Less invasive lumbopelvic fixation technique using a percutaneous pedicle screw system for unstable pelvic ring fracture in a patient with severe multiple traumas.

Pelvic ring fractures are defined as life-threatening injuries that can be treated surgically with external or internal fixation. The authors report on an 81-year-old woman with an unstable pelvic fracture accompanying multiple traumas that was successfully treated with a less invasive procedure. The patient was injured in a traffic accident and sustained a total of 20 fractures, including pelvic ring, bilateral rib, and lumbar transverse processes fractures, and multiple fractures of both upper and lower extremities. The pelvic ring fracture was unstable with fractures of the bilateral sacrum with right sacroiliac disruption, right superior and inferior pubic rami, left superior pubic ramus, and ischium. During emergency surgery, bilateral external fixation was applied to the iliac crest to stabilize the pelvic ring. Second and third surgeries were performed 11 and 18 days after the first emergency surgery, respectively, to treat the multiple fractures. At the third surgery, the pelvic ring fracture was stabilized surgically using a less invasive posterior fixation technique. In this technique, 2 iliac screws were inserted on each side following an 8-cm midline posterior incision from the S-1 to S-3 spinous process, with the subcutaneous tissue detached from the fascia of the paraspinal muscles. The S-2 spinous process was removed and 2 rods were connected to bilateral iliac screws to stabilize the bilateral ilium in a switchback fashion. A crosslink device was applied to connect the 2 rods at the base of the S-2 spinous process. Following pelvic fixation, percutaneous pedicle screws were inserted into L-4 and L-5 vertebral bodies on both sides, and connected to the cranial rod connecting the bilateral iliac screws, thus completing the lumbopelvic fixation. The postoperative course was favorable with no postoperative complications. At the 10-month follow-up, bone union had been achieved at the superior ramus of the pubis, the patient did not complain of pain, and her activities of daily life returned to preinjury status. Unstable pelvic ring fractures need to be sufficiently stabilized for good surgical outcome. However, to avoid postoperative complications, a less invasive treatment is preferred, particularly in cases with poor general condition. This procedure is less invasive and provides sufficient stabilization to the unstable pelvic ring fracture, and thus is the ideal surgical procedure for such cases.

Inflammatory pain-related traits of sensory DRG neurons innervating the hip joints.

BACKGROUND: Hip pain is transmitted to the dorsal horn of the spinal cord via the dorsal root ganglion (DRG), which contains two types of neurons with differential sensitivity to neurotrophic factors. If either type predominantly innervates the hip joint, it may represent a good target for hip joint pain treatment. METHODS: Inflammation was induced in the left hip joint of rats (n = 10) by using complete Freund's adjuvant. Fluoro-Gold (FG) was applied to the hip joint after 7 days, and T12-L6 DRGs were double-stained for calcitonin gene-related peptide (CGRP) and isolection-IB4 1 week later. RESULTS: FG-labeled neurons in the control group were distributed throughout the left DRG from T13 to L5, primarily in L2 to L4, and CGRP-positive neurons were significantly more frequent than IB4-binding neurons. In the inflammatory group, FG-labeled neurons were similarly distributed, primarily at L3 and L4, and CGRP-positive neurons were significantly more frequent than IB4-binding neurons. The percentage of CGRP-positive neurons was significantly greater in the inflammatory group (P < 0.05). CONCLUSIONS: Most small neurons innervating the hip joint express CGRP. Furthermore, hip joint inflammation caused an increase in CGRP-positive neurons, but not in IB4-binding neurons. Our results suggest that CGRP-expressing nerve growth factor-dependent neurons are primarily responsible for hip joint pain and may represent therapeutic targets.

Influence of pelvic incidence-lumbar lordosis mismatch on surgical outcomes of short-segment transforaminal lumbar interbody fusion.

