Outcome of single level anterior cervical discectomy and fusion using nano-hydroxyapatite/polyamide-66 cage

Background:

Cages have been widely used for the anterior reconstruction and fusion of cervical spine. Nonmetal cages have become popular due to prominent stress shielding and high rate of subsidence of metallic cages. This study aims to assess fusion with n-HA/PA66 cage following one level anterior cervical discectomy.

Materials and Methods:

Forty seven consecutive patients with radiculopathy or myelopathy underwent single level ACDF using n-HA/PA66 cage. We measured the segmental lordosis and intervertebral disc height on preoperative radiographs and then calculated the loss of segmental lordosis correction and cage subsidence over followup. Fusion status was evaluated on CT scans. Odom criteria, Japanese Orthopedic Association (JOA) and Visual Analog Pain Scales (VAS) scores were used to assess the clinical results. Statistically quantitative data were analyzed while Categorical data by χ² test.

Results:

Mean correction of segmental lordosis from surgery was 6.9 ± 3.0° with a mean loss of correction of 1.7 ± 1.9°. Mean cage subsidence was 1.2 ± 0.6 mm and the rate of cage subsidence (>2 mm) was 2%. The rate of fusion success was 100%. No significant difference was found on clinical or radiographic outcomes between the patients (n=27) who were fused by n-HA/PA66 cage with pure local bone and the ones (n=20) with hybrid bone (local bone associating with bone from iliac crest).

Conclusions:

The n-HA/PA66 cage is a satisfactory reconstructing implant after anterior cervical discectomy, which can effectively promote bone graft fusion and prevent cage subsidence.     

Three- and four-level anterior cervical discectomy and fusion with a PEEK cage and plate construct

Introduction

Three- or four-level anterior cervical discectomy and fusion with autograft and plate fixation have demonstrated relatively good fusion rates and outcomes, but donor site morbidity and the limitations of autograft harvest remain problematic. The purpose of this study is to assess the radiographic and clinical outcomes of three- or four-level anterior cervical discectomy and fusion with a PEEK cage and plate construct.

Methods

This retrospective review included 43 consecutive patients who underwent three- or four-level anterior cervical discectomy and fusion with a PEEK cage and plate construct (three level: 39 cases, four level: 4 cases). The fusion rate, time to fusion, Cobb angle and disc height were assessed radiographically. Clinical outcomes were evaluated with the VAS, NDI, and SF36 scores. Complications were also recorded.

Results

Solid fusion was achieved in all the patients, and mean time to fusion was 13.7 ± 5.1 weeks. The postoperative Cobb angle, lordotic angle, and disc height (5.6°, 10.5° and 3.15 mm, respectively) increased significantly compared to preoperative values (p = 0.038, p = 0.032, and p = 0.0004, respectively), and these improvements were maintained through final follow-up. The postoperative NDI (17.2), VAS (2.8), and SF36 (13.1) scores increased significantly compared to the preoperative scores (p = 0.026, p = 0.0007 and p = 0.041, respectively). Complications included three cases of respiratory difficulty, four cases of dysphagia and one case of hoarseness. There were no cases of donor site morbidity.

Conclusions

Three- or four-level anterior cervical discectomy and fusion with a PEEK cage, and plate construct provide good clinical and radiographic outcomes including high fusion rates, low complication rates, low donor site morbidity, and good maintenance of the lordotic angle and disc height in the treatment of multilevel cervical spondylosis.     

Cage subsidence does not, but cervical lordosis improvement does affect the long-term results of anterior cervical fusion with stand-alone cage for degenerative cervical disc disease: a retrospective study

Objective

Clinical outcomes of the stand-alone cage have been encouraging when used in anterior cervical discectomy and fusion (ACDF), but concerns remain regarding its complications, especially cage subsidence. This retrospective study was undertaken to investigate the long-term radiological and clinical outcomes of the stand-alone titanium cage and to evaluate the incidence of cage subsidence in relation to the clinical outcome in the surgical treatment of degenerative cervical disc disease.

