Frequency-response relationship between exercise and locomotive syndrome across age groups: Secondary analysis of a nationwide cross-sectional study in Japan.

OBJECTIVES: This study aimed to clarify the frequency-response relationship between exercise habits and locomotive syndrome (LS) in different age groups. METHODS: We analysed 8681 independent community dwellers who participated in a nationwide cross-sectional LS study. Participants were divided into young (20-39 years), middle (40-64 years), and old (≥ 65 years) groups. The presence of LS was evaluated using the LS risk tests. Exercise habits were assessed by exercise frequency (almost every day/sometimes/occasionally/never). The association between LS and exercise was assessed using the multiple logistic regression analysis adjusted for participant characteristics for each age category. RESULTS: Overall, 3528 (41%) participants had LS. In the old group, the risk of LS was lower with an increased exercise frequency. However, this dose-response relationship was not found in the young group. The proportion of LS was lower even in participants who occasionally exercised (1-3 days/month) than those who never exercise in the young and middle age groups. CONCLUSIONS: Regular exercise reduced the risk of LS not only in middle and older adults but also in young adults. Moreover, increasing exercise frequency may provide benefits for LS prevention, especially among older adults.

Reference values for the locomotive syndrome risk test quantifying mobility of 8681 adults aged 20-89 years: A cross-sectional nationwide study in Japan.

BACKGROUND: The locomotive syndrome risk test was developed to quantify the decrease in mobility among adults, which could eventually lead to disability. The purpose of this study was to establish reference values for the locomotive syndrome risk test for adults and investigate the influence of age and sex. METHODS: We analyzed 8681 independent community dwellers (3607 men, 5074 women). Data pertaining to locomotive syndrome risk test (the two-step test, the stand-up test, and the 25-question geriatric locomotive function scale [GLFS-25]) scores were collected from seven administrative areas of Japan. RESULTS: The reference values of the three test scores were generated and all three test scores gradually decreased among young-to-middle-aged individuals and rapidly decreased in individuals aged over 60 years. The stand-up test score began decreasing significantly from the age of 30 years. The trajectories of decrease in the two-step test score with age was slightly different between men and women especially among the middle-aged individuals. The two physical test scores were more sensitive to aging than the self-reported test score. CONCLUSION: The reference values generated in this study could be employed to determine whether an individual has mobility comparable to independent community dwellers of the same age and sex.

Introduction of integrated dental training jaw models and rubric criteria.

OBJECTIVE: The objective of the present study was to evaluate the effectiveness of introducing integrated jaw models, rubric criteria and homework tasks to a total clinical simulation training course to improve the clinical competence of preclinical dental students. METHODS: A total simulation training course, which involved six clinical dentistry departments, was held for 110 preclinical students in 2014 and 2015. We prepared integrated jaw models having several morbidities along with corresponding medical information and homework tasks. The students formulated diagnoses and devised treatment plans before performing dental treatment on the mannequin under the direction of instructors from the respective clinical departments. Their performance was assessed by both students and instructors using the rubric criteria. RESULTS: Based on quantitative evaluations, the introduction of integrated jaw models appeared to improve the students' ability to formulate diagnoses and devise dental treatment plans and to understand the respective clinical dentistry disciplines. The rubric criteria provided immediate feedback for the students. Based on a comparison of rubric scores, students tended to significantly underestimate their own performance compared with instructors. Moreover, the introduction of homework tasks improved student seriousness. CONCLUSION: Introducing integrated jaw models, rubric criteria and homework tasks to a total simulation training course may be a good approach for improving student performance in terms of dental diagnoses and treatment.

Chronological Changes in Axial Alignment of the Ipsilateral Hip and Knee After Total Hip Arthroplasty.

