Minimally invasive anterior transarticular screw fixation and microendoscopic bone graft for atlantoaxial instability

Purpose

Even though transarticular screw (TAS) fixation has been commonly used for posterior C1–C2 arthrodesis in both traumatic and non-traumatic lesions, anterior TAS fixation C1–2 is a less invasive technique as compared with posterior TAS which produces significant soft tissue injury, and there were few reports on percutaneous anterior TAS fixation and microendoscopic bone graft for atlantoaxial instability. The goals of our study were to describe and evaluate a new technique for anterior TAS fixation of the atlantoaxial joints for traumatic atlantoaxial instability by analyzing radiographic and clinical outcomes.

Methods

This was a retrospective study of seven consecutive patients with C1–C2 instability due to upper cervical injury treated by a minimally invasive procedure from May 2007 to August 2009. Bilateral anterior TAS were inserted by the percutaneous approach under Iso-C3D fluoroscopic control. The atlantoaxial joint space was prepared for morselized autogenous bone graft under microendoscopy. The data for analysis included time after the injuries, operating time, intraoperative blood loss, X-ray exposure time, clinical results, and complications. Radiographic evaluation included the assessment of atlantoaxial fusion rate and placement of TAS. Bone fusion of the atlantoaxial joints was assessed by flexion extension lateral radiographs and 1-mm thin-slice computed tomography images as radiographic results. Clinical assessment was done by analyzing the recovery state of clinical presentation from the preoperative period to the last follow-up and by evaluating complications.

Results

A total of 14 screws were placed correctly. The atlantoaxial solid fusion without screw failure was confirmed by CT scan in seven cases after a mean follow-up of 27.5 months (range 18–45 months). All patients with associated clinical presentation made a recovery without neurologic sequelae. Postoperative dysphagia occurred and disappeared in two cases within 5 days after surgery. There were no other complications during the follow-up period.

Conclusions

Percutaneous anterior TAS fixation and microendoscopic bone graft could be an option for achieving C1–C2 stabilization with several potential advantages such as less tissue trauma and better accuracy. Bilateral TAS fixation and morselized autograft affords effective fixation and solid fusion by a minimally invasive approach.     

Subaxial subluxation after atlantoaxial transarticular screw fixation in rheumatoid patients

The most common cervical abnormality associated with rheumatoid arthritis (RA) is atlantoaxial subluxation, and atlantoaxial transarticular screw fixation has proved to be one of the most reliable, stable fixation techniques for treating atlantoaxial subluxation. Following C1–C2 fixation, however, subaxial subluxation reportedly can bring about neurological deterioration and require secondary operative interventions. Rheumatoid patients appear to have a higher risk, but there has been no systematic comparison between rheumatoid and non-rheumatoid patients. Contributing radiological factors to the subluxation have also not been evaluated. The objective of this study was to evaluate subaxial subluxation after atlantoaxial transarticular screw fixation in patients with and without RA and to find contributing factors. Forty-three patients who submitted to atlantoaxial transarticular screw fixation without any concomitant operation were followed up for more than 1 year. Subaxial subluxation and related radiological factors were evaluated by functional X-ray measurements. Statistical analyses showed that aggravations of subluxation of 2.5 mm or greater were more likely to occur in RA patients than in non-RA patients over an average of 4.2 years of follow-up, and postoperative subluxation occurred in the anterior direction in the upper cervical spine. X-ray evaluations revealed that such patients had a significantly smaller postoperative C2–C7 angle, and that the postoperative AA angle correlated negatively with this. Furthermore, anterior subluxation aggravation was significantly correlated with the perioperative atlantoaxial and C2–C7 angle changes, and these two changes were strongly correlated to each other. In conclusion, after atlantoaxial transarticular screw fixation, rheumatoid patients have a greater risk of developing subaxial subluxations. The increase of the atlantoaxial angel at the operation can lead to a decrease in the C2–C7 angle, followed by anterior subluxation of the upper cervical spine and possibly neurological deterioration.     

