Hinged External Fixation Research Articles

Two case reports of lower limb posttraumatic angular deformities correction by dynamic hinged external fixation

The aim of this study was to present two patients with lower limb posttraumatic angular deformity treated by dynamic hinged external fixation. CD-V mode Mitkovic type external fixator had been used in both cases for correction of these deformities. The method is based on hemicallotasis - bone callus distraction after a partial transversal bone cut (hemocorticotomy). The first patient had varus-recurvatum posttraumatic deformity of the ankle joint. Operation time was 65 min and hospital stay was 9 days. Superficial pin-track infection was resolved by the pin removal and by daily wound toilette. The second patient had varus-antecurvatum malunion deformity of the femoral diaphysis. Operation time was 50 min and hospital stay was 6 days. Mild knee contracture had been successfully treated by physical therapy. Angular deformity correction had been performed by distraction (for the first patient) and compression (for the second patient) in the fixator frame. Hemicallotasis of femur or tibia using CD-V mode Mitkovic type external fixator is a good alternative in the treatment of posttraumatic lower limb angular deformities, providing minimal surgical trauma and maximal use of the bone osteogenetic capacity. Gradual compression or distraction in the fixator frame allows to perform accurate angular correction in both coronal and sagital plane in one act.

Hinged External Fixation in the Treatment of Knee Dislocations

Our hypothesis was that patients treated with hinged external fixators as an adjunct to multiple-ligament reconstruction would have fewer reconstruction failures than patients treated without external fixation. In this prospective randomized study, patients with a knee dislocation either underwent ligament reconstruction with placement of an external hinged knee brace following surgery (Group A) or underwent ligament reconstruction with placement of a hinged external fixator (Compass Knee Hinge) for six weeks instead of the brace (Group B). The patients were followed clinically and were evaluated with physical examination, Lysholm and International Knee Documentation Committee knee scores, visual analog scale pain scores, and status regarding return to work and activities. One hundred patients with 103 knee dislocations were enrolled. Seventy-seven patients with seventy-nine dislocations (thirty-two in Group A and forty-seven in Group B), with a minimum follow-up interval of twelve months, were available for evaluation. The mean duration of follow-up was thirty-nine months (range, twelve to eighty-six months). Nine patients (29%) in Group A had failed reconstructions compared with seven (15%) in Group B (p = 0.15). Group-A patients had twenty-two (21%) of 105 reconstructed individual ligaments fail compared with eleven (7%) of 157 reconstructed ligaments in Group B. The difference in ligament failure was significant (p < 0.001; power > 0.8), with more favorable results for the patients managed with the external fixation. Hinged external fixation as a supplement to reconstruction following knee dislocation was associated with fewer failed ligament reconstructions compared with external bracing. Patients presenting with highly unstable knee dislocations should be considered for hinged external fixation to supplement initial reconstructive procedures.

Radial nerve injury secondary to use of hinged elbow external fixators

Objective To discuss causes and treatment outcomes of radial nerve injury related to hinged external fixators applied to the elbow,enhance understanding of the injury and thereby reduce its clinical incidence.Methods The study involved five cases who experienced radial nerve injury in the wake of application of unilateral hinged external fixators to the elbow.Exploration and neurolysis was perfomed at 3-12 weeks after injury since no signs of nerve recovery.Afterwards,follow-up was made for all cases.Results Causes of radial nerve injury were as follows:proximal humerus Schanz screws stretched and compressed radial nerve by tethering soft tissues into cicatricial bands in two cases; distal humerus Schanz screws compressed radial nerve by tethering soft tissues adjacent to radial nerve to cicatricial bands in one case; distal humerus Schanz screws compressed radial nerve in motion of the elbow by tethering thickened intermuscular septa and further forcing the enlargement of muscle force in two cases.Forces of muscles supplied by radius nerve reached fourth or fifth rank at postoperative one-year follow-up.Conclusions Radial nerve is vulnerable in the application of unilateral hinged external fixators to the elbow due to its special path and relative stability.Accordingly,injury to radial nerve can be reduced and even avoided by knowing its anatomy features and standardizing the operation in use of external fixators.Exploration and treatment immediately after the confirmation of radial nerve injury can achieve good prognosis. Key words: Elbow joint; Radial nerve; External fixators

