffer aminor injury, have intense pain in the pelvic region and impaired mobility. The new fragility fractures of the pelvis (FFP) classification distinguishes between four types with increasing instability. The FFP typesI and II are treated conservatively. For FFP typesIII and IV and typeII with unsuccessful conservative treatment, minimally invasive stabilizing techniques are recommended. Both the posterior and anterior pelvic ring must be stabilized. Alternative techniques for dorsal stabilization are iliosacral screw and transsacral bar osteosynthesis, transiliac internal fixator and lumbopelvic fixation. External fixation, retrograde transpubic screw fixation, anterior internal fixation and plate and screw osteosynthesis are alternatives for the anterior pelvic ring. Treatment of fragility fractures of the pelvis should be carried out as part of an orthogeriatric co-management.

The Inverted Coronoid-Ramus Graft for Condylar Reconstruction

The purpose of this article is to describe a creative, versatile technique for condylar reconstruction using autogenous mandibular bone. The technique has been used for reconstruction of small condyle and/or ramus defects (approximately 35 to 40mm in length) typically associated with condylar hyperplasia, condylar tumors, idiopathic condylar resorption, and failed reconstruction attempts.The technique involves excision of the ipsilateral coronoid process-mandibular ramus, inverting it and rotating the segment 180° along its horizontal axis to replace the excised condyle. The resultant graft simulates the morphology of the posterior aspects of the ramus and condyle and has been shown to resist resorption typical of endochondral bone grafts harvested from the rib or iliac crest. Grafting is carried out via vestibular and preauricular or endaural incisions. Four cases followed over a period of 3 to 40months (average, 21months) are presented. No adverse functional results, including ankylosis, removal of hardware or adverse remodeling, have occurred. A period of intermaxillary fixation is used because it is considered beneficial for intra-articular scarring of the subglenoid fossa pad (disc or retrodiscal tissue and fibrocartilage) and initial healing. Physical therapy has not been prescribed. The inverted coronoid graft is a versatile technique when virtual surgical planning is used to assess feasibility, as well as defect and graft dimensions; fabricate custom bone plate and drilling guides; and determine screw osteosynthesis sites. In general terms, a post-reconstruction opening of 35mm allows for adequate function and guards from contralateral symptomatic hypermobility given disparate right- and left-sided joint mechanics. In the cases described, a mean of 40.5mm was achieved; however, in 2 of these cases, this was measured with undesirable asymptomatic (preoperative) deviation to the ipsilateral side by greater than 4mm and by 6mm. The inverted coronoid graft technique reduces operative time, can be executed with few external scars, and reduces the number of operative fields.

Use of Transgingival Lag Screw Osteosynthesis in the Management of Alveolar Process Fracture.

The purpose of this study is to check the efficacy of transgingival lag screw osteosynthesis in alveolar process fractures of maxilla and mandible. A single-arm nonrandomized observational study was performed for the treatment of alveolar process fractures of maxilla and mandible. In this study, 20 mixed age group patients with alveolar process fracture were included. All the patients were treated by a 2.0-mm transgingival screw fixation under local or general anesthesia. All the patients were evaluated for fracture stability, anatomical reduction, bone loss and bone resorption of alveolar process, tooth loss, and wound infection at 3 months of follow-up. A simple descriptive statistical analysis was done to evaluate the parameters and it was shown that the treatment of alveolar process fracture with two or three lag screws provides adequate fracture stability and anatomical reduction with no signs of bone loss and tooth loss, and wound infections were noted post lag screw fixation. The study concludes that transgingival lag screw fixation is a suitable alternative for alveolar process fractures in all the age groups and two to three lag screws are generally sufficient to fix fractured alveolar process either under local anesthesia or general anesthesia.

When and How to Operate Fragility Fractures of the Pelvis?

