经口咽入路寰椎前路钢板固定治疗不稳定性寰椎骨折

 目的探讨经口咽入路寰椎前路钢板内固定治疗不稳定性寰椎骨折的临床疗效。 方法2004年3月至2010年5月,采用经口咽入路寰椎前路钢板内固定治疗不稳定性寰椎骨折患者20例,男12例,女8例;年龄23~68岁,平均(47.7±13.9)岁。4例为寰椎前1/2 Jefferson骨折;8例为半环 Jefferson骨折;8例为前3/4 Jefferson骨折。患者均有不同程度的颈枕区疼痛,活动受限。疼痛视觉模拟评分(visual analog scale,VAS)为4~8分,平均(6.0±1.3)分。20例患者均选择行经口咽入路寰椎前路钢板内固定,随访通过临床和影像学检查评价其疗效。结果所有患者均获得随访,随访时间12~81个月,平均(48.5±20.0)个月。术中未出现螺钉松动、断裂,钢板移位,脊髓损伤,椎动脉损伤。20例患者共放置钢板20块,置入寰椎侧块螺钉40枚。术后CT显示有2枚螺钉过于靠近椎动脉沟,但是未出现临床症状。术后VAS评分为0~3分,平均(1.3±1.0)分。静态和动态的影像学资料显示,术后6个月所有患者均达到骨性愈合,寰枢关节旋转功能良好。随访期间无一例出现内植物相关的并发症。结论寰椎前路钢板内固定能获得坚固的骨性愈合和较低的并发症发生率,是治疗不稳定性寰椎骨折的一种有效方法。     

Implantation of the anterior atlantoaxial lateral mass intervertebral cage using the transoral approach

Background

The purpose of this study was to evaluate the possibility of implanting the anterior atlantoaxial lateral mass intervertebral cage, a new type of fixation, by the transoral approach.

Surgical treatment of lateral Hoffa fracture with a locking plate through the lateral approach

Objectives

The goal of this study is to determine the efficacy of the surgical treatment of lateral Hoffa fracture with a locking plate and cannulated or lag screws through the lateral approach.

Materials and methods

A total of 12 isolated lateral Hoffa fractures were identified during the study period (February 2005 to February 2010). All fractures were treated by open reduction through the lateral approach. Internal fixation was performed with a contoured locking plate and cannulated or lag screws introduced from the non-weight-bearing area of the cartilage surface of the lateral femoral condyle. Radiological and functional outcome analysis was performed using Knee Society scores.

Results

Bony union of Hoffa fracture was achieved in all patients. The articular surface of lateral femoral condyle was anatomically reduced. There was no loss of reduction and fixation. Functional outcome of knee measurements showed a continuous significant improvement over the follow-up period.

Conclusion

Fixation with a locking plate and cannulated or lag screws for lateral Hoffa fracture seemed to be effective and reliable. The lateral approach had advantages for reduction and fixation of lateral Hoffa fracture during operation.     

Minimally invasive periprosthetic plate osteosynthesis using the locking attachment plate

Objective

Stable fixation of periprosthetic or periimplant fractures with an angular stable plate and early weight bearing as tolerated.

Indications

Periprosthetic femur fractures around the hip, Vancouver type B1 or C. Periprosthetic femur and tibia fractures around the knee. Periprosthetic fractures of the humerus. Periimplant fractures after intramedullary nailing.

Contraindications

Loosening of prosthesis. Local infection. Osteitis.

Surgical technique

Preoperative planning is recommended. After minimally invasive fracture reduction and preliminary fixation, submuscular insertion of a large fragment femoral titanium plate or a distal femur plate. The plate is fixed with locking head screws and/or regular cortical screws where possible. If stability is insufficient, one or two locking attachment plates (LAP) are mounted to the femoral plate around the stem of the prosthesis. After fixing the LAP to one of the locking holes of the femoral plate, 3.5 mm screws are used to connect the LAP to the cortical bone and/or cement mantle of the prosthesis.

Postoperative management

Weight bearing as tolerated starting on postoperative day 1 is suggested under supervision of a physiotherapist.

Results

In 6 patients with periprosthetic fractures and 2 patients with periimplant fractures, no surgical complications (e.g., wound infection or bleeding) were observed. The mean time to bony union was 14 weeks. No implant loosening of the locking attachment plate was observed. At the follow-up examination, all patients had reached their prefracture mobility level.     

Plating of metacarpal fractures with locked or nonlocked screws,a biomechanical study: how many cortices are really necessary?