Hinged External Fixator and Open Surgery for Severe Elbow Stiffness With Distal Humeral Nonunion

Joint stiffness is a common complication of elbow trauma. Treating elbow stiffness is challenging, especially in patients with severe elbow stiffness with distal humeral nonunion. To improve treatment outcomes, the authors applied a hinged external fixator after performing open reduction and internal fixation and evaluated the clinical outcome. Between 2005 and 2011, eleven patients with elbow stiffness and distal humeral nonunion underwent open arthrolysis, surgical reduction, internal fixation, hinged external fixation, and selective bone grafting. The ulnar nerve was anteriorly transposed in all patients. Elbow range of motion, Mayo Elbow Performance Score, and radiographs were assessed pre- and postoperatively. All patients achieved solid union in an average of 5.6 months. Preoperatively, mean flexion was 86.8°, mean extension was 45.5°, and mean total range of motion was 41.3°. Postoperatively, mean flexion was 125.9°, mean extension was 11.8°, and mean total range of motion was 114.1°. Mean Mayo Elbow Performance Score also significantly improved from 59 points preoperatively to 87.2 points postoperatively, and 6 patients were scored as excellent (more than 90 points), 3 good (75-90 points), and 2 fair (60-74 points) according to the Mayo Elbow Performance Score. A stiff elbow with distal humeral nonunion can be treated successfully using a unilateral hinged external fixator to supplement the open reduction and internal fixation. A hinged external fixator was an effective rehabilitation method for improving range of motion and maintaining joint stability.

A novel method for defining the Greyhound talocrural joint axis of rotation for hinged transarticular external skeletal fixation

In order to apply hinged transarticular external skeletal fixation for stabilization of the injured canine tarsal joint, knowledge of the three-dimensional (3D) location and orientation of the transverse axis is necessary. This method of immobilization may be used as a primary or adjunctive method of stabilisation for a large number of traumatic conditions. Using pin-mounted markers in the cadaveric Greyhound crus and talus, a closed-form solution of absolute orientation was used to identify, on radiographs, the lateral and medial locations of the transverse axis by tracking the 3D excursions of the markers during flexion and extension. A line was drawn across the dorsal aspect of the calcaneus from the most dorsal point on the distal articular surface(proximal intertarsal joint: PIJ) to the most dorsal point on its proximal articulation with the body of the talus, and the location of the centre of rotation was expressed in terms of the length of that line. In seven Greyhound tarsal joints, the medial end of the axis was located 73 ± 10% proximal to the PIJ and 11 ± 7% dorsal to the line. The lateral end was 73 ± 9% proximal tothe PIJ and -2 ± 3% plantar to the line.

Open arthrolysis and hinged external fixation for posttraumatic ankylosed elbows

An ankylosed elbow is defined as an elbow having a range of motion of 0°. Movement is extremely limited. This study retrospectively analyzes the results of arthrolysis and hinged external fixation performed on 15 patients suffering from ankylosed elbows. Fifteen completely ankylosed elbows were treated by arthrolysis and hinged external fixation. Patients comprised nine men and six women, with a mean age of 37.93 years (37.93 ± 9.68) when arthrolysis was performed. Before surgery, the elbows were ankylosed at various angles ranging from 30° to 85°. Eleven patients underwent arthrolysis by medial and lateral approaches, three patients by the posterior approach, and one patient by posterior and lateral approaches. Hinged external fixators were applied to all patients. Subcutaneous anterior transposition of the ulnar nerve was performed in all patients. All patients received satisfactory follow-up. The range of motion of the elbow improved from 0° preoperatively to a postoperative mean of 115.67° (115.67 ± 23.29). The Mayo Elbow Performance Score improved from a mean of 67.67 ± 11.00 to 86.67 ± 8.38 points, with excellent results in nine patients, good in five, and fair in one. This difference is statistically significant (t = -6.862; p < 0.001). Open arthrolysis and monolateral hinged external fixation are effective in treating posttraumatic ankylosed elbow. Arthrolysis should be performed by a combination of lateral and medial approaches. In addition, routine hinged external fixation and anterior transposition of the ulnar nerve may improve the postoperative recovery of elbow stiffness.