Reduction techniques in the management of atlantoaxial subluxation

Background:

The traditional approach to atlantoaxial subluxation which is irreducible after traction is transoral decompression and reduction or odontoid excision and posterior fixation. Transoral approach is associated with comorbidities. However using a posterior approach a combination of atlantoaxial joint space release and a variety of manipulation procedures, optimal or near optimal reduction can be achieved. We analysed our results in this study based on above procedure.

Materials and Methods:

66 cases treated over a 5 year period were evaluated retrospectively. Three cases treated by occipito cervical fusion were not included in the study. The remaining 63 cases were classified into three types. All except two cases were subjected to primary posterior C1-C2 joint space dissection and release followed by on table manipulation which was tailored to treat the type of atlantoaxial subluxation. Optimal or near optimal reduction was possible in all cases. An anterior transoral decompression was needed only in two cases where a bony growth (callus) between the C1 anterior arch and the odontoid precluded reduction by posterior manipulation. All cases then underwent posterior fusion and fixation procedures. Patients were neurologically and radiologically evaluated at regular followups to assess fusion and stability for a minimum period of 6 months.

Results:

Of the 63 cases who underwent posterior manipulation, 49 cases achieved optimum reduction and the remaining 14 cases showed near optimal reduction. Two cases expired in the postoperative period. None of the remaining cases showed neurological worsening after the procedure. Evaluation at 6 months after surgery revealed good stability and fusion in all except three cases.

Conclusion:

Atlantoaxial joint release and manipulation can be used to achieve reduction in most cases of atlantoaxial subluxation, obivating the need of transoral odontoid excision.     

Does atlantoaxial dislocation influence the subaxial cervical spine?

Introduction

Previous studies have reported that the alignments of the occipital-cervical and subaxial spine were closely interrelated in asymptomatic individuals; however, none have focused on a population with atlantoaxial dislocation.

Material and methods

From 2007 to 2011, 298 patients with atlantoaxial dislocation and atlas occipitalization were studied. Angles formed between Occiput-C2 and C2–C7 were measured. The relationship between the alignment of the occipital-cervical junction and the subaxial cervical spine was evaluated.

Results

The range of values for the angles measured was as followed: the Occiput-C2 angles were −35.2° to 44.8°, and the C2–C7 angles were −17.4° to 77.8°. Statistically significant negative correlations were observed between the Occiput-C2 and C2–C7 angles.

Conclusion

Anterior dislocations of the atlas are associated with diminished lordosis or even kyphosis of the occipital-cervical junction, and result in compensatory hyperlordosis of the subaxial cervical spine, collectively presenting as a “swan neck” deformity. Atlantoaxial dislocation may influence the global cervical alignment.     

Short-term results of musculotendinous release for paralytic hip subluxation in children with spastic cerebral palsy

INTRODUCTION

Children with paralytic hip subluxation secondary to spastic cerebral palsy were treated with a standard protocol that depended on early detection of the subluxation using clinical examination detecting limited range of hip abduction of ≤ 30° and anteroposterior pelvis radiographs detecting subluxation ≥ 33% migration as indications.

PATIENTS AND METHODS

Patients underwent open adductor longus, proximal gracilis and proximal rectus femoris myotomy, and iliopsoas lengthening with immediate postoperative immobilisation in abduction bar for 3 weeks followed by physiotherapy. The protocol was applied to 50 children with a mean age of 3.6 years with 100 hips surgically corrected. Of these hips initially, 52% were mildly subluxated with ≤ 33% migration, 42% were moderately subluxated with > 33–66% migration, and 6% were severely subluxated with > 66% migration.

RESULTS

At a final postoperative follow-up of at least 24 months, 22% of these hips were classified as excellent with full containment and no migration, 54% were good with < 20% migration, and 24% were fair with 20–25% migration. No poor result with > 25% migration was obtained. No child developed an abduction contracture or wide-based gait that required treatment.

CONCLUSIONS

Early detection and application of this treatment algorithm for children with spastic hip disease should have satisfactory outcomes. Longer follow-up will be required to determine how many children will need bony reconstruction to maintain stable containment of hips at maturity.     

