Shota Ikegami

Perforation Rates of Cervical Pedicle Screw Insertion by Disease and Vertebral Level

Background: Different perforation rates for cervical pedicle screws by disease are expected in relation to bone quality and pedicle morphology; however, no report comparing pedicle screw perforation rate by disease had previously been published. This study investigated the perforation rates of pedicle screws inserted to cervical pedicle by disease and vertebral level using a CT-based navigation system. Materials/Methods: Fifty-three patients who underwent cervical pedicle screw insertion using CT based navigation system were studied. Diseases included rheumatoid arthritis (RA) (24 cases), destructive spondyloarthropathy (DSA) (10), cervical spondylotic myelopathy (CSM) (9), spine tumor (6), and cervical spondylotic myelopathy associated with athetoid cerebral palsy (CP) (4). Screw perforation rates for cervical pedicle screws were studied. Major perforation was defined as perforation 50% of screw diameter or more. Results: Major perforation rate by disease from C3 to C7 was as follows: spine tumor (0/24, 0%), RA (2/59, 3.4%), DSA (3/65, 4.6%), CP (2/20, 10.0%), and CSM (6/40, 15.0%). There were no clinically important complications such as vertebra arterial injury, spinal cord injury, or nerve root injury caused by any screw perforation. Major perforation rate by vertebral level was: C2(2/30, 6.7%), C3(4/49, 8.2%), C4(6/43, 14.0%), C5(1/32, 3.1%), C6(1/41, 2.4%), and C7(1/45, 2.2%), showing highest rate for C4, followed by C3. Conclusions: Cervical pedicle screw perforation rate by disease was higher in CSM compared to RA and DSA. The perforation rate by vertebral level was higher for C4 and C3, in this order.

What Components Comprise the Measurement of the Tibial Tuberosity-Trochlear Groove Distance in a Patellar Dislocation Population?

BACKGROUND The tibial tuberosity-trochlear groove distance is used as an indicator for medial tibial tubercle transfer; however, to our knowledge, no studies have verified whether this distance is strongly affected by tubercle lateralization at the proximal part of the tibia. We hypothesized that the tibial tuberosity-trochlear groove distance is mainly affected by tibial tubercle lateralization at the proximal part of the tibia. METHODS Forty-four patients with a history of patellar dislocation and forty-four age and sex-matched controls were analyzed with use of computed tomography. The tibial tuberosity-trochlear groove distance, tibial tubercle lateralization, trochlear groove medialization, and knee rotation were measured and were compared between the patellar dislocation group and the control group. The association between the tibial tuberosity-trochlear groove distance and three other parameters was calculated with use of the Pearson correlation coefficient and partial correlation analysis. RESULTS There were significant differences in the tibial tuberosity-trochlear groove distance (p < 0.001) and knee rotation (p < 0.001), but there was no difference in the tibial tubercle lateralization (p = 0.13) and trochlear groove medialization (p = 0.08) between the patellar dislocation group and the control group. The tibial tuberosity-trochlear groove distance had no linear correlation with tubercle lateralization (r = 0.21) or groove medialization (r = -0.15); however, knee rotation had a good positive correlation in the patellar dislocation group (r = 0.62). After adjusting for the remaining parameters, knee rotation strongly correlated with the tibial tuberosity-trochlear groove distance (r = 0.69, p < 0.001), whereas tubercle lateralization showed moderate significant correlations in the patellar dislocation group (r = 0.42; p = 0.005). CONCLUSIONS Because the tibial tuberosity-trochlear groove distance is affected more by knee rotation than by tubercle malposition, its use as an indicator for tibial tubercle transfer may not be appropriate. CLINICAL RELEVANCE Surgical decisions of tibial tubercle transfer should be made after the careful analysis of several underlying factors of patellar dislocation.

The skeletal muscle cross sectional area in long-term bisphosphonate users is smaller than that of bone mineral density-matched controls with increased serum pentosidine concentrations

Bisphosphonates are effective in increasing bone mineral density (BMD), but fragility fractures can still occur despite bisphosphonate treatment. The purpose of this study was to determine if long-term bisphosphonate users have characteristic findings in the musculoskeletal system, which could put them at risk of developing typical or atypical femoral fractures. We recruited 40 female patients who had taken bisphosphonates for more than 3 years. The control group included 60 volunteers who were matched by age, body mass index, and dual-energy X-ray absorptiometry-derived BMDs. We measured the skeletal muscle cross sectional area around the proximal thigh and buckling ratio of the femoral neck using quantitative computed tomography (qCT) and several biochemical markers of bone metabolism. Those parameters were compared between the groups. While no significant differences of buckling ratio derived from qCT were detected, the skeletal muscle cross sectional area was significantly smaller in the long-term bisphosphonate users than in the controls. Furthermore, the serum pentosidine level was significantly higher in the bisphosphonate users than in the controls. To determine if those differences were attributable to bisphosphonate treatment, we further compared those parameters between before and after 3 years of bisphosphonate treatment in 32 patients. After 3 years of bisphosphonate treatment, the BMD of the femoral neck and serum pentosidine level increased but not the skeletal muscle cross sectional area. In the present study, the skeletal muscle mass did not match the bone mass in long-term bisphosphonate users, thus suggesting that increases in BMD by bisphosphonates are unlikely to have secondary positive effects on the surrounding skeletal muscles. Also, serum pentosidine levels were greater in the long-term bisphosphonate users. Further study is necessary to test if such patients are prone to develop typical or atypical femoral fractures.