Open Release and a Hinged External Fixator for the Treatment of Elbow Stiffness in Young Patients

Elbow stiffness is a well-recognized complication following elbow trauma, but little information is available regarding the surgical treatment of elbow stiffness in children and adolescents. This article presents the results of open arthrolysis with twin incisions and a hinged external fixator to treat severe elbow contracture in children and adolescents. Twenty-one patients (mean age, 14.9 years; range, 7-19 years) were evaluated. All patients underwent surgery using a hinged external fixator and a combined mediolateral approach to address the elbow contracture. Mayo elbow score and range of motion (ROM) were measured preoperatively and at 3, 12, and 24 months postoperatively. All but 1 patient achieved a functional ROM of 100°. Preoperatively, mean flexion was 70.2° (range, 30°-100°), extension was 42.6° (range, 0°-80°), and total ROM was 28.5° (range, 0° to 80°); postoperatively, mean flexion improved to 122.8° (range, 90°-140°), extension to 10° (range, 0°-30°), and total ROM to 114.5° (range, 60°-140°). The Mayo elbow score improved from a mean of 48 points (range, 35-65 points) to 90 points (range, 75-100 points), and 9 patients had excellent results, 7 had good results, 4 had fair results, and 1 had a poor result. No significant differences existed between postoperative measurements at 3, 12, and 24 months. No pin-tract infections or deep infections occurred, and no vascular or neurological complications were noted. Surgical treatment of elbow stiffness using a hinged external fixator and open arthrolysis is an effective procedure in children and adolescents.

Paper 189: Stabilization of Knee Dislocations Using a Hinged External Fixator: A Prospective Randomized Study

Paper 189: Stabilization of Knee Dislocations Using a Hinged External Fixator: A Prospective Randomized Study

Paper 190: Fracture Dislocation of the Knee: A Prospective Evaluation of Fracture Fixation and Early Ligament Reconstruction with the Use of a Hinged External Fixator

Paper 190: Fracture Dislocation of the Knee: A Prospective Evaluation of Fracture Fixation and Early Ligament Reconstruction with the Use of a Hinged External Fixator

Hinged External Fixation Distraction for Treatment of First Metatarsophalangeal Joint Arthritis

Treatment for hallux rigidus varies from joint preservation to joint destructive procedures. The objective of the present study was to report an alternative method of treatment of hallux rigidus using hinged external fixation distraction of the first metatarsophalangeal joint and to present our surgical technique. Ten distractions were performed in 9 patients (9 female feet [90%] and 1 male foot [10%]). The mean age at surgery was 41.0 (range 20 to 64) years. All patients had stage II or III hallux rigidus on the Regnauld classification system for hallux rigidus. The patients were evaluated clinically and radiographically before and after the distraction treatment. The mean period of fixation was 16.40 (range 7 to 21) weeks. Six of the patients (60%) with distraction experienced pin tract infections that were treated with oral antibiotics. The reported mean preoperative categorical pain score in 7 patients (7 feet) was 8.2 (range 5 to 10), and the postoperative score was 0.83 (range 0 to 2; p = .001). Of the 6 patients (6 feet) who responded to the remaining portion of the survey, 4 (66.67%) were very satisfied with their results, and 2 (33.33%) were satisfied with their surgical result. None of the patients required additional surgical treatment during the mean 2.2 (range 1.2 to 3.3) years of follow-up. Hinged first metatarsophalangeal joint distraction with external fixation has been shown to be a viable treatment option for joint preservation for stage II and III hallux rigidus in the short term.