Methods

A total of 57 consecutive patients (68 levels) who underwent ACDF using a titanium box cage for the treatment of cervical radiculopathy and/or myelopathy were reviewed for the radiological and clinical outcomes. They were followed for at least 5 years. Radiographs were obtained before and after surgery, 3 months postoperatively, and at the final follow-up to determine the presence of fusion and cage subsidence. The Cobb angle of C2–C7 and the vertebral bodies adjacent to the treated disc were measured to evaluate the cervical sagittal alignment and local lordosis. The disc height was measured as well. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score for cervical myelopathy, before and after surgery, and at the final follow-up. The recovery rate of JOA score was also calculated. The Visual Analogue Scale (VAS) score of neck and radicular pain were evaluated as well. The fusion rate was 95.6% (65/68) 3 months after surgery.

Results

Successful bone fusion was achieved in all patients at the final follow-up. Cage subsidence occurred in 13 cages (19.1%) at 3-month follow-up; however, there was no relation between fusion and cage subsidence. Cervical and local lordosis improved after surgery, with the improvement preserved at the final follow-up. The preoperative disc height of both subsidence and non-subsidence patients was similar; however, postoperative posterior disc height (PDH) of subsidence group was significantly greater than of non-subsidence group. Significant improvement of the JOA score was noted immediately after surgery and at the final follow-up. There was no significant difference of the recovery rate of JOA score between subsidence and non-subsidence groups. The recovery rate of JOA score was significantly related to the improvement of the C2–C7 Cobb angle. The VAS score regarding neck and radicular pain was significantly improved after surgery and at the final follow-up. There was no significant difference of the neck and radicular pain between both subsidence and non-subsidence groups.

Conclusions

The results suggest that the clinical and radiological outcomes of the stand-alone titanium box cage for the surgical treatment of one- or two-level degenerative cervical disc disease are satisfactory. Cage subsidence does not exert significant impact upon the long-term clinical outcome although it is common for the stand-alone cages. The cervical lordosis may be more important for the long-term clinical outcome than cage subsidence     

Relevance of expandable titanium cage for the treatment of cervical spondylotic myelopathy

Background

In patients with cervical spondylotic myelopathy, ventral disease and loss of physiological cervical lordosis are indications for anterior approach. As bone graft and titanium cage present many drawbacks, expandable titanium cage has been recently introduced for this indication. The authors present the clinical and radiological outcomes in patients undergoing the placement of an expandable cage in the treatment of spondylotic myelopathy with straight or kyphotic cervical spine alignment.

Methods

This was a retrospective review of prospectively collected data. A total of 26 patients underwent cervical corpectomy and reconstruction using an expandable titanium cage and anterior plate between 2005 and 2008. Pain and functional disability were measured using VAS and mJOA preoperatively and at 3 months, 6 months, 1 year and 2 years. Kyphosis was measured using lateral radiographs at the same points of follow-up. Fusion was evaluated on flexion–extension radiographs at 2 years.

Results

The mean VAS improved from 4.2 to 1.7 and the mean mJOA increased from 12.85 to 16.04 at 2 years postoperatively (p < 0.05). The mean kyphosis angle decreased from 17° to 2° at the last follow-up (p < 0.05). The fusion rate was 100 % at 2 years. Three complications were reported including a transient dysphagia, an epidural hematoma and an early hardware migration.

Conclusion

Expandable titanium cage is an effective device, which achieves good clinical and radiological outcomes at a minimum 2-year follow-up.     

Subsidence and Nonunion after Anterior Cervical Interbody Fusion Using a Stand-Alone Polyetheretherketone (PEEK) Cage

Background

The purposes of the present study are to evaluate the subsidence and nonunion that occurred after anterior cervical discectomy and fusion using a stand-alone intervertebral cage and to analyze the risk factors for the complications.

Methods

Thirty-eight patients (47 segments) who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage and an autologous cancellous iliac bone graft from June 2003 to August 2008 were enrolled in this study. The anterior and posterior segmental heights and the distance from the anterior edge of the upper vertebra to the anterior margin of the cage were measured on the plain radiographs. Subsidence was defined as ≥ a 2 mm (minor) or 3 mm (major) decrease of the segmental height at the final follow-up compared to that measured at the immediate postoperative period. Nonunion was evaluated according to the instability being ≥ 2 mm in the interspinous distance on the flexion-extension lateral radiographs.