Comparison of Kirschner wires and AO cannulated screw internal fixation for displaced lateral humeral condyle fracture in children

Purpose

This retrospective study compares Kirschner wires versus 3.5-mm diameter AO cannulated screw internal fixation in treatment for the displaced lateral humeral condyle fractures.

Methods

The study included 62 patients (42 boys, 20 girls; mean age 6.93 years; age range two to 14 years) with displaced lateral humeral condyle fractures. All patients were treated by open reduction and Kirschner wires or cannulated screw fixation. The clinical outcomes were evaluated according to the criteria of Hardacre et al. The mean follow-up period was 39.4 months (range 21–95 months).

Results

There was no statistically significant difference in clinical outcome between these two groups (P > 0.05). Five patients (16.7%) developed skin infection around K-wires, while no infection occurred in fracture with screws. An obvious lateral prominence occurred in 11 (36.7%) patients with K-wires and four (12.5%) patients with screws. Nine (30%) patients with K-wires and two (6.3%) patients with screws had a lack of 10° of extension of the elbow compared with the other side.

Conclusion

Both K-wires and cannulated screw fixation are effective in treatment for displaced lateral humeral condyle fracture. K-wires can pass through the ossific nucleus of capitulum without damaging it, but a longer period of external fixation and local skin care will be required. The screws can reduce the possibility of lateral prominence and promote the function of elbow by continuously stabilising the fracture, but a second operation is need for screw removal.     

Odontoid fractures: A retrospective analysis of 53 cases

Background:

The management of odontoid fracture has evolved but controversy persists as to the best method for Type II odontoid fractures with or without atlantoaxial (AA) instability. The anterior odontoid screw fixation can be associated with significant morbidity while delayed odontoid screw fixation has shown to be associated with reasonable good fusion rates. We conducted a retrospective analysis to evaluate the outcome of a trial of conservative management in type II odontoid fractures without atlantoaxial instability (Group A) followed by delayed odontoid screw fixation in cases in which fusion was not achieved by conservative treatment. The outcome of type II odontoid fracture with AA subluxation (Group B) was also analysed where closed reduction on traction could be achieved and in those atlantoaxial subluxations that were irreducible an intraoperative reduction was done.

Materials and Methods:

A retrospective evaluation of 53 cases of odontoid fractures treated over a 9-year period is being reported. All odontoid fractures without AA instability (n=29) were initially managed conservatively. Three patients who did not achieve union with conservative management were treated with delayed anterior screw fixation. Twenty-four cases of odontoid fractures were associated with AA instability; 17 of them could be reduced with skeletal traction and were managed with posterior fusion and fixation. Of the seven cases that were irreducible, the initial three cases were treated by odontoid excision followed by posterior fusion and fixation; however, in the later four cases, intra operative reduction was achieved by a manipulation procedure, and posterior fusion and fixation was performed.

Results:

Twenty-six of 29 cases of odontoid fracture without AA instability achieved fracture union with conservative management whereas the remaining three patients achieved union following delayed anterior odontoid screw fixation. 17 out of 24 odontoid fracture with atlantoaxial dislocation could be reduced on traction and these patients underwent posterior fusion and fixation. Optimal or near optimal reduction was achieved by on table manipulation in four cases which were irreducible with skeletal traction. Atlantoaxial stability was achieved in all cases. All cases were noted to be stable on evaluation with x-rays at six months.

Conclusions:

The initial conservative management and use of odontoid screw fixation only in cases where conservative management for 6–12 weeks has failed to provide fracture union have shown good outcome in type II odontoid fracture without AA instability rates. Intraoperative manipulation and reduction in patients where AA subluxation failed to reduce on skeletal traction followed by posterior fusion obviates the need for transoral odontoid excision.     

Complications and associated risk factors at screw removal in slipped capital femoral epiphysis treated by cannulated stainless steel screws

Purpose

The aim of our study is to report our complication rate and analyze the associated risk factors when removing cannulated stainless steel screws for SCFE fixation.

Methods

This was a multicenter retrospective study of patients who underwent removal of cannulated stainless steel screws after a mean time of 2.03 years of implantation. Thirty-two patients were included (38 hips) with a mean of 13.7 years of age during screw removal surgery. The mean post-removal follow up time was 1.6 years. In all cases the removal of screws was done systematically. Demographic data, possible risk factors related to removal failure, as well as post-removal complications such as post-removal fractures, infections and scar issues were recorded.