On the Estimate of the Two Dominant Axes of the Knee Using an Instrumented Spatial Linkage

This article presents the validation of a technique to assess the appropriateness of a 2 degree-of-freedom model for the human knee, and, in which case, the dominant axes of flexion/extension and internal/external longitudinal rotation are estimated. The technique relies on the use of an instrumented spatial linkage for the accurate detection of passive knee kinematics, and it is based on the assumption that points on the longitudinal rotation axis describe nearly circular and planar trajectories, whereas the flexion/extension axis is perpendicular to those trajectories through their centers of rotation. By manually enforcing a tibia rotation while bending the knee in flexion, a standard optimization algorithm is used to estimate the approximate axis of longitudinal rotation, and the axis of flexion is estimated consequently. The proposed technique is validated through simulated data and experimentally applied on a 2 degree-of-freedom mechanical joint. A procedure is proposed to verify the fixed axes assumption for the knee model. The suggested methodology could be possibly valuable in understanding knee kinematics, and in particular for the design and implant of customized hinged external fixators, which have shown to be effective in knee dislocation treatment and rehabilitation.

Management of severe extra-articular contracture of the elbow by open arthrolysis and a monolateral hinged external fixator

Arthrolysis and dynamic splinting have been used in the treatment of elbow contractures, but there is no standardised protocol for treatment of severe contractures with an arc of flexion < 30 degrees . We present our results of radical arthrolysis with twin incisions with the use of a monolateral hinged fixator to treat very severe extra-articular contracture of the elbow. This retrospective study included 26 patients (15 males and 11 females) with a mean age of 30 years (12 to 60). The mean duration of stiffness was 9.1 months (5.4 to 18) with mean follow-up of 5.2 years (3.5 to 9.4). The mean pre-operative arc of movement was 15.6 degrees (0 degrees to 30 degrees ), with mean pre-operative flexion of 64.1 degrees (30 degrees to 120 degrees ) and mean pre-operative extension of 52.1 degrees (10 degrees to 90 degrees ). Post-operatively the mean arc improved to 102.4 degrees (60 degrees to 135 degrees ), the mean flexion improved to 119.1 degrees (90 degrees to 140 degrees ) and mean extension improved to 16.8 degrees (0 degrees to 30 degrees ) (p < 0.001). The Mayo elbow score improved from a mean of 45 (30 to 65) to 89 (75 to 100) points, and 13 had excellent, nine had good, three had fair and one had a poor result. We had one case of severe instability and one wound dehiscence which responded well to treatment. One case had deep infection with poor results which responded well to treatment. Our findings indicate that this method is very effective in the treatment of severe elbow contracture; however, a randomised controlled study is necessary for further evaluation.

The Treatment of Intra-articular Calcaneus Fractures with Severe Soft Tissue Damage with a Hinged External Fixator or Internal Stabilization: Long-term Results

We developed a hinged external fixator for the treatment of dislocated intra-articular calcaneus fractures with severe soft tissue damage. The external fixation was performed with a known external fixator system. The screw insertion points were biomechanically tested by defining a virtual rotation axis through the center of the talus to allow early active motion in the ankle joint. Long-term follow-up was performed after an average of 7.3 years. Results were graded with the American Orthopaedic Foot and Ankle Society (AOFAS) score. Radiographs were reviewed according to Sanders classification. Four open fractures and 33 cases with extremely swollen soft tissue, blisters, or compartment syndromes were treated. In 24 cases (64.9%), the hinged fixator was the final method of treatment (group I). A change to open reduction with internal fixation was performed in 13 fractures (35.1%) when soft tissue problems were minimal (group II). There were no late amputations, osteomyelitis, or malunions. According to Sanders classification, group I consisted of 14 type II, 8 type III, and 2 type IV fractures. Pin loosening or pin infection was seen in 4 cases, but there was no redislocation. The Böhler's angle improved in 43%, gaps in the posterior facet were closed in 41%, and any shortening or deviation of the axis was corrected in 82% of the cases. The AOFAS score for the group averaged 66.5. According to Sanders classification, group II consisted of 8 type II and 5 type III fractures. The Böhler's angle improved in 88%, and gaps in the posterior facet were closed in 87%. Any shortening or deviation of the axis was corrected in 95%, and the AOFAS score averaged 61.3. Significant differences in patient outcome scores between open reduction with internal fixation and hinged fixator were not found. P value was > .05. The hinged external fixator frame can be used in all calcaneus fracture types without soft tissue limitation. The hinged fixator allows early movement in the ankle joint, the risk of infection is minimized, and secondary plate fixation remains possible.