Results

The anterior and posterior segmental heights decreased from the immediate postoperative period to the final follow-up at 1.33 ± 1.46 mm and 0.81 ± 1.27 mm, respectively. Subsidence ≥ 2 mm and 3 mm were observed in 12 segments (25.5%) and 7 segments (14.9%), respectively. Among the expected risk factors for subsidence, a smaller anteroposterior (AP) diameter (14 mm vs. 12 mm) of cages (p = 0.034; odds ratio [OR], 0.017) and larger intraoperative distraction (p = 0.041; OR, 3.988) had a significantly higher risk of subsidence. Intervertebral nonunion was observed in 7 segments (7/47, 14.9%). Compared with the union group, the nonunion group had a significantly higher ratio of two-level fusion to one-level fusions (p = 0.001).

Conclusions

Anterior cervical fusion using a stand-alone cage with a large AP diameter while preventing anterior intraoperative over-distraction will be helpful to prevent the subsidence of cages. Two-level cervical fusion might require more careful attention for avoiding nonunion.     

Efficacy of multilevel anterior cervical discectomy and fusion versus corpectomy and fusion for multilevel cervical spondylotic myelopathy: a minimum 5-year follow-up study

Purpose

We evaluated radiologic and clinical outcomes to compare the efficacy of anterior cervical discectomy and fusion (ACDF) and anterior corpectomy and fusion (ACCF) for multilevel cervical spondylotic myelopathy (CSM).

Methods

A total of 40 patients who underwent ACDF or ACCF for multilevel CSM were divided into two groups. Group A (n = 25) underwent ACDF and group B (n = 15) ACCF. Clinical outcomes (JOA and VAS scores), perioperative parameters (length of hospital stay, blood loss, operation time), radiological parameters (fusion rate, segmental height, cervical lordosis), and complications were compared.

Results

Both group A and group B demonstrated significant increases in JOA scores and significant decreases in VAS. Patients who underwent ACDF experienced significantly shorter hospital stays (p = 0.031), less blood loss (p = 0.001), and shorter operation times (p = 0.024). Both groups showed significant increases in postoperative cervical lordosis and achieved satisfactory fusion rates (88.0 and 93.3 %, respectively). There were no significant differences in the incidence of complications among the groups.

Conclusions

Both ACDF and ACCF provide satisfactory clinical outcomes and fusion rates for multilevel CSM. However, multilevel ACDF is associated with better radiologic parameters, shorter hospital stays, less blood loss, and shorter operative times.     

颈前路椎管减压植骨融合内固定术中应用钛笼与n-HA/PA66人工椎体的疗效比较

目的比较颈椎病颈前路椎管减压植骨融合内固定术中置入钛笼与置入纳米羟基磷灰石/聚酰胺66(nanohydroxyapatite/polyamide66,n-HA/PA66)人工椎体的疗效。方法回顾性分析自2012-01—2017-02采用颈前路椎管减压植骨融合内固定术治疗的97例颈椎病,50例在术中置入钛笼(钛笼组),47例在术中置入n-HA/PA66人工椎体(人工椎体组),比较2组术后即刻、术后3个月、术后6个月颈椎前凸角度与JOA评分,比较2组术后椎体下沉情况以及末次随访时神经功能改善等级。结果97例均顺利完成手术并获得完整随访,随访时间平均10.4(6~18)个月。末次随访时97例均获得骨性融合。2组术后即刻、术后3个月、术后6个月颈椎前凸角度、JOA评分比较差异无统计学意义(P>0.05)。术后6个月钛笼组6例出现钛笼下沉现象,人工椎体组未出现人工椎体下沉现象。人工椎体组椎体下沉情况较钛笼组优,差异有统计学意义(P<0.05)。2组末次随访时神经功能改善等级比较差异无统计学意义(P>0.05)。结论钛笼与n-HA/PA66人工椎体均能有效重建颈椎的稳定性、改善脊髓功能并获得良好的植骨融合率,n-HA/PA66人工椎体置入后可以获得较低的椎体下沉率。     

Evaluation of a new type of titanium mesh cage versus the traditional titanium mesh cage for single-level, anterior cervical corpectomy and fusion

Study design

A retrospective review of prospectively collected data in an academic institution.

Objective

To evaluate the safety and efficacy of a new type of titanium mesh cage (TMC) in single-level, anterior cervical corpectomy and fusion (ACCF).

Methods

Fifty-eight patients consecutive with cervical spondylotic myelopathy (CSM) from cervical degenerative spondylosis and isolated ossification of the posterior longitudinal ligament were treated with a single-level ACCF using either a new type of TMC (28 patients, group A) or the traditional TMC (30 patients, group B). We evaluated the patients for TMC subsidence, cervical lordosis (C2–C7 Cobb and Cobb of fused segments) and fusion status for a minimum of 30 months postoperatively based on spine radiographs. In addition, neurologic outcomes were evaluated using the Japanese Orthopedic Association (JOA) scores. Neck pain was evaluated using a 10-point visual analog scale (VAS).