BACKGROUND: The importance of pelvic incidence-lumbar lordosis (PI-LL: PI minus LL) mismatch is emphasized in long-segment fusion for adult spinal deformity; however, there are few studies evaluating the influence of PI-LL on surgical outcomes after short-segment fusion. In this study, we have examined the effects of PI-LL mismatch on surgical outcomes of short-segment lumbar intervertebral fusion for lumbar degenerative diseases. METHODS: Patients with lumbar degenerative disease treated by short-segment (1 or 2 levels) transforaminal lumbar interbody fusion were divided into Group A (PI-LL ≤ 10°: n = 22) and Group B (PI-LL ≥ 11°: n = 30). Pre-and post-operative patient symptoms were assessed by the visual analogue scale (VAS: scores 0-100 mm; for LBP, lower-extremity pain, and lower-extremity numbness), a detailed VAS for LBP while in motion, standing, and sitting, and the Oswestry disability index (ODI). Surgical outcomes were evaluated by the Nakai score (3 = excellent to 0 = poor. Post-operative data were acquired for at least one year following surgery and were compared between the two groups. Multiple regression analyses were used to evaluate the relative influence of PI-LL on each pre-and post-operative parameter (VAS, detailed VAS and ODI) adjusted for age, sex, fusion levels, body mass index, presence of scoliosis, diabetes mellitus and depression. RESULTS: The surgical outcomes in Group A were significantly better than those of Group B. Group A showed better post-operative VAS scores for LBP, particularly LBP while standing (11.9 vs. 25.8). The results of the multivariate analyses showed no significant correlation between PI-LL and pre-operative symptoms, but did show a significant correlation between PI-LL and the post-operative VAS score for LBP, lower extremity pain, and numbness. CONCLUSIONS: This study is the first to find that PI-LL mismatch influences post-operative residual symptoms, such as LBP, lower extremity pain and numbness. Among the three types of LBP examined in the detailed VAS, LBP while standing was most strongly related to PI-LL mismatch. The importance of maintaining spinopelvic alignment is emphasized, particularly when treating patients with adult spinal deformity using long-segment fusion surgery. However, our results indicate that surgeons should pay attention to sagittal spinopelvic alignment and avoid post-operative PI-LL mismatch even when treating patients with short-segment lumbar interbody fusion.

Increase of nerve growth factor levels in the human herniated intervertebral disc: can annular rupture trigger discogenic back pain?

INTRODUCTION: Nerve growth factor (NGF) has an important role in the generation of discogenic pain. We hypothesized that annular rupture is a trigger for discogenic pain through the action of NGF. In this study, the protein levels of NGF in discs from patients with disc herniation were examined and compared with those from discs of patients with other lumbar degenerative disc diseases. METHODS: Patients (n = 55) with lumbar degenerative disc disease treated by surgery were included. Nucleus pulposus tissue (or herniated disc tissue) was surgically removed and homogenized; protein levels were quantified using an enzyme-linked immunosorbent assay (ELISA) for NGF. Levels of NGF in the discs were compared between 1) patients with herniated discs (herniated group) and those with other lumbar degenerative disc diseases (non-herniated group), and 2) low-grade and high-grade degenerated discs. Patient's symptoms were assessed using a visual analog scale (VAS) and the Oswestry disability index (ODI); the influence of NGF levels on pre- and post-operative symptoms was examined. RESULTS: Mean levels of NGF in discs of patients were significantly higher in herniated discs (83.4 pg/mg total protein) than those in non-herniated discs (68.4 pg/mg). CONCLUSIONS: This study reports that NGF increased in herniated discs, and may play an important role in the generation of discogenic pain. Analysis of patient symptoms revealed that pre-operative NGF levels were related to post-operative residual lower extremity pain and LBP in motion. The results suggest that NGF in the disc is related to pain generation, however, the impact of NGF on generation of LBP varies in individual patients.

Predictive factors for acetabular labral lesions in osteoarthritis of the hip with radial magnetic resonance imaging--a cross-sectional study.

OBJECTIVES: To document the reliability of Abe's classification and to clarify the predictive factors for acetabular labral lesions in osteoarthritis of the hip with radial magnetic resonance (MR) imaging. METHODS: Reliability trial for the classification of acetabular labral lesion was performed by six orthopedic surgeons, grading 20 radial MR images in a blinded fashion at an interval of 4-5 weeks. Radial MR images of 275 hips in 263 patients were prospectively analyzed to determine the relationship between acetabular labral lesions, their distribution, age, and the acetabular coverage. RESULTS: Cohen's quadratic weighted kappa of inter-observer reliability was 0.784 for the grade and 0.812 for the shape category. The weighted kappa of intra-observer reliability was 0.852 for the grade and 0.90 for the shape category. Multiple regression analysis revealed that both the grade and the shape were associated with age, acetabular coverage, and location of the labrum. CONCLUSIONS: Abe's classification of labral lesions was reliable for both the grade and shape categories. Aging, acetabular dysplasia, and the anterosuperior portion would be predictive factors for degeneration of the acetabular labrum using radial MR imaging.