Advantages of the Ilizarov external fixation in the management of intra-articular fractures of the distal tibia

BackgroundTreatment of distal tibial intra-articular fractures is challenging due to the difficulties in achieving anatomical reduction of the articular surface and the instability which may occur due to ligamentous and soft tissue injury. The purpose of this study is to present an algorithm in the application of external fixation in the management of intra-articular fractures of the distal tibia either from axial compression or from torsional forces.Materials and methodsThirty two patients with intra-articular fractures of the distal tibia have been studied. Based on the mechanism of injury they were divided into two groups. Group I includes 17 fractures due to axial compression and group II 15 fractures due to torsional force. An Ilizarov external fixation was used in 15 patients (11 of group I and 4 of group II). In 17 cases (6 of group I and 11 of group II) a unilateral hinged external fixator was used. In 7 out of 17 fractures of group I an additional fixation of the fibula was performed.ResultsAll fractures were healed. The mean time of removal of the external fixator was 11 weeks for group I and 10 weeks for group II. In group I, 5 patients had radiological osteoarthritic lesions (grade III and IV) but only 2 were symptomatic. Delayed union occurred in 3 patients of group I with fixed fibula. Other complications included one patient of group II with subluxation of the ankle joint after removal of the hinged external fixator, in 2 patients reduction found to be insufficient during the postoperative follow up and were revised and 6 patients had a residual pain. The range of ankle joint motion was larger in group II.ConclusionIntra-articular fractures of the distal tibia due to axial compression are usually complicated with cartilaginous problems and are requiring anatomical reduction of the articular surface. Fractures due to torsional forces are complicated with ankle instability and reduction should be augmented with ligament repair, in order to restore normal movement of talus against the mortise. Both Ilizarov and hinged external fixators are unable to restore ligamentous stability. External fixation is recommended only for fractures of the ankle joint caused by axial compression because it is biomechanically superior and has a lower complication rate.

Treatment of chronically unreduced complex dislocations of the elbow.

Chronic dislocation of the elbow is an exceedingly disabling condition associated with severe instability, limitation of elbow function and significant pain. Due to the potentially conflicting goals of restoring elbow stability and regaining a satisfactory arc of motion, successful treatment is a challenge for the experienced trauma surgeon. We report our treatment strategy in three patients suffering from chronically unreduced fracture-dislocations of the elbow. The treatment protocol consists of in situ neurolysis of the ulnar nerve, distraction and reduction of the joint using unilateral hinged external fixation and repair of the osseous stabilizers. A stable elbow was achieved in all patients, without the need of reconstruction of the collateral ligaments. At final follow-up, the average extension/flexion arc of motion was 107° (range, from 100° to 110°). The average MEPI score at follow-up was 93, and the average DASH score was 19. This is a promising treatment protocol for the treatment of chronically unreduced complex elbow dislocations to restore elbow stability and regain an excellent functional outcome.

Interposition arthroplasty of the elbow with hinged external fixation for post-traumatic arthritis

This retrospective case series reviewed 9 men and 4 women (mean age, 41 years) with severe post-traumatic elbow arthrosis treated with interposition arthroplasty and temporary hinged external fixation. In 2 patients, treatment was considered to have failed because of early postoperative instability, and their results were classified as poor. The remaining 11 were followed up for a mean of 4 years (range, 1-11 years). The mean arc of flexion improved from 48 degrees before surgery to 110 degrees after surgery. The mean postoperative Broberg-Morrey score was 77 points, reflecting a mean improvement of 41 points (range, 13-68 points) and corresponding with 1 excellent, 4 good, 4 fair, and 4 poor results. Four patients had severe instability associated with bone loss of the distal humerus or trochlear notch. Interposition arthroplasty can improve elbow motion and function but at the expense of elbow stability despite hinged external fixation.