Background

Dorsal plate and screw fixation is a popular choice for metacarpal stabilization. The balance between construct stability and soft tissue dissection remains a surgical dilemma. Historically, six cortices of bone fixation on either side of a fracture were deemed necessary. This study aims to elucidate whether four cortices of locked fixation on either side of the fracture is equivalent to the current gold standard of six cortices of nonlocked fixation on either side of the fracture. If so, less dissection to insert shorter plates with fewer screws could be used to stably fix these fractures.

Methods

With biomechanical testing-grade composite Sawbones, a comminuted metacarpal fracture model was used to test two fixation constructs consisting of a standard dorsal plate and either six bicortical nonlocking screws (three screws per segment) or four bicortical locking screws (two screws per segment). Thirty specimens were tested to failure in cantilever bending and torsion.

Results

There was statistical equivalence between the locking and nonlocking constructs in cantilever bending stiffness, torsional stiffness, maximum bending load, and maximum torque.

Conclusion

The tested metacarpal fracture model had equivalent biomechanical properties when fixed with a standard dorsal plate and either six bicortical nonlocking screws or four bicortical locking screws. By utilizing fewer cortices of fixation, there will be less dissection and less soft tissue stripping during fixation of metacarpal fractures. This will also be of benefit in very proximal or distal fractures as multiple cortices of fixation are often difficult to obtain during stabilization of these challenging fractures.     

Posterior osteosynthesis with monoaxial lateral mass screw-rod system for unstable C1 burst fractures

Background Context

Surgical treatment for unstable atlas fractures has evolved in recent decades from C1-C2 or C0-C2 fusion to motion-preservation techniques of open reduction and internal fixation (ORIF). However, regardless of a transoral or a posterior approach, the reduction is still not satisfactory.

Plate fixation of proximal humerus fractures using the minimally invasive anterolateral delta split approach

Objective

Minimally invasive plate osteosynthesis of proximal humerus fractures via an anterolateral delta split approach.

Indications

All proximal humerus fractures classified as 11-A1-3, 11-B1-2 (B3), and 11-C1-2 (C3) according to the AO/OTA system.

Contraindications

Head split and closed irreducible dislocation type fractures, fractures with primary neurovascular impairment, and fractures in children with open growth plate.

Surgical technique

Beach chair position. Anterolateral delta split approach. Maintain rotator cuff insertions with nonabsorbable sutures. Reduction and K-wire retention of the tuberosities to the head fragment. Establish a tunnel along the anterolateral aspect of the proximal humerus with a blunt instrument (e.g., elevatorium). Attachment of the rotator cuff sutures to the corresponding plate holes of a 5-hole PHILOS? plate. Insertion of the plate underneath the deltoid muscle along the prepared tunnel. Preliminary fixation of the plate to the humerus head. Distal alignment of the plate and preliminary fixation. Reduction of the fracture onto the plate with a cortical screw in the shaft segment. Definitive plate fixation in the shaft and head segment. The nonabsorbable sutures are then tightened onto the plate.

Postoperative management

Immediate guided active exercise is encouraged. Weight bearing is increased according to radiological signs of consolidation.

Results

In a prospective evaluation from 2003?C2006, 29?patients (8?male and 21?female) with a mean age of 64?years (16?C91?years) were analyzed. The mean follow-up time was 12?months (6?C32?months). The operation was accomplished in 75?min (55?C155?min) with an image intensifier time of 160?s (48?C807?s). All fractures healed in a timely manner. The median Constant score reached 78?points (28?C93?points). In one case (3%), clinical evidence of a lesion of the anterior branch of the axillary nerve was found.     

Are Quadrilateral Surface Buttress Plates Comparable to Traditional Forms of Transverse Acetabular Fracture Fixation?

Background

Several construct options exist for transverse acetabular fracture fixation. Accepted techniques use a combination of column plates and lag screws. Quadrilateral surface buttress plates have been introduced as potential fixation options, but as a result of their novelty, biomechanical data regarding their stabilizing effects are nonexistent. Therefore, we aimed to determine if this fixation method confers similar stability to traditional forms of fixation.

Questions/purposes

We biomechanically compared two acetabular fixation plates with quadrilateral surface buttressing with traditional forms of fixation using lag screws and column plates.