Difficulty of diagnosing the origin of lower leg pain in patients with both lumbar spinal stenosis and hip joint osteoarthritis.

STUDY DESIGN: Case series. OBJECTIVE: To present the difficulty of diagnosing the origin of lower leg pain in patients with lumbar spinal stenosis and hip joint arthritis. SUMMARY OF BACKGROUND DATA: Pain arising from a degenerated hip joint is sometimes localized to the lower leg. Patients with lumbar spinal disease may also show radicular pain corresponding to the lower leg area. If patients present with both conditions and only pain at the lower leg, it is difficult to determine the origin of the pain. METHODS: We reviewed 420 patients who had leg pain with lumbar spinal stenosis diagnosed by myelography, computed tomography after myelography, or magnetic resonance imaging. Pain only at the ipsilateral lateral aspect of the lower leg but slight low back pain or pain around the hip joint was shown in 4 patients who had lumbar spinal stenosis and hip osteoarthritis. The symptoms resolved after L5 spinal nerve block, but remained after lidocaine infiltration into the hip joint. We performed decompression and posterolateral fusion surgery for these 4 patients. RESULTS: Leg pain did not resolve after lumbar surgery in all patients. Conservative treatment was not effective from 6 to 12 months, so ultimately we performed ipsilateral total hip replacement for all patients and they became symptom-free. CONCLUSION: It is difficult to determine the origin of lower leg pain by spinal nerve block and hip joint block in patients with lumbar spinal stenosis and hip osteoarthritis. We take this into consideration before surgery.

Acetabular liner revision using an anterolateral approach.

Total hip arthroplasty (THA) is recognized as a successful treatment for degenerative hip joint disease. An epidemiological study using the National Hospital Discharge Survey in the United States reported that the number of primary THAs increased from 119,000 in 1990 to 193,000 in 2002. According to nationwide inpatient sample data, the demand for primary THA was estimated to increase from 208,600 in 2005 to 572,000 (174%) in 2030 in the United States. The number of revision THAs in the United States has subsequently increased and is projected to increase from 40,800 in 2005 to 96,700 in 2030. Because revision THAs have a higher incidence of dislocation than primary THAs, preserving the soft tissue, including the gluteus medius muscle, is more necessary at revision THA. However, to our knowledge, few studies have reported soft tissue damage at revision THA. An anterolateral modified Watson-Jones approach, which is between the hip abductor and the tensor fascia lata, preserves the abductor muscles.This article describes 2 cases in which acetabular liner revision was performed through an anterolateral modified Watson-Jones approach. The anterolateral approach provided an excellent surgical field at acetabular liner revision, with no major complications, and has the possibility of being a useful for acetabular liner revision.

Inter-observer and intra-observer reliabilities of the Japanese Ministry of Health, Labor and Welfare type classification system for osteonecrosis of the femoral head.

The aim of this study was to clarify the reproducibility of the Japanese Ministry of Health, Labor and Welfare (JMHLW) type classification for osteonecrosis of the femoral head. We performed inter-observer and intra-observer trials using 40 sets of magnetic resonance imagings, 20 of which were produced by a 0.5 Tesla (T) superconductive unit and the other 20 produced by a 1.5 T unit, in patients with non-collapsed and asymptomatic osteonecrosis of the femoral head (JMHLW stage 1 or 2). The JMHLW type classification (A, B, C1, or C2) was determined from T1-weighted coronal images at the center of the femoral head. Six orthopedic surgeons independently assessed all 40 images twice, with an interval of 4-5 weeks between sessions. Regarding inter-observer reliability, the percent agreement was 85% and weighted kappa was 0.709 for 0.5 T, versus a percent agreement of 82% and weighted kappa of 0.724 for 1.5 T. Regarding intra-observer reliability, the percent agreement was 82% and weighted kappa was 0.780 for 0.5 T versus a percent agreement of 80% and weighted kappa of 0.800 for 1.5 T. Inter-observer and intra-observer reliabilities did not differ significantly between the 0.5 and 1.5 T units. The JMHLW type classification provided high inter-observer and intra-observer reliabilities.