Results

A removal failure rate of 15.79 % (6/38) was found. The removal surgical time was longer than the initial fixation time but without statistical significance (70.78 vs 61.84 m, p = 0.196). However, the duration of screw implantation (r²: 7.09; IC: 1.12–13.06) and screw head bony coverage (r²: 21.32; IC: 5.58–37.06) were both related to this prolonged time. Multivariant analysis revealed that a fully threaded cannulated screw had the lowest removal failure risk (OR: 0.3; IC: 0.14–0.61). There were no postremoval complications recorded.

Conclusions

We recommend to use full threaded cannulated stainless steel screws and to perform the procedure as soon as the physis are closed to decrease the surgical time. It is a safe procedure based on a low rate of complications such as post-removal fractures, infection and scar issues.     

Age-related changes in osseous anatomy, alignment, and range of motion of the cervical spine. Part I: Radiographic data from over 1,200 asymptomatic subjects

Purpose

This study aimed to establish radiographic standard values for cervical spine morphometry, alignment, and range of motion (ROM) in both male and female in each decade of life between the 3rd and 8th and to elucidate these age-related changes.

Methods

A total of 1,230 asymptomatic volunteers underwent anteroposterior (AP), lateral, flexion, and extension radiography of the cervical spine. There were at least 100 men and 100 women in each decade of life between the 3rd and 8th. AP diameter of the spinal canal, vertebral body, and disc were measured at each level from the 2nd to 7th cervical vertebra (C2–C7). C2–C7 sagittal alignment and ROM during flexion and extension were calculated using a computer digitizer.

Results

The AP diameter of the spinal canal was 15.8 ± 1.5 [mean ± standard deviation (SD)] mm at the mid-C5 level, and 15.5 ± 2.0 mm at the C5/6 disc level. The disc height was 5.8 ± 1.3 mm at the C5/6 level, which was the minimum height, and the maximum height was at the C6/7 level. Both the AP diameter of the spinal canal and disc height decreased gradually with increasing age. The C2–C7 sagittal alignment and total ROM were 13.9 ± 12.3° in lordosis and 55.3 ± 16.0°, respectively. The C2–C7 lordotic angle was 8.0 ± 11.8° in the 3rd decade and increased to 19.7 ± 11.3 in the 8th decade, whereas the C2–C7 ROM was 67.7 ± 17.0° in the 3rd decade and decreased to 45.0 ± 12.5 in the 8th decade. The extension ROM decreased more than the flexion ROM, and lordotic alignment progressed with increasing age. There was a significant difference in C2–C7 alignment and ROM between men and women.

Conclusions

The standard values and age-related changes in cervical anatomy, alignment, and ROM for males and females in each decade between the 3rd and 8th were established. Cervical lordosis in the neutral position develops with aging, while extension ROM decreases gradually. These data will be useful as normal values for the sake of comparison in clinical practice.     

Impact of the tibial slope on range of motion after low-contact-stress,mobile-bearing,total knee arthroplasty

Purpose

The aim of this study was to analyse a possible correlation between the tibial slope and range of motion (ROM) after implantation of the low-contact-stress (LCS), mobile-bearing, total knee arthroplasty (TKA) after a minimum follow-up of ten years.

Methods

Eighty-three TKAs in 66 patients were investigated in this retrospective correlation analysis at a minimum follow up of ten years. Out of these 66 patients, 50 were women (76 %) and 16 (24 %) were men. The average age of these patients at the time of the examination was 76 years [standard deviation (SD) 11 years, range 37–95 years]. A lateral X-ray was taken at follow-up in order to analyse the tibial slope with respect to inter- and intra-observer agreement. ROM was measured and correlated with the tibial slope.

Results

The mean active ROM was 96.1° (SD 18.8) and the mean tibial slope after four measurements was 7.65° (SD 4.23), with substantial inter- and intra-observer agreement. We found no significant correlation between tibial slope and ROM in patients with a minimum follow-up of ten years [correlation 0.196 (p > 0.05) and 0.152, (p > 0.05), respectively].