BACKGROUND: Internal rotation of the hip and lateral patellar tilt increases after total hip arthroplasty (THA). However, it remains unknown whether these parameters change with time after the index THA. METHODS: A total of 91 patients undergoing 2-stage bilateral primary THAs between January 2008 and May 2014 were included to assess the association of chronological changes in internal rotation of the hip or lateral patellar tilt with anthropometric and perioperative parameter and changes in alignment after the index THA. Chronological changes were assessed as changes between postoperative computed tomography on the index surgery and the preoperative computed tomography on the contralateral THA. Internal rotation of the hip was defined as the angle between the posterior intercondylar line and a line passing through the posterior inferior iliac spines. Lateral patellar tilt was defined as the angle between the posterior intercondylar line and a line joining the medial and lateral edges of the patella. RESULTS: Internal rotation of the hip and lateral patellar tilt changed until 2 years after the index surgery by a mean of -2° (range -17.3° to 17.7°) and -2° (range -18.2° to 5.3°), respectively. Adductor tenotomy was associated with increasing internal rotation of the hip with time (adjusted R2 0.076); leg lengthening and larger preoperative femorotibial angle were associated with decreasing lateral patellar tilt with time (adjusted R2 0.159). CONCLUSION: Both internal rotation of the hip at rest and lateral patellar tilt decreased by approximately 2° until 2 years after surgery and there was a large variation in chronological change.

Clinical benefit of graduated compression stockings for prevention of venous thromboembolism after total knee arthroplasty: post hoc analysis of a phase 3 clinical study of edoxaban.

BACKGROUND: Guidelines from the Japanese Circulation Society recommend prophylaxis with anticoagulation plus intermittent pneumatic compression or graduated compression stockings (GCS) among patients at the highest risk for developing venous thromboembolism (VTE). However, the benefits of concomitant GCS use for patients undergoing total knee arthroplasty (TKA) and receiving anticoagulation remain unknown. In this study, the efficacy of GCS plus anticoagulation compared with anticoagulation alone was evaluated among patients undergoing TKA. METHODS: This study is a post hoc analysis of a previously reported phase 3 trial involving patients undergoing TKA. In the primary study, which permitted the use of GCS for mechanical prophylaxis, patients were randomized to receive edoxaban 30 mg once daily or enoxaparin 20 mg twice daily for 11 to 14 days following TKA. The primary endpoint was the incidence of VTE, a composite of symptomatic deep vein thrombosis (DVT), symptomatic pulmonary embolism (PE), and asymptomatic DVT. Treatment comparisons were performed using the chi-square test, and the 95 % confidence intervals were calculated. RESULTS: Among patients receiving edoxaban, the incidence of VTE was 3.8 and 5.8 % for patients with and without GCS, respectively. For patients receiving enoxaparin, VTE incidence was 8.4 and 20.8 % among those with and without GCS, respectively. Overall, VTE incidence was 6.0 and 13.0 % for anticoagulated patients with and without GCS mechanical prophylaxis, respectively. No deaths or symptomatic PE were reported during this study. CONCLUSIONS: Although the incidence of VTE was >2-fold lower among patients receiving anticoagulation plus GCS compared with those receiving anticoagulation alone, statistical significance was not achieved. Further studies are required to confirm the findings of this preliminary analysis. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01181102.

Edoxaban versus enoxaparin for the prevention of venous thromboembolism after total knee or hip arthroplasty: pooled analysis of coagulation biomarkers and primary efficacy and safety endpoints from two phase 3 trials.