Results

The loss of height of the fused segments was less for group A than for group B (0.8 ± 0.3 vs. 2.8 ± 0.4 mm) (p < 0.01); also, there was a lower rate of severe subsidence (≥3 mm) in group A (4 %, 1/28) than in group B (17 %, 5/30) (p < 0.01). There were no differences in the C2–C7 Cobb and Cobb of fused segments between the groups preoperatively or at final follow-up (p > 0.05), but the Cobb of fused segments immediately postoperative were significantly less for group B than for group A (p < 0.01). All patients, however, had successful fusion (100 %, each). Both groups had marked improvement in the JOA score after operation (p < 0.01), with no significant differences in the JOA recovery ratio (p > 0.05). The postoperative VAS neck pain scores for group A were significantly less than that for group B (p < 0.05); severe subsidence was correlated with neck pain.

Conclusions

The new type of TMC provides comparable clinical results and fusion rates with the traditional TMC for patients undergoing single-level corpectomy. The new design TMC decreases postoperative subsidence (compared to the traditional TMC); the unique design of the new type of TMC matches the vertebral endplate morphology which appears to decrease the severity of subsidence-related neck pain in follow-up.     

A radiographic and clinical comparison of reamer–irrigator–aspirator versus iliac crest bone graft in ankle arthrodesis

Purpose

We evaluated radiographic fusion at follow-up and complication rates in patients who had either iliac crest (ICBG) or femoral reamer–irrigator–aspirator (RIA) bone graft for tibiotalar fusion.

Methods

We retrospectively reviewed charts and radiographs of all patients who had a tibiotalar fusion from August 2007 to February 2011. Records were analysed for patient demographics, complications, and clinical symptoms. Radiographs were reviewed in sequential order by two fellowship-trained foot and ankle surgeons and one orthopaedic surgeon who specialises in foot and ankle surgery to determine radiographic fusion at routine follow-up. Patients were contacted to determine current visual analog scores (VAS) at their graft site.

Results

Mean patient age was 49.4 ± 12.1 years in the RIA group and 49.3 ± 15.4 years in the ICBG group (p = .97). Pre-operative characteristics showed no significant differences between groups. The ICBG group had significantly more nonunions than the RIA group (six vs. one, p = 0.04). Two patients in the ICBG had chronic pain at their graft site based on their VAS score; there were none in the RIA group. Radiographic fusion at follow-up was similar between groups, with no significant difference (12.48 ± 3.85 weeks vs.12.21 ± 3.19 weeks, p = .80).

Conclusions

There was a significantly higher nonunion rate in the ICBG group, but both groups had a solid radiographic bony fusion at similar follow-up time points. Our results suggest RIA bone graft is a viable alternative to ICBG for tibiotalar fusion.     

纳米羟基磷灰石/聚酰胺66复合物椎间融合器在山羊颈椎融合中的应用

目的:观察纳米羟基磷灰石/聚酰胺66复合物(n-HA/PA66)椎间融合器在山羊颈椎前路融合中的效果。方法:15只成年雌性山羊随机分成A、B、C组,每组5只,均行经前路C3/4椎间盘切除术,A组椎间置入n-HA/PA66椎间融合器植骨;B组置入钛网植骨;C组采用自体三面皮质髂骨块植骨。分别于术前、术后、术后4周、8周及12周拍X线片观察测量各组手术节段平均椎间高度(disc space height,DSH)、椎间角(intervertebral angle,IVA)及前凸角(lordosis angle,LA);12周时处死动物取颈椎标本进行生物力学测试及组织学检查。结果:术前三组DSH、IVA和LA无显著性差异。术后即刻及术后4周三组间DSH无显著性差异(P0.05);术后8周及12周,A组DSH与B、C组有显著性差异(P0.05);B组和C组差别无显著性(P0.05)。术后即刻及术后4周、8周三组间IVA无显著性差异(P0.05);术后12周,A、B组IVA与C组有显著性差异(P0.05),A组与B组无显著性差异。术后即刻及术后4周、8周三组间LA差异无显著性(P0.05);术后12周,A、B组LA与C组有显著性差异(P0.05),B组与C组无显著性差异。术后12周时,A、B组颈椎标本各向角位移与C组有显著性差异(P0.05);除后伸外A组各向稳定性优于B、C组;平均刚度均强于B、C组;ROM均小于B、C组(P0.05)。A组在植骨区和椎间融合器边缘可见大量成熟的骨小梁组织,材料交界处可见大量纤维骨痂及新生骨形成,骨组织与材料表面已发生嵌合;B组的植骨块与椎体间的新生骨小梁已改建为成熟的骨小梁,部分区域尚可见未完全矿化的类骨质;C组可见较多的纤维骨痂形成,在骨小梁表面有红色的类骨质,部分区域有成熟的骨小梁。结论:n-HA/PA66椎间融合器能有效维持椎间隙高度,促进山羊颈椎前路植骨融合。     