Methods

Thirty-five synthetic hemipelves with a transverse transtectal acetabular fracture were allocated to one of five groups: anterior column plate + posterior column lag screw, posterior column plate + anterior column lag screw, anterior and posterior column lag screws only, infrapectineal plate + anterior column plate, and suprapectineal plate alone. Specimens were loaded for 1500 cycles up to 2.5x body weight and stiffness was calculated. Thereafter, constructs were destructively loaded and failure loads were recorded.

Results

After 1500 cycles, final stiffness was not different with the numbers available between the infrapectineal (568 ± 43 N/mm) and suprapectineal groups (602 ± 87 N/mm, p = 0.988). Both quadrilateral plates were significantly stiffer than the posterior column buttress plate with supplemental lag screw fixation group (311 ± 99 N/mm, p < 0.006). No difference in stiffness was identified with the numbers available between the quadrilateral surface plating groups and the lag screw group (423 ± 219 N/mm, p > 0.223). The infrapectineal group failed at the highest loads (5.4 ± 0.6 kN) and this was significant relative to the suprapectineal (4.4 ± 0.3 kN; p = 0.023), lag screw (2.9 ± 0.8 kN; p < 0.001), and anterior buttress plate with posterior column lag screw (4.0 ± 0.6 kN; p = 0.001) groups.

Conclusions

Quadrilateral surface buttress plates spanning the posterior and anterior columns are biomechanically comparable and, in some cases, superior to traditional forms of fixation in this synthetic hemipelvis model.

Clinical Relevance

Quadrilateral surface buttress plates may present a viable alternative for the treatment of transtectal transverse acetabular fractures. Clinical studies are required to fully define the use of this new form of fixation for such fractures when accessed through the anterior intrapelvic approach.     

Transoral approach to extradural non-neoplastic lesions of the craniovertebral junction

Background

The transoral approach allows for an unobstructed anterior view of the craniovertebral junction from the lower clivus to C1 and C2. It can be applied to a heterogeneous spectrum of pathological lesions involving this area including craniovertebral junction malformations, atlanto-axial synovial cysts, pseudoarthrosis following odontoid fractures, selected cases of retro-odontoid pannus, and vertical translocation in rheumatoid patients.

Methods

Microsurgical strategy is dictated by the nature and site of the target lesion. Atlas preservation during transoral approach (atlas-sparing technique) minimizes postoperative instability and is suitable for the majority of extradural non-neoplastic lesions of the craniovertebral junction. The transoral trans-atlas approach allows for a wider exposure of the anterior craniovertebral junction, but at the price of a higher incidence of postoperative instability; it is usually required in patients with severe basilar invagination or irreducible vertical translocation in rheumatoid arthritis.

Conclusions

The transoral corridor is an effective route to approach a variety of anterior extradural lesions of the craniovertebral junction. Tailoring the approach to each specific lesion provides the needed exposure whilst limiting postoperative instability.     

Minimal-invasive Plattenosteosynthese am distalen Tibiaschaft

Objective

Minimally invasive plate osteosynthesis of distal metaphyseal and/or diaphyseal tibial fractures.

Indications

Extraarticular tibial fractures or distal tibial fractures with simple intraarticular components (AO 42 A–C + AO 43 A, C1, C2) of the distal tibia shaft. Closed or open soft tissue conditions, most suitable for closed soft tissue damage Oestern–Tscherne grade I–II.

Contraindications

High degree open fractures, where the plate would not be covered by soft tissue. Comminuted Pilon fractures.

Surgical technique

Closed reduction manually, over the plate or the external fixator/large distractor. Short incision on the medial malleolus. Epiperosteal insertion of the plate anteromedial. Improve reduction stepwise and insertion of screws on each main fragment. Relative stability is achieved by using bridging techniques. Fibula fixation in special cases.

Postoperative management

Mobilization after 1–3?days with toe-touch weight bearing. Full weight bearing after 8–10?weeks. Implant removal optional after 1–2?years in cases of soft tissue irritation.

Results

Uneventful healing with good function was observed in 85% of patients within 4?months. Delayed unions were observed in 5–10% of cases and nonunions or malalignment were observed in 5% of patients. All patients were satisfied with function at the 2-year follow-up.     

Intraoperative evaluation of dorsal screw prominence after polyaxial volar plate fixation of distal radius fractures utilizing the Hoya view: a cadaveric study

Background

The irregular nature of the dorsal surface of the distal radius makes it difficult to detect prominent screws with volar plate fixation for distal radius fractures using standard fluoroscopic images. This study evaluates the accuracy of a new radiographic method, the Hoya view, for the assessment of dorsal cortical screw penetration with volar plate fixation.