Comparison in bone turnover markers during early healing of femoral neck fracture and trochanteric fracture in elderly patients.

Healing of fractures is different for each bone and bone turnover markers may reflect the fracture healing process. The purpose of this study was to determine the characteristic changes in bone turnover markers during the fracture healing process. The subjects were consecutive patients with femoral neck or trochanteric fracture who underwent surgery and achieved bone union. There were a total of 39 patients, including 33 women and 6 men. There were 18 patients (16 women and 2 men) with femoral neck fracture and 21 patients (17 women and 4 men) with trochanteric fracture. Serum bone-specific alkaline phosphatase (BAP) was measured as a bone formation marker. Urine and serum levels of N-terminal telopeptide of type I collagen (NTX), as well as urine levels of C-terminal telopeptide of type I collagen (CTX) and deoxypyridinoline (DPD), were measured as markers of bone resorption. All bone turnover markers showed similar changes in patients with either type of fracture, but significantly higher levels of both bone formation and resorption markers were observed in trochanteric fracture patients than in neck fracture patients. BAP showed similar levels at one week after surgery and then increased. Bone resorption markers were increased after surgery in patients with either fracture. The markers reached their peak values at three weeks (BAP and urinary NTX), five weeks (serum NTX and DPD), and 2–3 weeks (CTX) after surgery. The increase in bone turnover markers after hip fracture surgery and the subsequent decrease may reflect increased bone formation and remodeling during the healing process. Both fractures had a similar bone turnover marker profile, but the extent of the changes differed between femoral neck and trochanteric fractures.

a case series of pregnancy- and lactation- associated osteoporosis and a review of the literature

The syndrome of pregnancy- and lactation-associated osteoporosis is a rare disorder whose precise etiology and treatment are largely unknown. We herein report two such cases occurring in the early postpartum period that led to multiple fragility compression fractures. Combination therapy of vitamin D and vitamin K enabled a marked gradual increase in bone mineral density.

The Pathophysiology of Primary Hip Osteoarthritis may Originate from Bone Alterations

Objectives: The aim of this study was to investigate whether bone alterations detected by hip magnetic resonance imaging (MRI) were associated with subsequent primary hip OA. Methods: We enrolled 7 patients with hip joint pain from their first visit, at which hip joints were classified as grade 0 or I on the Kellgren-Lawrence grading scale. Plain radiographs and magnetic resonance imaging (MRI) were performed on all cases, and pain was assessed with the Denis pain scale. Average age, height, weight, body mass index, bone mineral density (L1-4), central edge angle, Sharp’s angle, and acetabular hip index were calculated. Results: Within two months of the onset of pain, 4 of the 7 cases showed broad bone signal changes, while 3 cases showed local signal changes in the proximal femur on hip MRI. Three to 6 months after the onset of pain, in all patients whose pain was much improved, plain radiographs showed progression to further-stage OA. Conclusion: Our findings suggest that bone abnormalities in the proximal femur might be involved in the pathogenesis of primary hip OA.

Comparison of Clinical and Radiological Results of Posterolateral Fusion and Posterior Lumbar Interbody Fusion in the Treatment of L4 Degenerative Lumbar Spondylolisthesis

Study Design Multicenter analysis of two groups of patients surgically treated for degenerative L4 unstable spondylolisthesis. Purpose To compare the clinical and radiographic outcomes of posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) for degenerative L4 unstable spondylolisthesis. Overview of Literature Surgery for lumbar degenerative spondylolisthesis is widely performed. However, few reports have compared the outcome of PLF to that of PLIF for degenerative L4 unstable spondylolisthesis. Methods Patients with L4 unstable spondylolisthesis with Meyerding grade II or more, slip of >10° or >4 mm upon maximum flexion and extension bending, and posterior opening of >5 degree upon flexion bending were studied. Patients were treated from January 2008 to January 2010. Patients who underwent PLF (n=12) and PLIF (n=19) were followed-up for >2 years. Radiographic findings and clinical outcomes evaluated by the Japanese Orthopaedic Association (JOA) score were compared between the two groups. Radiographic evaluation included slip angle, translation, slip angle and translation during maximum flexion and extension bending, intervertebral disc height, lumbar lordotic angle, and fusion rate. Results JOA scores of the PLF group before surgery and at final follow-up were 12.3±4.8 and 24.1±3.7, respectively; those of the PLIF group were 14.7±4.8 and 24.2±7.8, respectively, with no significant difference between the two groups. Correction of slip estimated from postoperative slip angle, translation, and maintenance of intervertebral disc height in the PLIF group was significantly (p<0.05) better than those in the PLF group. However, there was no significant difference in lumbar lordotic angle, slip angle and translation angle upon maximum flexion, or extension bending. Fusion rates of the PLIF and PLF groups had no significant difference. Conclusions The L4–L5 level posterior instrumented fusion for unstable spondylolisthesis using both PLF and PLIF could ameliorate clinical symptoms when local stability is achieved.