Anterior reconstruction with nano-hydroxyapatite/polyamide-66 cage after thoracic and lumbar corpectomy

Cages are used to regain stability of the anterior spinal column following vertebrectomy, which could prevent significant donor-site morbidity from the iliac autograft harvesting and the risk of disease transmission associated with the allograft. The hollow, porous, cylindrical nanohydroxyapatite/polyamide 66 (n-HA/PA66) cage is a new nonmetallic cage device made by combining nanohydroxyapatite with polyamide 66. Few studies have examined its effectiveness and outcomes over a follow-up >2 years.We retrospectively studied 51 consecutive patients with acute traumatic thoracic or lumbar burst fracture who underwent anterior reconstruction with the n-HA/PA66 cage following single-level corpectomy. Radiologic parameters (radiographs and 3-dimensional computed tomography scans) preoperatively and at 1 week and >2 years postoperatively, as well as clinical outcome parameters (SF-36 scores), were analyzed. Mean kyphosis correction in the segment within the cage was 11.8°±7.1°, and mean loss of correction at last follow-up was 1.9°±2.1°. Osseous fusion was achieved in 90.2% of patients, and severe cage subsidence (settling >2 mm) was observed in 19.6% of patients at final follow-up. Significant differences were found in 7 of 8 health dimensions of the SF-36 between neurologically intact patients and neurologically injured patients. Our clinical results indicate that the n-HA/PA66 cage is an effective device for reconstruction after anterior thoracic and lumbar vertebral resection, resulting in a high rate of successful osseous fusion and a low proportion of severe cage subsidence.     

Failed less invasive lumbar spine surgery as a predictor of subsequent fusion outcomes

Purpose

It is not uncommon for patients to undergo less invasive spine surgery (LISS) prior to succumbing to lumbar fusion; however, the effect of failed LISS on subsequent fusion outcomes is relatively unknown. The aim of this study was to test the hypothesis that patients who suffered failed LISS would afford inferior subsequent fusion outcomes when compared to patients who did not have prior LISS.

Methods

After IRB approval, registry from a spine surgeon was queried for consecutive patients who underwent fusion for intractable low back pain. The 47 qualifying patients were enrolled and split into two groups based upon a history for prior LISS: a prior surgery group (PSG) and a non-prior surgery group (nPSG).

Results

Typical postoperative outcome questionnaires, which were available in 80.9 % of the patients (38/47) at an average time point of 40.4 months (range, 13.5–66.1 months), were comparatively analysed and failed to demonstrate significant difference between the groups, e.g. PSG v. nPSG: ODI—14.6 ± 10.9 vs. 17.2 ± 19.4 (P = 0.60); SF12-PCS—10.9 ± 11.0 vs. 8.7 ± 12.4 (p = 0.59); bNRS—3.0 (range −2–7) vs. 2.0 (range −3–8) (p = 0.91). Patient satisfaction, return to work rates, peri-operative complications, success of fusion and rate of revision surgery were also not different.

Conclusions

Although limited by size and retrospective design, the results of this rare investigation suggest that patients who experience a failed LISS prior to undergoing fusion will not suffer inferior fusion outcomes when compared to patients who did not undergo prior LISS.     

Long-term survival of the uncemented Balgrist total hip replacement cup

Purpose

The purpose of this study was to evaluate the long-term clinical and radiographic outcomes of the Balgrist total hip replacement cup.

Methods

We report the results of a retrospective review of 195 total hip prostheses with Balgrist cup implanted in 178 patients. There were 59 men and 119 women with a mean age at surgery of 52.3 years (range, 19–72). Cox regression was used to determine the influence of independent variables on the survivorship of the prosthesis.