Fragility fractures of the pelvis (FFP) are an entity with an increasing frequency. The characteristics of these fractures are different from pelvic ring fractures in younger adults. There is a low energy instead of a high energy trauma mechanism. Due to a specific and consistent decrease of bone mineral density, typical fractures in the anterior and posterior pelvic ring occur. Bilateral sacral ala fractures are frequent. A new classification system distinguishes between four categories with increasing loss of stability. The subtypes represent different localizations of fractures. The primary goal of treatment is restoring mobility and independency. Depending on the amount of instability, conservative or surgical treatment is recommended. The operative technique should be as less invasive as possible. When the broken posterior pelvic ring is fixed operatively, a surgical fixation of the anterior pelvic ring should be considered as well. FFP Type I can be treated conservatively. In many cases, FFP Type II can also be treated conservatively. When conservative treatment fails, percutaneous fixation is performed. FFP Type III and FFP Type IV are treated operatively. The choice of the operation technique is depending on the localization of the fracture. Iliosacral screw osteosynthesis, transsacral bar osteosynthesis, transiliac internal fixation, and iliolumbar fixation are alternatives for stabilization of the posterior pelvic ring. Plate osteosynthesis, retrograde transpubic screw, and anterior internal fixation are alternatives for stabilization of the anterior pelvic ring. Postoperatively, early mobilization, with weight bearing as tolerated, is started. Simultaneously, bone metabolism is also analyzed and its defects compensated. Medical comorbidities should be identified and treated with the help of a multidisciplinary team.

Arthroscopic Reconstruction of Multifragmented Anteroinferior Glenoid Rim Fractures.

The optimal treatment of anteroinferior glenoid rim fractures remains a matter of debate. Surgical repair aims to prevent persistent instability and osteoarthritic changes of the glenohumeral joint1-3 and is recommended in patients with a subluxated humeral head and substantial displacement of the fracture fragment(s)3-5. Arthroscopic reconstruction with suture anchors was described by Sugaya et al. for large solitary glenoid rim fractures using an indirect reduction and fixation via labral repair6. We present the arthroscopic reconstruction of a multifragmented anteroinferior glenoid rim fracture using a modified knotless anchor technique and bioabsorbable pins. The additional fixation and compression may improve reduction and consolidation of the fracture. The patient is placed in the lateral decubitus position with the affected arm fixed in a traction device. A standard posterior, an anterosuperior (suprabicipital), and a deep anteroinferior portal are required for this minimally invasive technique. A posterolateral portal may be required additionally. First, a diagnostic arthroscopy is performed to identify possible concomitant lesions. Labral repair enables an indirect reduction of the attached fracture fragments and is achieved by the aid of knotless suture anchors. Temporary reduction using Kirschner wires can be applied. Bioabsorbable pins can be used for additional ultimate fixation and compression of the fracture fragments. A variety of surgical techniques for the reconstruction of glenoid rim fractures have been described in the literature, including open or arthroscopic screw osteosynthesis using either metallic or bioabsorbable screws3,6-10. Screw osteosynthesis, however, is not a feasible option for fractures with multiple small fragments3. Isolated suture anchor reconstruction represents another alternative6. Good clinical results and a high subjective satisfaction rate, however, can also be achieved by nonoperative treatment, depending on the patient and fracture characteristics3,10-12. This minimally invasive technique enables an almost anatomical reconstruction of the glenoid rim with a minor risk of hardware impingement compared with screw osteosynthesis.

Long term clinico-radiological outcome of osteosynthesis in patients with femoral neck fracture: A retrospective study

Introduction: Fracture of the neck of femur continues to be one of the major orthopaedic injuries. It occurs in elderly patients with osteoporosis or in young patients suffering high energy trauma. Aims and Objectives: To evaluate long term clinico-radiological outcome of osteosynthesis in patients with femoral neck fracture. Material and Methods: Fifty patients of femoral neck fracture who underwent osteosynthesis with lag screw fixation or with valgus intertrochanteric osteotomy were studied. The patients were divided into 2 groups; Group-I (n=16) comprised of patients in whom osteosynthesis with lag screws was done and Group-II (n=34) patients had undergone valgus intertrochanteric osteotomy. Results: In Group-I at an average follow up of 41.8 weeks no patient had non-union or AVN, all heads were viable, 6.25% had OA hip & intraarticular implant penetration, 93.7% had Harris hip score from good to excellent, d’Aubigne & Postel score from good to very good & SF-36 score below 10 whereas at an average follow up of 142.37 weeks 6.25% had non-union, 75% heads were viable, 25% had AVN & OA hip, 6.25% had intraarticular implant penetration, 75% had Harris hip score from good to excellent, d’Aubigne & Postel score from good to very good & SF-36 score below 10. In Group-II at an average follow up of 55.44 weeks 2.94% had non-union, 94.12% heads were viable, 5.88% had AVN, 8.82% had OA hip, no intraarticular implant penetration, 88.23% had Harris hip score from good to excellent, 91.17% had d’Aubigne & Postel score from good to very good & 79.41% had SF-36 score below 10 whereas at an average follow up of 159.3 weeks 2.94% had non-union, 82.36% heads were viable, 17.64% had AVN, 41.17% had OA hip, 2.94% had intraarticular implant penetration, 73.53% had Harris hip score from good to excellent, 72.22% had d’Aubigne & Postel score from good to very good & 70.58% had SF-36 score below 10. Conclusion: Rate of union was found to be better in patients managed with valgus intertrochanteric osteotomy than with lag screw osteosynthesis. The incidence of avascular necrosis seems to be higher in patients of group-I as compared to group-II patients. The overall clinical & radiological outcomes in both groups became worse on long term follow up.