Methods

Eight cadaveric upper extremities underwent application of a volar distal radius plate with polyaxial locking screws placed distally. Utilizing a mini C-arm, lateral and Hoya views were obtained with notation of any dorsal cortical screw prominence. Dissection of the cadavers was then performed for direct visualization of screw prominence. The screws were then exchanged sequentially for screws 2-mm longer than their initial measurements with repeated imaging and direct visualization.

Results

The Hoya view revealed that 9.4 % of the screws penetrated the dorsal cortex with an average screw prominence of 1.08 mm (range 0.5–2 mm). None of the six prominent screws were detected with lateral views. With the Hoya view, six of six prominent screws were identified. With locking screws exchanged for screws 2-mm longer, 76.6 % of the screws had violated the dorsal cortex; of these, 24.5 % were detected with lateral imaging versus 100 % with the Hoya view.

Conclusions

This study supports the intraoperative use of the Hoya view to evaluate screw length and dorsal cortical screw penetration in volar plate fixation of distal radius fractures. However, this view may be difficult to obtain in patients with limitations in elbow or shoulder range of motion.     

Evaluation of biomechanical properties of anterior atlantoaxial transarticular locking plate system using three-dimensional finite element analysis

Purpose

To evaluate a new anterior atlantoaxial transarticular locking plate system using finite element analysis.

Methods

Thin-section spiral computed tomography was performed from occiput to C₂ region. A finite element model of an unstable atlantoaxial joint, treated with an anterior atlantoaxial transarticular locking plate system, was compared with the simple anterior atlantoaxial transarticular screw system. Flexion, extension, lateral bending, and axial rotation were imposed on the model. Displacement of the atlantoaxial transarticular screw and stress at the screw–bone interface were observed for the two internal fixation systems.

Results

Screw displacement was less using the anterior atlantoaxial transarticular locking plate system compared to simple anterior atlantoaxial transarticular screw fixation under various conditions, and stability increased especially during flexion and extension.

Conclusions

The anterior atlantoaxial transarticular locking plate system not only provided stronger fixation, but also decreased screw-bearing stress and screw–bone interface stress compared to simple anterior atlantoaxial transarticular screw fixation.     

Posterior bridging osteosynthesis for traumatic sacroiliac joint dislocation: a report of seven cases

Objective

To evaluate the long-term clinical and radiographic results in patients treated for 61C3-2 (OTA class) pelvic ring disruption with a posterior bridging sacroiliac fixation.

Design

Retrospective clinical and radiological study.

Setting

University Hospital.

Patients/participants

Between May 2002 and March 2003, seven patients with sacroiliac dislocation were treated with a technique developed for the treatment of pelvic injuries with vertical and horizontal instability.

Intervention

We applied spino-pelvic fixation techniques, using spine instrumentation, to stabilize an SI dislocation. This technique consists of two 5 mm diameter screws inserted into the S1 pedicle and S2 ala. A 5.5 mm rod joins the 2 sacral screws to two 7 mm screws placed into the posterior iliac crest and secured into the cancellous mass of the posterior ilium . The described technique stabilizes the SI-joint by performing a bridging osteosynthesis instead of the commonly performed iliosacral screw osteosynthesis passing the SI-joint. Symphyseal platting is performed to reduce and stabilize the anterior ring if necessary.

Main outcome measurements

Data were analyzed as follows: pelvic fracture classification; functional outcome; radiographic outcome; Leg length discrapency; and CT scan aspect of the sacroiliac joint.

Results

Associated pelvic injuries were present in all the patients and include symphysis rupture and acetabular fractures. Four of the seven patients had fractures of the lower extremities. Follow-up was available for all patients at an average of 27 months (range, 32–24 months). Neither septic nor cutaneous complications were reported. No loss of post-op reduction and no fixation failure were observed. The functional results noted at the last examination were satisfactory with a mean Majeed score of 93.

Conclusion

In our opinion, this surgical technique may be indicated in Tile type C1.2 (61C3-2 OTA class) pelvic ring disruption. It obviously reaches its limits in sacral fractures. The technique described provides effective control of vertical displacement while providing a certain degree of horizontal mobility to facilitate reduction and osteosynthesis of anterior lesions. The quality of the fixation allowed early weight bearing.     