BACKGROUND: The objective of this analysis was to assess the effects of edoxaban compared with enoxaparin on key coagulation biomarkers and present pooled primary efficacy and safety results from phase 3 STARS E-3 and STARS J-V trials for prevention of venous thromboembolism (VTE) after total knee arthroplasty (TKA) or total hip arthroplasty (THA). METHODS: In the randomized, double-blind, double-dummy, multicenter, STARS E-3 and STARS J-V trials, patients received edoxaban 30 mg or enoxaparin 2000 IU (20 mg) twice daily for 11 to 14 days. The studies were conducted in Japan and Taiwan; enoxaparin dosing was based on Japanese label recommendations. The primary efficacy endpoint was incidence of VTE; the safety endpoint was major or clinically relevant nonmajor (CRNM) bleeding. Blood samples were taken at presurgical evaluation, pretreatment (postsurgery), predose on day 7, predose on completion of treatment, and at a follow-up examination 25 to 35 days after the last dose of study drug for D-dimer, prothrombin fragment 1 + 2 (F1+2), and soluble fibrin monomer complex (SFMC) measurement. RESULTS: A total of 716 patients enrolled in STARS E-3 and 610 patients enrolled in STARS J-V; 1326 patients overall. This analysis included 657 patients who received edoxaban 30 mg QD and 650 patients who received enoxaparin 20 mg BID. Incidence of VTE was 5.1 and 10.7% for edoxaban and enoxaparin, respectively (P <0.001). Incidence of combined major and CRNM bleeding was 4.6 and 3.7% for edoxaban and enoxaparin, respectively (P = 0.427). On day 7, mean D-dimer (4.4 vs 5.5 µg/mL), F1+2 (363 vs 463 pmol/L), and SFMC (5.7 vs 6.8 µg/mL) were lower in edoxaban-treated patients relative to enoxaparin-treated patients, respectively (P <0.0001 for all). At end of treatment, mean D-dimer (5.4 vs 6.2 µg/mL), F1+2 (292 vs 380 pmol/L), and SFMC (6.2 vs 7.2 µg/mL) were lower in edoxaban-treated patients relative to enoxaparin-treated patients (P <0.0001 for all). CONCLUSIONS: Edoxaban was superior to enoxaparin in prevention of VTE following TKA and THA, with comparable rates of bleeding events. Relative to enoxaparin, edoxaban significantly reduced D-dimer, F1+2, and SFMC. TRIAL REGISTRATION: Clintrials.gov NCT01181102 and NCT01181167. Both registered 8/12/2010.

Efficacy and safety of edoxaban versus enoxaparin for the prevention of venous thromboembolism following total hip arthroplasty: STARS J-V.

BACKGROUND: In the absence of thromboprophylaxis, patients undergoing total hip arthroplasty (THA) are at increased risk for venous thromboembolism (VTE). The objective of this study was to compare the efficacy and safety of edoxaban with enoxaparin for the prevention of VTE after THA in Japan. METHODS: This was a phase 3, double-blind, double-dummy, noninferiority study. Patients undergoing elective, unilateral primary THA were randomized to receive edoxaban 30 mg once daily (n = 307) or enoxaparin 2000 IU (equivalent to 20 mg) twice daily (n = 303) for 11 to 14 days. The primary efficacy endpoint was the incidence of VTE. Safety endpoints included the incidence of major or clinically relevant nonmajor (CRNM) bleeding. RESULTS: The incidence of VTE, based on venography and clinical surveillance, was 2.4 % in the edoxaban group and 6.9 % in the enoxaparin group (P <0.001). The absolute difference in the incidence of VTE was -4.5 % (95 % confidence interval [CI]: -8.6, -0.9), which was within the noninferiority margin set at 8 % for the difference and established the noninferiority of edoxaban to enoxaparin. Since the upper limit of the 95 % CI of the absolute difference was less than 0 %, the superiority of edoxaban over enoxaparin was demonstrated. The incidence of major or CRNM bleeding was 2.6 % in the edoxaban group and 3.7 % in the enoxaparin group (P = 0.475). CONCLUSIONS: Oral edoxaban 30 mg once daily was superior to subcutaneous enoxaparin 2000 IU twice daily in the prevention of VTE following THA without increasing the risk for major or CRNM bleeding.

A randomized, open-label trial of edoxaban in Japanese patients with severe renal impairment undergoing lower-limb orthopedic surgery.

BACKGROUND: Edoxaban is an oral, direct, factor Xa inhibitor approved in Japan for thromboembolic prophylaxis after lower-limb orthopedic surgery (LLOS), but contraindicated in patients with severe renal impairment (SRI; creatinine clearance [CLCR] ≥15 to <30 mL/min). METHODS: This open-label study compared the safety of edoxaban 15 mg once daily in Japanese patients with SRI to that of edoxaban 30 mg in patients with mild renal impairment (MiRI; CLCR ≥50 to ≤80 mL/min; N = 30) undergoing LLOS. Patients with CLCR ≥20 to <30 mL/min were randomized to receive edoxaban 15 mg (N = 22) or subcutaneous fondaparinux 1.5 mg once daily (N = 21). All patients with CLCR ≥15 to <20 mL/min received edoxaban 15 mg (N = 7). Treatment was administered for 11 to 14 days. RESULTS: Major or clinically relevant non-major bleeding occurred in 6.7%, 3.4%, and 5.0% of patients in the MiRI edoxaban 30-mg, SRI edoxaban 15-mg, and SRI fondaparinux groups, respectively; there were no major bleeding events. No thromboembolic events occurred. At all time points assessed, edoxaban plasma concentrations and changes in coagulation biomarkers were similar between the SRI and MiRI groups. CONCLUSIONS: These results suggest edoxaban 15 mg once daily is well tolerated in Japanese patients with SRI undergoing LLOS. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT01857583.