Conclusions

Alteration of the tibial slope does not significantly influence ROM after implantation of the LCS TKA at a minimum follow-up of ten years. We conclude that the tibial slope is not the primary influencing factor for ROM in patients ten years after primary TKA and believe that it should not substantially be altered during surgery.     

Complications and outcomes of posterior fusion in children with atlantoaxial instability

Introduction

Atlantoaxial instability (AAI) is an uncommon disease in children. Surgical treatment of pediatric patients with AAI poses a challenge to spine surgeons because of the patients’ immature bone quality, extensive anatomical variability, and smaller osseous structures. In this study, the authors report complications and outcomes after posterior fusion in children with AAI.

Methods

The authors reviewed medical records of patients 13 years old and younger with AAI who underwent posterior fusion in the Nagoya Spine Group hospitals, a multicenter cooperative study group, from January 1995 to December 2007. We identified 11 patients who underwent posterior fusion, and analyzed their clinical outcomes and complications. To determine if vertical growth within the construct continued after posterior fusion, in three patients at 5 or more years following occipito-cervical (O-C) fusion, intervertebral disc heights and vertebral heights between the fused and non-fused levels were compared on the final follow-up.

Results

The initial surgeries were C1–C2 fusions in six patients and O-C fusion in five patients. Successful fusion ultimately occurred in all patients, however, the complication rate related to the operations was high (64%). Complications included neurologic deterioration, pedicle fracture with pedicle screw insertion, C1 posterior arch fracture with lateral mass screw insertion, perforation of the skull with a head pin placement, and fusion extension to adjacent vertebrae. Two patients required reoperation. The mean fixed and non-fixed intervertebral disc heights on the final follow-up were 2.6 and 5.3 mm, respectively, showing that the disc height of the fixed level was less than the non-fused level. Each vertebra lengthened similarly between fused and non-fused levels except for C2 which had a lower growth rate than the other vertebrae.

Conclusions

A high complication rate should be anticipated after posterior fusion in children with AAI. Careful consideration should be paid to pediatric patients with AAI treated by screw and/or rod systems. After posterior fusion in pediatric patients, each vertebra continued to grow, in contrast the disc height decreased between fused levels.     

Correlating preoperative imaging with intraoperative fluoroscopy in iliosacral screw placement

Background

Percutaneous iliosacral screw placement can successfully stabilize unstable posterior pelvic ring injuries. Intraoperative fluoroscopic imaging is a vital component needed in safely placing iliosacral screws. Obtaining and appropriately interpreting fluoroscopic views can be challenging in certain clinical scenarios. We report on a series of patients to demonstrate how preoperative computed tomography (CT) imaging can be used to anticipate the appropriate intraoperative inlet and outlet fluoroscopic views.

Materials and methods

24 patients were retrospectively identified with unstable pelvic ring injuries requiring operative fixation using percutaneous iliosacral screws. Utilizing the sagittal reconstructions of the preoperative CT scans, anticipated inlet and outlet angle measurements were calculated. The operative reports were reviewed to determine the angles used intraoperatively. Postoperative CT scans were reviewed for repeat measurements and to determine the location and safety of each screw.

Results

Preoperative CT scans showed an average inlet of 20.5° (7°–37°) and an average outlet of 42.8° (30°–59°). Intraoperative views showed an average inlet of 24.9° (12°–38°) and an average outlet of 42.4° (29°–52°). Postoperative CT scans showed an average inlet of 19.4° (8°–31°) and an average outlet of 43.2° (31°–56°). The average difference from preoperative to intraoperative was 4.4° (−21° to 5°) for the inlet and 0.45° (−9° to 7°) for the outlet. The average difference between the preoperative and postoperative CT was 2.04° (0°–6°) for the inlet and 2.54° (0°–7°) for the outlet.

Conclusion

There is significant anatomic variation of the posterior pelvic ring. The preoperative CT sagittal reconstruction images allow for appropriate preoperative planning for anticipated intraoperative fluoroscopic inlet and outlet views within 5°. Having knowledge of the desired intraoperative views preoperatively prepares the surgeon, aids in efficiently obtaining correct intraoperative views, and ultimately assists in safe iliosacral screw placement.