Biomechanical evaluation of the Facet Wedge: a refined technique for facet fixation

Purpose

Purpose of this paper is to evaluate the primary stability of a new approach for facet fixation the so-called Facet Wedge (FW) in comparison with established posterior fixation techniques like pedicle screws (PS) and translaminar facet screws (TLS) with and without anterior cage interposition.

Methods

Twenty-four monosegmental fresh frozen non-osteoporotic human motion segments (L2–L3 and L4–L5) were tested in a two-arm biomechanical study using a robot-based spine tester. Facet Wedge was compared with pedicle screws and translaminar screws as a stand-alone device and in combination with an anterior fusion cage.

Results

Pedicle screws, FW and translaminar screws could stabilize an intact motion segment effectively. Facet Wedge was comparable to PS for lateral bending, extension and flexion and slightly superior for axial rotation. Facet Wedge showed a superior kinematic capacity compared to translaminar screws.

Conclusions

Facet Wedge offers a novel posterior approach in achieving primary stability in lumbar spinal fixation. The results of the present study showed that the Facet Wedge has a comparable primary stability to pedicle screws and potential advantages over translaminar screws.     

Radiographic and clinical assessment on the accuracy and complications of C1 anterior lateral mass and C2 anterior pedicle screw placement in the TARP-III procedure: a study of 106 patients

Purpose

To investigate the (1) radiographic and clinical accuracy of C1 anterior lateral mass screw (C1ALMS) and C2 anterior pedicle screw (C2APS) placement in the transoral atlantoaxial reduction plate (TARP)-III procedure, (2) screw insertion-associated clinical complications and (3) fusion status between C1 and C2.

Methods

Radiographic and clinical data were obtained from the electronic medical record system. Studies were carried out to assess the accuracy of C1ALMS and C2APS placement, the screw insertion-associated clinical complications and the fusion status between C1 and C2. Placement of the screws was assessed using the modified All India Institute of Medical Sciences outcome-based classification.

Results

Two-hundred and twelve C1ALMS and 207 C2APS in 106 patients were assessed. The ideal accurate rates were 92.0 % (195) and 53.1 % (110), and the acceptable accurate rates were 97.6 % (207) and 87.0 % (180), respectively. One patient died postoperatively due to C2 screw misplacement. There were no symptoms of neurologic and vertebral artery injuries in the rest of the patients. 102 patients (97.1 %) achieved solid fusion between C1 and C2. No instrumentation failure due to delayed union or nonunion was observed.

Conclusion

C1ALMS placement in TARP-III procedures appears to be safe. The cortical breach rate of C2APS is high though clinically the neurovascular complication rate is similar to that of posterior atlantoaxial procedures. Advanced navigation strategies may help improve the accuracy of C2APS placement and decrease potential complications.     

Minimal-invasive Plattenosteosynthese des distalen Femurs

Objective

Minimally invasive stabilization of articular and extra-articular fractures of the distal femur with anatomically preshaped, locking compression plates.

Indications

Distal extra-articular femoral fractures. Distal periprosthetic or periosteosynthetic femoral fractures. Multifragmentary articular fractures of the distal femur.

Contraindications

Local soft tissue infection or osteitis.

Surgical technique

Patient in a supine position on a radiolucent table with both legs draped free. Fractured leg supported with a towel to release traction of the gastrocnemius muscles onto the distal fragment. Reduction and fixation of articular fractures with 3.5?mm lag screws. Indirect reduction of the metaphyseal fracture component and temporary fixation with different instruments (e.g. cerclage) or reduction to the plate with special tools (e.g. collinear reduction clamp). Submuscular epiperiosteal introduction of the plate. Plate fixation through the aiming device. Intraoperative image intensification control to check plate position and reduction with special emphasis on rotation and longitudinal axes.

Postoperative management

Continuous passive motion without range limitations from day 1. Mobilization on crutches with toe-to-tip weight bearing during the first 6 weeks. No full weight loading until osseous consolidation.

Results

Between January 2009 and November 2011, minimally invasive plate osteosynthesis using the minimally invasive cerclage passer or the collinear reduction clamp was performed in 21 patients with 23 distal femoral fractures. None of the patients suffered from postoperative malalignment or malrotation. Mean time to adequate fracture consolidation was 128 days (range 53–470 days).     

Pedicle screw fixation in thoracolumbar and lumbar spine assisted by lateral fluoroscopic imaging: a study to evaluate the accuracy of screw placement

Background

The purpose of this study was to evaluate the accuracy of pedicle screw placement, its advantages, and limitations in posterior instrumentation of thoracolumbar and lumbar burst fractures assisted only by lateral fluoroscopic imaging.