Dynamic and Functional Gait Analysis of Severely Displaced Intra-Articular Calcaneus Fractures Treated with a Hinged External Fixator or Internal Stabilization

The purpose of this article was to assess functional gait outcome. Fifty-five patients with severely displaced intra-articular calcaneus fractures and soft tissue damage were evaluated prospectively with computerized dynamic pedography and a clinical scoring scale. The treatment protocol assigned 30 patients to open reduction and internal fixation (ORIF) and 25 to closed reduction and stabilization with a biomechanically tested hinged external fixator. Gait parameter was evaluated by measuring plantar pressure distribution, length of a double-step, double-step duration, standing duration, effective foot length, and width of gait. Pedographic measurements were performed with a custom-made gait analysis system (medilogic Gangas, Berlin, Germany). Results were graded by an extended protocol of questionnaires and the American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot scales. Radiographs were reviewed according to the Sanders classification at the time of follow-up (7.3 years). All measurements were statistically analyzed (t test; Mann-Whitney U test). Aberrations were associated with all calcaneal fractures in both groups. Dynamic gait analysis showed gait asymmetry in all patients. The type of treatment (ORIF or a hinged fixator) of severely displaced calcaneus fractures did not affect gait analysis nor result in significantly different (P > .05) patient outcome scores. The gait analysis system allows a valid dynamic pedographic measurement. The hinged external fixator can be recommended in displaced intra-articular calcaneal fractures with severe soft tissue damage to reduce complications associated with ORIF. ACFAS Level of Clinical Evidence: 2c.

A Biomechanical Evaluation to Optimize the Configuration of a Hinged External Fixator for the Primary Treatment of Severely Displaced Intraarticular Calcaneus Fractures with Soft Tissue Damage

The purpose of this investigation was to develop an optimized hinged external fixator for the primary treatment of dislocated, intra-articular calcaneus fractures with associated soft tissue damage. To this end, a calcaneus model was made out of a polyurethane block, and a steel cylinder served as the ankle joint and was connected to a synthetic model of the tibia via a metal clamp. A saw cut served as the fracture in the model. A Steinmann nail and Schanz screw were placed in defined positions in the model and connected medially and laterally with longitudinal support rods. The fixator allowed a total of 20 degrees of plantar- and dorsiflexion, with rotation in the virtual axis of the upper ankle joint. Changes in the model fracture were measured during cyclical strain, and at different screw positions in the model tibia and calcaneus. Miniature force sensors located on the longitudinal support rods, and a plantar tension spring, were used to measure pressure and tension. Reproducible values were determined and, with the optimal configuration, shifting within the osteotomy was minimal. In the experimental configuration, optimal tibial screw placement was 70 mm proximal to the rotation axis of the upper ankle joint, and optimal placement of the Steinmann nail was in the posterior surface of the calcaneus. These findings indicated that the hinged fixator allows 20 degrees of ankle movement without alteration of the rotation axis, and suggest that this type of external fixator can be used in all types of calcaneal fracture regardless of the soft tissue damage. ACFAS Level of Clinical Evidence: 5c.

Subtotal Amputation Injuries in the Elbow Region Treated With a Hinged External Fixator

The established concept of hinged external elbow fixation can be applied to subtotal amputation injuries of the elbow, thus reducing the disadvantages of long-term transfixation of the elbow joint.

Unilateral Hinged External Fixation Frame for Elbow Compression Arthrodesis: The Stepwise Attainment of a Stable 90-Degree Flexion Position

We report a case of an elbow arthrodesis using a modular hinged external fixation device in a patient who sustained a complex high-energy injury. The extensive bone and soft-tissue loss and local infection precluded restoration of the articular anatomy. Other reconstructive options, including total elbow arthroplasty and allograft reconstruction, were not appropriate in this clinical situation. A transelbow hinged external fixator was applied with the elbow in extension. Subsequently, the hinge was brought gradually into 90 degrees of flexion as the elbow fused. Fixation and arthrodesis were successfully achieved by using this modular device, despite severe tissue loss and local septic complications. Furthermore, by gradually flexing the frame from full extension to 90 degrees , the need for flap coverage of the open wound was avoided.