Preoperative morphometric differences in the distal femur are based on skeletal size in Japanese patients undergoing total knee arthroplasty.

PURPOSE: The objectives of this study were to measure the morphometric parameters of preoperative distal femurs to determine the differences by diagnosis and gender after accounting for skeletal size. METHODS: One-hundred and seventy-nine Japanese patients who underwent total knee arthroplasty (TKA) (25 males and 154 females) were assessed. The anteroposterior length (AP), mediolateral width (ML), aspect ratio (AR), surgical epicondylar axis (SEA) to posterior condylar axis (PCA) angle, and Whiteside to SEA angle were measured on preoperative computed tomography scans. The AP/ML, AR/ML, SEA/PCA, and Whiteside/PCA relationships were evaluated and compared by patient diagnosis and gender. The results were also compared with the sizes of 10 currently available TKA implants in Japan. RESULTS: The mean AP, ML, AR, SEA/PCA angle, and Whiteside/PCA angle were 58.8 mm, 64.7 mm, 0.91, external rotation (ER) 3.5°, and ER 1.6°, respectively. AP and AR each were significantly correlated with ML (p < 0.001). AP, ML, and AR were not significantly different between patients diagnosed with osteoarthritis and rheumatoid arthritis. AP/ML and AR/ML were significantly correlated within each diagnosis (p < 0.001), but the analysis of covariance showed no significant differences between the diagnoses. AP and ML were significantly longer (p < 0.001) in males (63.6, 72.7 mm) than in females (58.1, 63.4 mm), while AR was smaller in males (0.88 vs. 0.92), with significant correlations for AP/ML (male: p < 0.010, female: p < 0.001) and AR/ML (male: p = 0.002, female: p < 0.001) in each gender. However, the analysis of covariance showed no significant differences between gender in the AP/ML and AR/MR correlations. The AP/ML ratio of our data was similar to the size variations of the 10 TKA implants, but the AR/ML ratio was quite different from almost all the implants. CONCLUSIONS: No differences in preoperative femur morphometry were found between patients with different diagnoses, but the gender difference in AR was related to the difference in skeletal size between males and females. LEVEL OF EVIDENCE: Case series with no comparison groups, Level IV.

Repair of Achilles tendon rupture using autologous semitendinosus graft in a kidney transplant recipient.

Insertional Achilles tendon injuries can be difficult to treat when minimal tendon tissue remains for anastomosis. Moreover, in the chronic case with tendon shortening, operative repair can be more difficult than acute rupture. It is particularly desirable to reinforce the tendons, in addition to performing primary repair, in patients with renal or systemic diseases because of the accelerated collagen degeneration. Many techniques have been described for the surgical management of Achilles tendon rupture; however, none has shown clear superiority. We report the case of a 50-year-old renal transplant patient with a spontaneous distal Achilles tendon injury that we repaired using the pull-out technique reinforced with an autologous semitendinosus graft. At 2 years postoperatively, the ankle-hindfoot scale score was 92 points, and the postoperative course was without complication. We believe that the free hamstring tendon autograft is advantageous for this repair, because it is easy to handle, has limited donor site morbidity, and preserves the structures around the ankle.

Finger-tapping motion analysis in cervical myelopathy by magnetic-sensor tapping device.