Materials and methods

Pre- and postoperative computerized tomographic (CT) scans of 117 patients with thoracolumbar and lumbar burst fractures, who underwent posterior instrumentation with pedicle screw fixation, were prospectively analyzed. Accuracy of screw placement, reconstruction of the vertebral height, and correction of the kyphotic angle were studied. Position of the pedicle screws were determined, and cortical breach was graded on the postoperative axial CT scans. Percentage of vertebral height reconstruction and kyphotic angle correction were calculated from the postoperative midsagittal CT scans.

Results

Four hundred and sixty-eight pedicle screws in 234 motion segments were included in this study. 427 screws were centrally placed with an accuracy rate of 91.24%. Out of the 41 (8.76%) screws that breached the pedicle wall, 32 (6.84%) screws had violated the medial wall, while 9 (1.92%) screws breached the lateral wall. There were no “air-ball” screws. No screw penetrated the anterior wall. Postoperatively, none of the patients deteriorated neurologically, and no screw required revision. Postoperatively, there was significant restoration of vertebral height and correction of kyphosis (P < 0.05).

Conclusion

Pedicle fixation performed on a Relton-Hall frame is relatively simple and, when performed carefully using only lateral fluoroscopic imaging, has a lower potential for complications due to cortical breach.

     

Treatment for displaced proximal humerus fractures: comparison of interlocking plate fixation versus minimal invasive techniques

Background and purpose

The functional results and the complications following interlocking plate fixation of displaced proximal humerus fractures should be evaluated and compared with those following minimal invasive fixation techniques.

Patients and methods

Fifty patients (30 women, 20 men, mean age 62.7 (18–91) years) were treated for a displaced proximal humerus fracture using an interlocking plate fixation (PHILOS^®) between 2003 and 2004. The mean follow-up time was 12 (9–36) months. Functional and radiographic results (Constant-Murley and Neer scores) were analyzed and compared with an equivalent historical control group of 53 patients operated for the same fracture types using minimal invasive techniques (K-wires and/or cannulated screws) between 1995 and 1997. According to the OTA/AO classification, there were 15 type A, 18 type B, and 17 type C fractures in the plate fixation group, and 23, 25, and 5 of these types in the control group, respectively.

Results

The mean Neer score was 85.9, the mean Constant-Murley score 84, whereas 82.4 and 75.4 for the control group, respectively. Good and excellent results were seen in 78 %, whereas in 70 % in the control group. The results were dependent upon the fracture’s type, sex, and patient’s age. Complications were seen in 9 patients, whereas in 16 patients in the control group.

Interpretation

Using an interlocking plate, the indication of fixation of displaced proximal humerus fractures had been expanded to type C fractures. The implant failure rate can be reduced. The functional results achieved are better compared with those following minimal invasive techniques.     

Transoral anterior revision surgeries for basilar invagination with irreducible atlantoaxial dislocation after posterior decompression: a retrospective study of 30 cases

Purpose

To report the surgical techniques and clinical results of one-stage transoral anterior revision surgeries for basilar invagination (BI) with atlantoaxial dislocation (AAD) after posterior decompression.

Methods

From September 2008 to June 2012, 30 patients (16 men and 14 women) who had BI with irreducible atlantoaxial dislocation (IAAD) after posterior decompression underwent anterior revision surgeries in our department. Dynamic cervical radiographs, computed tomographic scans and magnetic resonance imaging were obtained pre- and postoperatively to assess the degree of AAD and ventral compression on the cervical cord. The JOA scoring system was used to evaluate the neurological status. The revision surgeries were conducted by anterior approach, using the transoral atlantoaxial reduction plate (TARP) system.

Results

The revision surgeries were successfully performed in all of the cases. The average follow-up duration was 16 months (range 6–39 months). For all of the cases, complete or more than 50 % reduction and decompression of C1–C2 were achieved. The cervicomedullary angle was improved by an average of 32.9°. Bone fusion was achieved within 3–6 months in all of the cases. Clinical symptoms were alleviated in 29 patients (96.7 %) and stabilised in 1 patient (3.3 %). No patients have developed recurrent or progressive atlantoaxial instability so far.

Conclusion

Anterior revision surgeries using the TARP system achieved reduction, decompression and fixation of C1–C2 in one stage for BI with IAAD. This technique offers an effective, simple and safe method for the revision of such cases after posterior decompression.