Results

There were 117 (66 %) of 178 patients, and 131 (67 %) of 195 hips available for assessment at a mean follow-up of 17.4 years. A total of 21 patients (22 hips) were lost from follow-up (12 %). A total of 25 patients (27 hips) required some type of re-operation during the follow-up period. Eight of 27 re-operations (30 %) were directly caused by the Balgrist cup failure due to fatigue fracture of the metallic shell (n = 5; 19 %), polyethylene wear (n = 2; 7 %) and aseptic loosening (n = 1; 4 %). The mean polyethylene wear rate was 0.068 mm/year (range, 0.008–0.230; SD = 0.043). The risk of re-operation for any reason was decreased with dysplastic hip as a primary diagnosis (hazard ratio; HR = 0.250; 95 % CI 0.086–0.725) and with greater age at the time of surgery (HR = 0.923; 95 % CI 0.880–0.969). The 19-year survivorship with re-operation for any reason was 75.6 % (95 % CI 67.0–84.2). The 19-year survivorship with re-operation for the Balgrist cup failure was 90.5 % (95 % CI 83.4–97.6).

Conclusions

The Balgrist cup continues to provide excellent clinical and radiological outcomes. This is associated at least in part with a low polyethylene wear rate. The main reason for the Balgrist cup failure is fatigue fracture of the metallic shell.     

Magnetic Resonance Imaging is not suitable for interpretation of meniscal status ten years after arthroscopic repair

Purpose

The purpose of this study was to assess the MRI features of the all-inside repaired meniscus in the long-term.

Methods

Among 27 consecutive all-inside arthroscopic meniscal repairs, 23 patients aged 25 ± 5 years at the time of surgery were reviewed at a median follow-up of 10 ± 1 years. Retrospective clinical examinations and imaging assessments using a 1.5-T MRI after all-inside arthroscopic meniscal repair were conducted.

Results

At follow-up, Lysholm and IKDC averaged 89 ± 11 and 95 ± 8, respectively. MRI examinations revealed no meniscal signal alteration in three patients (13 %), a vertical signal located in the previously torn area in seven (30 %), a horizontal grade 3 in nine (39 %), and a complex tear (grade 4) in four (17.5 %). There were no differences between medial and lateral menisci (p = 0.15), stable and stabilised knees (p = 0.56).

Conclusions

Several abnormal vertical and/or horizontal hypersignals are still present on MRI examination ten years after arthroscopic all-inside meniscal repair. The appearance of early signs of osteoarthritis is rare, suggesting a chondroprotective effect of the repaired meniscus.     

Efficacy of PEEK Cages and Plate Augmentation in Three-Level Anterior Cervical Fusion of Elderly Patients

Background

To evaluate the clinical efficacy of three-level anterior cervical arthrodesis with polyethyletherketone (PEEK) cages and plate fixation for aged and osteoporotic patients with degenerative cervical spinal disorders.

Methods

Twenty one patients, who had undergone three-level anterior cervical arthrodesis with a cage and plate construct for degenerative cervical spinal disorder from November 2001 to April 2007 and were followed up for at least two years, were enrolled in this study. The mean age was 71.7 years and the mean T-score using the bone mineral density was -2.8 SD. The fusion rate, change in cervical lordosis, adjacent segment degeneration were analyzed by plain radiographs and computed tomography, and the complications were assessed by the medical records. The clinical outcomes were analyzed using the SF-36 physical composite score (PCS) and neck disability index (NDI).

Results

Radiological fusion was observed at a mean of 12.3 weeks (range, 10 to 15 weeks) after surgery. The average angle of cervical lordosis was 5° preoperatively, 17.6° postoperatively and 16.5° at the last follow-up. Degenerative changes in the adjacent segments occurred in 3 patients (14.3%), but revision surgery was unnecessary. In terms of instrument-related complications, there was cage subsidence in 5 patients (23.8%) with an average of 2.8 mm, and loosening of the plate and screw occurred in 3 patients (14.3%) but there were no clinical problems. The SF-36 PCS before surgery, second postoperative week and at the last follow-up was 29.5, 43.1, and 66.2, respectively. The respective NDI was 55.3, 24.6, and 15.9.