STUDY DESIGN: Case-control study. OBJECTIVES: The purpose of this study is to determine finger motion of patients with cervical myelopathy during finger-tapping cycles. SUMMARY OF BACKGROUND DATA: A major symptom of patients with compressive cervical myelopathy is finger clumsiness. Therefore, understanding finger motion is prerequisite in assessing the severity of myelopathy. The popular grip-and-release test evaluates only the number of motion cycles, which is insufficient to fully describe complex finger motion. METHODS: Forty-three patients with cervical myelopathy and 41 healthy controls tapped their index fingers against their thumbs as rapidly as possible for 30 seconds and the motion was recorded by a magnetic-sensor coil attached to the nail surface. Output signals were stored in a computer, which automatically calculated tapping frequency, distance moved, ratio of opening/closing velocity and the SD of the tapping interval. RESULTS: The SD of the tapping interval was significantly greater and all other measures were significantly smaller in patients with cervical myelopathy, than in healthy controls. All indices significantly improved after surgical decompression of the cervical spine. Distance moved (Pearson correlation coefficient: r=0.590, P<0.001) and the SD of the tapping interval (r=-0.451; P=0.002) were significantly correlated with the Japanese Orthopedic Association score (neurological scale). CONCLUSION: The quantitative evaluation of finger paralysis was performed by this tapping device. Speed and regularity in repetitive motion of fingers were correlated with the severity of cervical myelopathy.

Progressive spinal destruction secondary to minimal vertebral fracture in a patient with diffuse idiopathic skeletal hyperostosis: a case report.

Early operative fixation is widely recognized as essential for managing spinal fractures in patients with diffuse idiopathic skeletal hyperostosis (DISH). However, no report to date has addressed the occurrence of minimal vertebral fractures diagnosable only through magnetic resonance imaging (MRI) in these patients and the associated temporal changes in the fracture site. In this report, we describe a rare clinical case involving an 81-year-old man who developed progressive spinal destruction secondary to a minimal vertebral fracture. MRI showed minimum-intensity changes in the T12 vertebral body, whereas X-ray and computed tomography examinations showed DISH and no spinal fracture. Despite experiencing severe low back pain, the patient did not undergo operative therapy for 2 months, resulting in progressive spinal destruction. Spinal fusion with posterior instrumentation was performed, and the patient was followed for 1 year with no symptoms and good functional status. This case emphasizes the importance of clinicians being cautious to avoid overlooking and undervaluing minimal vertebral fractures diagnosable only through MRI in patients with DISH.

Disc space distraction is a potent risk factor for adjacent disc disease after PLIF.

UNLABELLED: We reported that excessive disc space distraction caused by insertion of large cages during posterior lumbar interbody fusion (PLIF) combined with pedicle screws (PS) induces adjacent segment disease (ASD). Spinous process plate (SPP) is known to allow cage subsidence when used in PLIF, since they cannot share vertical loads. We therefore hypothesize that the incidence of ASD after PLIF with SPP should be lower than that after PLIF with PS due to this loss of disc space distraction. MATERIALS AND METHODS: Radiographic ASD is defined as development of spondylolisthesis > 3 mm, decrease in disc height > 3 mm, or intervertebral angle at flexion lesser than -5°. Symptomatic ASD is defined by a decrease of ≥ 4 points in Japanese Orthopedic Association score. One hundred and thirty patients with L4 spondylolisthesis were treated with either PLIF with SPP (n = 45) or PLIF with PS (n = 85) and followed up for a minimum of 2 years (mean, 39.0 months). RESULTS: L4-5 disc space distraction in the SPP group was significantly smaller (0.4 mm) as compared to the PS group (1.8 mm). The incidence of clinical ASD in the SPP group (2%, 1/45) was also significantly less than that in the PS group (15%, 13/85). Multivariate analysis showed that disc space distraction was the most significant risk factor. CONCLUSIONS: Among various risk factors for ASD after PLIF, the excessive distraction of disc space proved to be a potent risk factor for ASD.

Late infection of total knee arthroplasty inflamed by anti-TNFalpha, Infliximab therapy in rheumatoid arthritis.

We report a case of sudden onset of late infection after TKA inflamed by anti-TNFalpha therapy, Infliximab, in a 54-year-old woman with RA. Infliximab therapy was started 3 years and 8 months after TKAs as a result of multiple arthritides showing high inflammation of RA. One week after the third administration of Infliximab, the patient suffered sudden knee pain and infectious clinical symptoms, and bacteria (MSSA) were detected by joint effusion culture. She was successfully treated by open debridement with antibiotics-loaded calcium phosphate bone paste and cement and the prostheses were retained. Early diagnosis and operative treatment might be the key to controlling infected TKA without removing the implant. This present case might indicate a serious risk of immunosuppressive effects caused by Infliximab.