Level of evidence

IV, Retrospective case series.     

Anatomical study of the cervical nerve roots for posterior foraminotomy: cadaveric study

Background

Anatomical study of the relationship among the cervical nerve roots, intervertebral disc, and lateral mass is important for the neurosurgeon to avoid complications of posterior cervical foraminotomy.

Methods

Six adult cadavers were studied. The muscles of the back of the neck were removed to expose the cervical vertebrae posteriorly from C3 to C7. We measured the length, height, extent, and angulations of the nerve roots from the medial point of the facet (MPF) after a total laminectomy, then after one-half facetectomy. The height, width, anteroposterior diameter of the lateral mass, then the height and anteroposterior diameter of the neural foramen were also measured.

Results

After total laminectomy from C3 to C7, all measures were taken from MPF showed that the mean length of the exposed root was 6.5–8.8 mm while vertical distance was 4–5.4 mm and the horizontal distance was 5.1–7.1 mm. Following a medial one-half facetectomy; the mean length of the exposed root was 8.9–12.3 mm, the vertical distance was 5.5–7.3 mm while the horizontal distance was 7.1–9.8 mm. The mean angulations of the nerve roots were 50.9–53.3º. There was a significant difference after total laminectomy and medial one-half facetectomy.

Conclusion

Anatomic and morphologic study of the cervical nerve roots and their relationships to the lateral mass and the intervertebral disc are useful landmarks to reduce the operative complications of the posterior foraminotomy.     

Risk factors for post-traumatic osteoarthritis of the ankle: an eighteen year follow-up study

Purpose

Long-term studies evaluating risk factors for development of ankle osteoarthritis (OA) following malleolar fractures are sparse.

Methods

We conducted a retrospective cohort study including consecutive patients treated by open reduction and internal fixation for malleolar fracture between January 1988 and December 1997. Perioperative information was obtained retrospectively. Patients were evaluated clinically and radiographically 12–22 years postoperatively. Radiographic ankle OA was determined on standardised radiographs using the Kellgren and Lawrence scale (grade 3–4 = advanced OA). Uni- and multivariate regression analyses were performed to determine risk factors for OA.

Results

During the inclusion period, 373 fractures (372 patients; 9% Weber A, 58% Weber B, 33% Weber C) were operated upon. The mean age at operation was 42.9 years. There were 102 patients seen at follow-up (mean follow-up 17.9 years). Those not available did not differ in demographics and fracture type from those seen. Advanced radiographic OA was present in 37 patients (36.3%). Significant risk factors were: Weber C fracture, associated medial malleolar fracture, fracture-dislocation, increasing body mass index, age 30 years or more and length of time since surgery.

Conclusions

Advanced radiographic OA was common 12–22 years after malleolar fracture. The probability of developing post-traumatic OA among patients having three or more risk factors was 60–70%.     

Sagittal alignment and kinematics at instrumented and adjacent levels after total disc replacement in the cervical spine

Background

The purpose of the study was to report radiological outcomes after total disc replacement (TDR) in the cervical spine through a 24 months follow-up (FU) prospective study with a special focus on sagittal alignment and kinematics at instrumented and adjacent levels.

Materials and methods

Thirty-two patients, who sustained one-level TDR with a ball-and-socket arthroplasty (Discocerv^™ implant, Scient’x/Alphatec Spine, USA) were consecutively included in the study. Clinical (visual analogical scale and neck disability index) and radiological parameters were measured preoperatively and postoperatively at 3/6 months, 1-year and 2-year FU. Sagittal alignment, ranges of motion (ROM) and center of rotations (CORs) were analyzed using specific motion analysis software (Spineview^™, Paris, France). Patients CORs were compared with those of a control group of 39 normal and asymptomatic subjects.