Conclusions

For aged and osteoporotic patients with degenerative cervical spinal disorders, three-level anterior cervical arthrodesis with PEEK cages and plate fixation reduced the pseudarthrosis and adjacent segment degeneration and improved the clinical outcomes. This method is considered to be a relatively safe and effective treatment modality.     

Long-term follow-up and metal ion trend of patients with metal-on-metal total hip arthroplasty

Purpose

Long-term studies are required to support the use of metal-on-metal (MoM) bearings in total hip arthroplasty (THA) given the concern about systemic metal ion release and reports of adverse local soft tissue reactions. The purpose of this study was to report the seven to 13-year clinical, radiographic, and metal ion results in patients following MoM THA.

Methods

We studied 163 prostheses after second-generation MoM THA between July 1997 and November 2003. Cobalt and chromium metal ions were collected using whole and analysed by inductively-coupled plasma-mass spectrometry.

Results

The mean follow-up was 8.87 years (range, 7–13 years). Four hips (2.5 %) were revised. The Kaplan-Meier survivorship was 91.3 % for revision for all causes, and 97.5 % when excluding the hips revised for a manufacturer’s defect. Median whole blood cobalt levels peaked at a value of 2.87 μg/L at four years (p < 0.0001 vs. pre-operative) and subsequently decreased to 2.0 μg/L after nine years (p = 0.002 vs. four years). Median chromium levels maximally increased up to 0.75 μg/L after five years (p < 0.0001 vs. pre-operative) and tended to decrease thereafter to values of 0.56 μg/L after seven years.

Conclusions

This seven to 13-year follow-up study indicates that the clinical and radiological results following MoM THA are satisfactory with low revision rates. Cobalt and chromium ion levels peaked at four and five years, respectively, and gradually decreased thereafter.     

Subsidence of a cementless femoral component influenced by body weight and body mass index

Purpose

This trial was designed to evaluate the impact of physical characteristics such as body mass index, body weight and height on distal stem migration of a cementless femoral component, as the influence of obesity on the outcome of THA is still debated in literature and conflicting results have been found.

Methods

In this retrospective cohort study, migration patterns for 102 implants were analysed using the Einzel-Bild-Roentgen-Analyse (EBRA-FCA, femoral component analysis). In all cases the Vision 2000 stem was implanted and combined with the Duraloc acetabular component (DePuy, Warsaw, Indiana).

Results

The mean follow-up was 93 months. EBRA-FCA evaluations revealed a mean subsidence of 1.38 mm after two years, 2.06 mm after five and 2.24 mm after seven years. Five stems loosened aseptically. Correlation between increased migration over the whole period and aseptic loosening was highly significant (p < 0.001). Surgical technique had a significant influence on migration and stem stability (p = 0.002) but physical patient characteristics such as body weight over 75 kg and height over 165 cm also significantly influenced stem subsidence towards progressive migration (p = 0.001, p < 0.001). However, a high BMI did not trigger progressive stem migration (p = 0.87). Being of the male gender raised the odds for increased migration (p = 0.03).

Conclusion

Physical characteristics such as body weight and height showed significant influence on migration patterns of this cementless femoral component. The operating surgeon should be aware that body weight above 75 kg and height over 165 cm may trigger increased stem migration and the surgeon should aim to fit these prostheses as tightly as possible. However this study demonstrates that a high BMI does not trigger progressive stem migration. Further investigations are needed to confirm our findings.     

Early Results of Sacro–Iliac Joint Fixation Following Long Fusion to the Sacrum in Adult Spine Deformity

Background

The sacro–iliac joint (SIJ) is the largest joint in the human body. When the lumbar spine is fused to the sacrum, motion across the SIJ is increased, leading to increased degeneration of the SIJ. Degeneration can become symptomatic in up to 75% of the cases when a long lumbar fusion ends with a sacral fixation. If medical treatments fail, patients can undergo surgical fixation of the SIJ.

Questions/Purposes

This study reports the results of short-term complications, length of stay, and clinical as well as radiographic outcomes of patients undergoing percutaneous SIJ fixation for SIJ pain following long fusions to the sacrum for adult scoliosis.