Dabigatran etexilate prevents venous thromboembolism after total knee arthroplasty in Japanese patients with a safety profile comparable to placebo.

We assessed the efficacy, safety, and dose-response of dabigatran etexilate (DAB) in preventing venous thromboembolism (VTE) in Japanese patients undergoing total knee arthroplasty (TKA). Five hundred twelve patients received DAB (110, 150, or 220 mg) or placebo once daily for 11 to 14 days, starting the day after surgery. The primary efficacy end point was the incidence of total VTE and all-cause mortality; the primary safety end point was incidence of major, clinically relevant, and minor bleeding events. Total VTE and all-cause mortality were lower in patients receiving DAB (39.6%, 32.7%, and 24.0%) than placebo (56.4%). There was no difference in the incidence of major bleeding between the DAB and placebo groups. Overall, DAB reduced the incidence of VTE in Japanese patients undergoing TKA, with a comparable safety profile vs placebo.

Two-level Posterior Lumbar Interbody Fusion at the Lumbosacral Segment has a High Risk of Pseudarthrosis and Poor Clinical Outcomes: Comparison Between the Lumbar and Lumbosacral Segments.

STUDY DESIGN: This was a retrospective study. OBJECTIVES: The purposes of this study were to investigate the fusion rate and clinical outcomes of 2-level posterior lumbar interbody fusion (PLIF). SUMMARY OF BACKGROUND DATA: PLIF provides favorable clinical outcomes and a high fusion rate. However, most extant studies have been limited to the results of single-level PLIF. Clinical outcomes and fusion rate of 2-level PLIF are unknown. MATERIALS AND METHODS: In total, 73 patients who underwent 2-level PLIF below L3 between 2008 and 2016 (follow-up period >2 y) were included. Patients were divided into the 2 groups on the basis of surgical level. The lumbar group included 48 patients who underwent L3/4/5 PLIF, and the lumbosacral group included 25 patients who underwent L4/5/S PLIF. Fusion rate and clinical outcomes were compared. The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and a visual analog scale were used for evaluation. RESULTS: Fusion rate was significantly lower in the lumbosacral group (lumbar 96% vs. lumbosacral 64%; P<0.001). Eight of 9 cases of pseudarthrosis occurred at the lumbosacral segment. Improvement in the mental health domain of the JOAPEQ was significantly lower in the lumbosacral group (lumbar 16 vs. lumbosacral 10; P=0.02). The VAS data showed that improvements in the following variables were significantly lower in the lumbosacral group than in the lumbar group: pain in low back (lumbar -38 vs. lumbosacral -23; P=0.004), pain in buttocks or lower leg (lumbar -48 vs. lumbosacral -29; P=0.04), and numbness in buttocks or lower leg (lumbar -44 vs. lumbosacral -33; P=0.04). CONCLUSIONS: Two-level PLIF at the lumbosacral segment demonstrated a significantly lower fusion rate and poorer clinical outcomes than that at the lumbar-only segments. Some reinforcement for the sacral anchor is recommended to improve fusion rate, even for short fusion like 2-level PLIF, if the lumbosacral segment is included. LEVEL OF EVIDENCE: Level III.

Postoperative displacement of hydroxyapatite spacers implanted during double-door laminoplasty.

OBJECT: Double-door laminoplasty using hydroxyapatite (HA) spacers has been widely performed for compressive cervical myelopathy and has provided good neurological outcome. Although HA spacers are used for preventing reclosure of the opened laminae, they are often displaced or dislocated from their original position. The authors investigated the incidence and patterns of postoperative HA spacer displacement to determine the reasons for this unfavorable event. METHODS: Eighty-six patients with compressive myelopathy underwent double-door laminoplasty in which a total of 278 HA spacers were used. The displacement of HA spacers and opened laminae were assessed using postoperative lateral radiographs and CT scans. RESULTS: Postoperative dorsal migration > 2 mm was found in 116 (42%) of 278 implanted HA spacers. In addition, 33 (38%) of 86 HA spacers rotated > 10 degrees and 29 (34%) of the 86 opened laminae tilted > 10 degrees. Moreover, deformation of the newly formed spinal canal was observed in 51 (59%) of 86 cases, and bone fusion between the HA spacer and spinous process was achieved in only 15 (8.7%) of 172 cases. Neurological worsening and neck pain, however, were not associated with displacement of HA spacers or deformation of the spinal canal. CONCLUSIONS: In double-door laminoplasty, postoperative displacement of the HA spacer with deformation of the enlarged spinal canal occurred frequently. Hydroxyapatite spacers tend to become displaced after surgery. Placing the HA spacer at the base of the spinous process close to the dura mater may prevent postoperative displacement.