Results

Both local and C3–C7 lordosis significantly increased postoperatively (+8° and +13° at 2 years, respectively). At instrumented level ROM in flexion–extension (FE) was measured to 10.2° preoperatively versus 7.5° at 1 year and 6.1° at 2 years. There were no differences in ROM at adjacent levels between pre and postoperative assessments. When compared with control group and preoperative measurements, we noted postoperative cranial shift of the COR at instrumented level for patients group. In contrast, there was no difference in CORs location at adjacent levels.

Conclusion

Through this prospective study, we observed that cervical lordosis consistently increased after TDR. In addition, although ball-and-socket arthroplasty did not fully restore native segmental kinematics with significant reduction of motion in FE and consistent cranial shift of the COR, no significant changes in terms of ROM and CORs were observed at adjacent levels.     

Acute distal tibiofibular syndesmosis injury: a systematic review of suture-button versus syndesmotic screw repair

Purpose

Recently, a new suture-button fixation device has emerged for the treatment of acute distal tibiofibular syndesmotic injuries and its use is rapidly increasing. The current systematic review was undertaken to compare the biomechanical properties, functional outcome, need for implant removal, and the complication rate of syndesmotic disruptions treated with a suture-button device with the current ''gold standard'', i.e. the syndesmotic screw.

Method

A literature search in the electronic databases of the Cochrane Library, EMbase, Pubmed Medline, and Google Scholar, between January 1st 2000 to December 1st 2011, was conducted to identify studies in which unstable ankle fractures with concomitant distal tibiofibular syndesmotic injury were treated with either a syndesmotic screw or a suture-button device.

Results

A total of six biomechanical studies, seven clinical full-text studies and four abstracts on the TightRope system, and 27 studies on syndesmotic screw or bolt fixation were identified. The AOFAS of 133 patients treated with TightRope was 89.1 points, with an average study follow-up of 19 months. The AOFAS score in studies with 253 patients treated with syndesmotic screws (metallic and absorbable) or bolts was 86.3 points, with an average study follow-up of 42 months. Two studies reported an earlier return to work in the TightRope group. Implant removal was reported in 22 (10%) of 220 patients treated with a TightRope (range, 0–25%), in the screw or bolt group the average was 51.9% of 866 patients (range, 5.8–100%).

Conclusion

The TightRope system has a similar outcome compared with the syndesmotic screw or bolt fixation, but might lead to a quicker return to work. The rate of implant removal is lower than in the syndesmotic screw group. There is currently insufficient evidence on the long-term effects of the TightRope and more uniform outcome reporting is desirable. In addition, there is a need for studies on cost-effectiveness of the treatment of acute distal tibiofibular syndesmotic disruption treated with a suture-button device.     

Deviation analysis of C2 translaminar screw placement assisted by a novel rapid prototyping drill template: a cadaveric study

Purpose

The goal of this study is to evaluate the accuracy of patient-specific CT-based rapid prototype drill templates for C2 translaminar screw insertion.

Methods

Volumetric CT scanning was performed in 32 cadaveric cervical spines. Using computer software, the authors constructed drill templates that fit onto the posterior surface of the C2 vertebrae with drill guides to match the slope of the patient’s lamina. Thirty-two physical templates were created from the computer models using a rapid prototyping machine. The drill templates were used to guide drilling of the lamina and post-operative CT images were obtained. The entry point and direction of the planned and inserted screws were measured and compared.

Results

Sixty-four C2 translaminar screws were placed without violating the cortical bone of a single lamina. The bilateral average transverse angle of intended and actual screw for C2TLS was 56.60 ± 2.22°, 56.38 ± 2.51°, 56.65 ± 2.24°, 56.39 ± 2.45°. The bilateral mean coronal angle of the planned and actual screw for C2TLS was 0°, 0°, −0.07 ± 0.32°, 0.12 ± 0.57°. The average displacement of the entry point of the superior and inferior C2TLS in the x, y, z axis was 0.27 ± 0.85, 0.49 ± 1.46, −0.28 ± 0.69, 0.43 ± 0.88, 0.38 ± 1.51, 0.23 ± 0.64 mm.

Conclusion

The small deviations seen are likely due to human error in the form of small variations in the surgical technique and use of software to design the prototype. This technology improves the safety profile of this fixation technique and should be further studied in clinical applications.