Eldecalcitol, in Combination with Bisphosphonate, Is Effective for Treatment of Japanese Osteoporotic Patients.

Alfacalcidol (ALF) and eldecalcitol (ELD) are vitamin D analogues that can be combined with anti-resorption drugs, such as bisphosphonate (BP) for the treatment of osteoporosis (OP). There has been no report comparing the effects of those vitamin D analogs in combination with BPs. Twenty female patients with OP were enrolled, and all of them were treated with ALF and BPs. After switching from ALF to ELD, we examined the effectiveness of ALF and ELD. The averaged age was 69.4 years and the period of BP usage was between 1 to 13.4 years (mean period was 3.7 years). Serum corrected calcium, serum inorganic phosphorus, serum bone specific alkaline phosphatase (BAP), and serum tartrate-resistant acid phosphatase (TRACP)-5b were measured prior to ELD and at 6 months afterwards. Bone mineral density (BMD) of the lumbar spine (L-BMD), femoral neck, and total hip BMD were assessed one year before, prior to, and one year after ELD therapy commencement. Six months after switching from ALF to ELD, BAP and TRACP-5b values significantly decreased. After one year of ALF therapy, L-BMD, total hip BMD and femoral neck H-BMD values slightly increased. In contrast, a year following the change from ALF to ELD, L-BMD significantly increased and femoral neck BMD slightly increased, but total hip BMD did not. These results suggest that the treatment with ELD after ALF significantly suppressed bone turnover and increased L-BMD. Thus, the combined therapy with ELD is more effective for OP treatment than that with ALF.

Joint Pain Undergoes a Transition in Accordance with Signal Changes of Bones Detected by MRI in Hip Osteoarthritis

Objectives: In this study, we aimed to investigate whether joint pain is derived from cartilage or bone alterations. Methods: We reviewed 23 hip joints of 21 patients with primary hip osteoarthritis (OA), which were classified into Kellgren–Laurence (KL) grading I to IV. Plain radiographs and magnetic resonance imaging (MRI) were obtained from all of the 23 joints. Two of the 21 patients had bilateral hip OA. Pain was assessed based on the pain scale of Denis. A Welch t test was performed for age, height, weight, body mass index, bone mineral density, and a Mann–Whitney U test was performed for KL grading. Results: Four of 8 hip joints with pain and OA showed broad signal changes detected by MRI. Fourteen hip joints without pain, but with OA did not show broad signal changes by MRI. Collectively, MRI analyses showed that broad signal changes in OA cases without joint pain or with a slight degree of joint pain were not observed, while broad signal changes were observed in OA cases with deteriorated joint pain. Conclusion: Our findings suggest that hip joint pain might be associated with bone signal alterations in the hips of OA patients.

Associations of self-reported height loss and kyphosis with vertebral fractures in Japanese women 60 years and older: a cross-sectional survey

Some vertebral fractures come to clinical attention but most do not. This cross-sectional survey aimed to clarify the associations of self-reported height loss and kyphosis with vertebral fractures. We enrolled 407 women aged 60–92 years who visited our orthopaedic clinic between June and August 2014 in our study. Inclusion criteria were lateral radiography followed by completion of a structured questionnaire in this study. The primary outcome was vertebral fracture diagnosed on lateral radiography and graded using a semiquantitative grading method, from SQ0 (normal) to SQ3 (severe). Self-reported kyphosis was defined as none, mild to moderate, severe. Self-reported height loss was defined as <4 cm or ≥4 cm. Number of SQ1 fracture was associated only with kyphosis. Self-reported severe kyphosis was significantly associated with increased numbers of ≥SQ2 vertebral fractures (p = 0.007). Height loss ≥4 cm was significantly associated with increased ≥SQ2 grade fractures (p < 0.001). Odds ratios (ORs) for fractures associated with mild-to-moderate and severe kyphosis were 2.1 [95% confidence interval 1.4 to 3.3) and 4.2 (1.8 to 9.5), respectively. OR for fractures associated with height loss ≥4 cm was 2.3 (1.4 to 3.7). Self-reported kyphosis may be useful for identifying Japanese women aged ≥60 years who have undetected vertebral fractures.