Methods

A retrospective review of all the patients who underwent a percutaneous fixation of the SIJ after corrective scoliosis surgery was performed in a single specialized scoliosis center between the years 2011–2013. Ten SIJ fusions were performed in six patients who failed conservative care for SIJ arthritis. Average age was 50 (range 25–60 years). The patients were 15.3 years in average after the original surgical procedure (range 4–25 years). Average post-operative follow-up was 10.25 months (range 15–4 months). The medical charts of the patients were reviewed for hospital stay, complications, pre- and post-operative pain, quality of life, and satisfaction with surgery using the visual analogues score (VAS), Scoliosis Research Society (SRS)22 and Oswestry Disability Index (ODI) questionnaires. Images were reviewed for fixation of the SIJ, fusion, and deviation of the implants from the SIJ.

Results

There were no complications in surgery or post-operatively. Discharge was on post-operative day 2 (range 1–4 days). Leg VAS score improved from 6.5 to 2.0 (P < 0.005; minimal clinically important difference (MCID) 1.6). Back VAS score decreased from 7.83 to 2.67 mm (P < 0.005; MCID 1.2). ODI scores dropped from 22.2 to 10.5 (P = 0.0005; MCID 12.4). SRS22 scores increased from 2.93 to 3.65 (P = 0.035; MCID 0.2) with the largest increases in the pain, function, and satisfaction domains of the questionnaires.

Conclusion

Fixation of the SIJ in patients that fail conservative care for SIJ arthritis after long fusions ending in the sacrum provides a reduction in back pain and improved quality of life in the short and medium range follow-up period.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-013-9374-4) contains supplementary material, which is available to authorized users.     

Disability and pain after cortisone versus placebo injection for trapeziometacarpal arthrosis and de Quervain syndrome

Background

This study tested the null hypothesis that type of injection (corticosteroid vs. placebo) is not a predictor of arm-specific disability as measured with the Disabilities of Arm, Shoulder and Hand questionnaire 1 to 3 months after injection of dexamethasone or placebo for treatment of trapeziometacarpal (TMC) arthrosis or de Quervain syndrome. Secondly, we tested if type of injection was a predictor of pain intensity.

Methods

Thirty-six English-speaking adults with TMC arthrosis or de Quervain syndrome were randomized for a dexamethasone or a placebo injection. At time of the injection, patients completed a demographic data sheet and validated questionnaires assessing arm-specific disability, pain intensity, depressive symptoms, pain catastrophizing, and patient’s health-related beliefs. At an average of 1.4 ± 0.42 months (range, 0.79–2.5 months) after the injection, patients completed questionnaires regarding arm-specific disability, pain, and treatment satisfaction. Grip and pinch strength measurements were measured at both time points. Bivariable and multivariable analyses assessed predictors of arm-specific disability and pain intensity at follow-up.

Results

Type of injection was not a predictor of arm-specific disability or pain intensity 1 to 3 months after injection. The best model both for arm-specific disability and pain intensity at follow-up included pain catastrophizing and explained 18 % and 33 % of the variability, respectively.

Conclusions

Catastrophic thinking was a better predictor of both of arm-specific disability and pain intensity than diagnosis or type of injection (steroid vs. placebo) 1to 3 months after an injection.     

Anterior C3 corpectomy and fusion for complex Hangman’s fractures

Purpose

The aim of this study was to assess the effectiveness and feasibility of anterior C3 corpectomy and fusion with screw-plate fixation of C2–4 for the treatment of Hangman’s fracture in which spinal cord compression comes from the posterosuperior part of C3 vertebral body and the intervertebral disc injury at the C2–3 level.

Methods

From August 2000 to December 2005, 11 patients (eight males and three females) with traumatic spondylolisthesis of the axis underwent the above surgery. Neurological status was evaluated by the Japanese Orthopaedic Association Score (JOA score). The fusion of the graft, healing of the fracture, and range of motion of the whole cervical spine were examined according to X-ray imaging.

Results

No patient received blood transfusion. There was no deterioration of the neurological function in any case postoperatively. The mean JOA score was significantly improved from 9.1 ± 2.3 preoperatively to 14.8 ± 1.2 at the 12-month postoperative visit. All patients were relieved of axial pain. Imaging evaluation confirmed a high fusion rate and healing rate in all patients. No patient complained of limited mobility of the cervical spine in flexion, extension and rotation. No graft or plate-related complication was observed in any patients during the whole follow-up period. The only postoperative complication was trouble in swallowing liquids in two cases which resolved three months after surgery without any treatment.

Conclusions

Anterior C3 corpectomy and fusion may prove to be safe and applicable for the treatment of complex Hangman’s fractures.