Risk of extrapelvine vascular injuries in osteosynthesis with gliding hip screws

Dynamic hip screw (DHS) osteosynthesis represents one of the most frequently performed fixation methods in orthopedic practice. The purpose of this study was to determine the potential risk of vascular damage by DHS side-plate screws (PS) and plunging instruments for individual femoral vessels and screw positions. In ten hemipelvic/leg specimens mounted with a large femur distractor, a DHS system with a four-hole side-plate was inserted. PS were inserted in 3 consecutive courses with different inclinations in the frontal plane of 0° (group 1), - 30° posterior (group 2) and + 30° anterior (group 3) in relation to the side-plate's surface, resulting in 120 PS positions. After screw tightening, the soft tissues on the medial side of the femur were dissected and investigated for vascular compromise; in each course, the effect of overshot instruments within a range of 50mm beyond the side-plate's surface was also tested. Totally, 37/120 screw positions (31%) revealed potential vascular compromise which comprised of 15/120 (13%) direct hits by screw tips and 22/120 (18%) potential impacts by plunging instruments. The deep femoral artery system (DFA) was significantly (p = 0.007) most often affected but no significant differences for individual vascular structures were seen. Direct vascular impacts occurred significantly more often (p = 0.0047) in screws with 0° inclination compared to + 30° inclination (p = 0.017). Significant differences among individual screw positions were only found in group - 30° with direct vessel contacts (p = 0.038). The DFA system is significantly more at risk while significant preference of a certain vessel is missing. Our data indicate that more than 30% of 120 screw positions in DHS osteosynthesis revealed a potential danger of vascular compromise, when surgical principles are denied in hip fracture fixation. Though vascular complications are infrequently encountered in DHS osteosynthesis they have to be considered as a potential complication when surgical principles are not followed in this anatomic area.

Intercondylar eminence fracture treated by resorbable magnesium screws osteosynthesis: A case series

IntroductionTibial spine avulsion fractures are mostly a paediatric injury which appropriate treatment is currently debated in literature. The choice between conservative and surgical treatment is based on the radiographic classification of Meyers-McKeever. The most diffused surgical techniques involve either internal fixation devices (screws) or bone tunnels fixation with resorbable sutures. Today, a third option is represented by resorbable magnesium screws which could combine the best features of the two classical systems. Objective of this study is to investigate the efficacy of these new devices in the surgical treatment of tibial spine avulsions. Materials and methodsSince 2014 we have seen seven patients with tibial eminence fracture. Patients underwent clinical and radiological examination (MRI, CT scan) before surgery. Only 3 patients that presented with a grade III or IV lesion were treated surgically with internal fixation with magnesium resorbable screws. In post-operative follow-up, functional recovery was evaluated at 1, 2, 4, 6 and 12 months, clinically and by X-ray. Lysholm and IKDC scores were submitted at 1, 2, 6 and 12 months. MRI was repeated at 6 and 12 months. ResultsAll three surgical patients showed progressive clinical and functional improvement during the follow-up period. The first case showed a quicker overall recovery rate, which might be due to the lower grade of the lesion. Radiographs and MRI evaluation showed regular healing of the injury. The devices appeared completely resorbed at the 6 months follow-up and replaced by newly formed bone at the 12 months follow-up. ConclusionsThe treatment of tibial spine avulsion fractures with arthroscopic reduction and internal fixation (ARIF) technique by magnesium resorbable screws seems to result in an excellent functional recovery without complications related to fixation devices, which were completely resorbed after 6 months and replaced by newly formed bone after 12 months. This new method could be considered as an alternative option to classic techniques by non resorbable fixation devices or bone tunnel fixation. Further studies are needed in order to evaluate the efficacy of these new devices in a wider group of patients.