Bone stock reconstruction for huge bone loss using allograft-bones, bone marrow, and teriparatide in an infected total knee arthroplasty.

Bone stock reconstruction using allograft-bones, bone marrow (BM), and teriparatide (TPTD) is reported. Huge and extensive bone losses occurred in the medullary cavity of the femur and tibia of a 55-year-old female rheumatoid arthritis patient with severe osteoporosis after debridement of her infected total knee arthroplasty. Because of the risks of unstable prosthetic fixation and intra-operation fracture, we first reconstructed the bone stock. Chipped allograft bones mixed with BM were implanted in the bone defects, and TPTD was administrated for the osteoporosis therapy. Good bone formation was found by computed tomography after 4 months. Bone turnover markers and bone mineral density (BMD) were increased at 6 months. We confirmed good bone formation at the re-implantation surgery. The newly formed bone harvested during the re-implantation surgery showed active osteoblast-like lining cells. TPTD is known to enhance allograft bone union, mesenchymal stem cell differentiation into osteoblasts, and BMD. This tissue engineering-based technique might be improved by the various effects of TPTD. This method without any laboratory cell culture might be a good option for bone stock reconstruction surgery in ordinary hospitals.

Early cephalad adjacent segment degeneration after posterior lumbar interbody fusion: a comparative study between cortical bone trajectory screw fixation and traditional trajectory screw fixation.

OBJECTIVE: Cortical bone trajectory (CBT) screw insertion through a caudomedial starting point provides advantages in limiting dissection of the superior facet joints and reducing muscle dissection and the risk of superior-segment facet violation by the screw. These advantages of the cephalad CBT screw can result in lower rates of early cephalad adjacent segment degeneration (ASD) after posterior lumbar interbody fusion (PLIF) with CBT screw fixation (CBT-PLIF) than those after PLIF using traditional trajectory screw fixation (TT-PLIF). Here, the authors investigated early cephalad ASD after CBT-PLIF and compared these results with those after TT-PLIF. METHODS: The medical records of all patients who had undergone single-level CBT-PLIF or single-level TT-PLIF for degenerative lumbar spondylolisthesis (DLS) and with at least 3 years of postsurgical follow-up were retrospectively reviewed. At 3 years postoperatively, early cephalad radiological ASD changes (R-ASD) such as narrowing of disc height (> 3 mm), anterior or posterior slippage (> 3 mm), and posterior opening (> 5°) were examined using lateral radiographs of the lumbar spine. Early cephalad symptomatic adjacent segment disease (S-ASD) was diagnosed when clinical symptoms such as leg pain deteriorated during postoperative follow-up and the responsible lesion suprajacent to the fused segment was confirmed on MRI. RESULTS: One hundred two patients underwent single-level CBT-PLIF for DLS and were followed up for at least 3 years (CBT group). As a control group, age- and sex-matched patients (77) underwent single-level TT-PLIF for DLS and were followed up for at least 3 years (TT group). The total incidence of early cephalad R-ASD was 12.7% in the CBT group and 41.6% in the TT group (p < 0.0001). The incidence of narrowing of disc height, anterior slippage, and posterior slippage was significantly lower in the CBT group (5.9%, 2.0%, and 4.9%) than in the TT group (16.9%, 13.0%, and 14.3%; p < 0.05). Early cephalad S-ASD developed in 1 patient (1.0%) in the CBT group and 3 patients (3.9%) in the TT group; although the incidence was lower in the CBT group than in the TT group, no significant difference was found between the two groups. CONCLUSIONS: CBT-PLIF, as compared with TT-PLIF, significantly reduced the incidence of early cephalad R-ASD. One of the main reasons may be that cephalad CBT screws reduced the risk of proximal facet violation by the screw, which reportedly can increase biomechanical stress and lead to destabilization at the suprajacent segment to the fused segment.