Changes in axial alignment of the ipsilateral hip and knee after total hip arthroplasty

AIMS

We investigated changes in the axial alignment of the ipsilateral hip and knee after total hip arthroplasty (THA).

PATIENTS AND METHODS

We reviewed 152 patients undergoing primary THA (163 hips; 22 hips in men, 141 hips in women) without a pre-operative flexion contracture. The mean age was 64 years (30 to 88). The diagnosis was osteoarthritis (OA) in 151 hips (primary in 18 hips, and secondary to dysplasia in 133) and non-OA in 12 hips. A posterolateral approach with repair of the external rotators was used in 134 hips and an anterior approach in 29 hips. We measured changes in leg length and offset on radiographs, and femoral anteversion, internal rotation of the hip and lateral patellar tilt on CT scans, pre- and post-operatively.

RESULTS

The mean internal rotation increased by 11° (-15° to 46°) and was associated with underlying disease (OA), pre-operative range of internal rotation, gender, surgical approach, leg lengthening, and change of femoral anteversion (adjusted R(2) : 0.253, p < 0.001). The mean lateral patellar tilt increased by 4° (-5° to 14°) and was associated with age, leg lengthening, and increment of hip internal rotation (adjusted R(2): 0.193, p < 0.001).

CONCLUSION

Both internal rotation of the hip at rest and lateral patellar tilt are increased after THA. Changes in rotation after THA may affect gait, daily activities, the rate of dislocation of the hip, and ipsilateral knee pain.

TAKE HOME MESSAGE

Internal rotation of the hip at rest and lateral patellar tilt increase after THA.

Significant reduction in the incidence of C5 palsy after cervical laminoplasty using chilled irrigation water

Aims

The aim of this study was to determine whether chilled irrigation saline decreases the incidence of clinical upper limb palsy (ULP; a reduction of one grade or more on manual muscle testing; MMT), based on the idea that ULP results from thermal damage to the nerve roots by heat generated by friction during bone drilling.

Methods

Irrigation saline for drilling was used at room temperature (RT, 25.6°C) in open-door laminoplasty in 400 patients (RT group) and chilled to a mean temperature of 12.1°C during operations for 400 patients (low-temperature (LT) group). We assessed deltoid, biceps, and triceps brachii muscle strength by MMT. ULP occurring within two days post-operatively was categorised as early-onset palsy.

Results

The incidence of ULP (4.0% vs 9.5%, p = 0.003), especially early-onset palsy (1.0% vs 5.5%, p < 0.001), was significantly lower for the LT group than for the RT group. Multivariate analysis indicated that RT irrigation saline use, concomitant foraminotomy, and opened side were significant predictors for ULP.

Discussion

Using chilled irrigation saline during bone drilling significantly decreased the ULP incidence, particularly the early-onset type, and shortened the recovery period for ULP. Chilled irrigation saline can thus be recommended as a simple method for preventing ULP. Take home message: Chilled irrigation during laminoplasty reduces C5 palsy. Cite this article: Bone Joint J 2016;98-B:117–24.

Eight-year preservation of knee function with radiographic healing phenomena after anti-tumor necrosis factor-α therapy for a severely erosive knee in a young patient with rheumatoid arthritis

A 23-year-old woman developed rheumatoid arthritis (RA). The pain in her right knee was aggravated and anti-tumor necrosis factor (TNF)-α therapy was selected at the age of 35. The range of motion and Larsen grade were 5º to 120º and 4, respectively. Infliximab and etanercept therapies were quite effective and the pain of the right knee improved. An X-ray at 1 year showed radiographic healing phenomena that included reappearance of a clear visible cortical plane, partial filling-in of erosions and cysts, and sclerosis of the subchondral bone. An X-ray at the age of 43 showed that the radiographic healing phenomena were still preserved after 7 years. The right knee remained pain-free although the Larsen grade was still 4, and the knee function was preserved for 8 years. In conclusion, anti-TNF-α therapy may preserve knee function with radiographic healing phenomena and prevent total arthroplasty of severely erosive knees in young RA patients.

Safety and efficacy of edoxaban, an oral factor xa inhibitor, for thromboprophylaxis after total hip arthroplasty in Japan and Taiwan

Edoxaban, an oral direct factor Xa inhibitor, has proven antithrombotic efficacy. In a multicenter, phase II study, 264 total hip arthroplasty (THA) patients randomly received edoxaban 15 or 30 mg once daily or enoxaparin 2000IU (20-mg) twice daily for 11-14 days. Thromboembolic event incidences were 3.8% (3/78), 2.8% (2/72), and 4.1% (3/74) for edoxaban 15-mg, 30-mg, and enoxaparin, respectively (P=1.00). Edoxaban-induced prolongation of prothrombin time, international normalized ratio, and activated partial thromboplastin time were proportional to plasma edoxaban concentration. Major or clinically relevant non-major bleeding incidences were 2.2% (2/89), 1.2% (1/85), and 2.3% (2/87) for edoxaban 15-mg, 30-mg, and enoxaparin, respectively (P=1.00). Once-daily edoxaban showed similar efficacy and safety to enoxaparin for prevention of thromboembolic events in patients undergoing THA.

Single-shot detection of mid-infrared spectra by chirped-pulse upconversion with four-wave difference frequency generation in gases

Single-shot detection of ultrabroadband mid-infrared spectra was demonstrated by using chirped-pulse upconversion technique with four-wave difference frequency generation in gases. Thanks to the low dispersion of the gas media, the bandwidth of the phase matching condition of the upconversion process becomes very broad and the entire mid-infrared spectrum spanning from 200 to 5500 cm(-1) was upconverted by using a 10 ps chirped pulse to visible wavelength radiation, which was detected with a conventional visible dispersive spectrometer. This method was demonstrated by the successful measurement of infrared absorption spectra of organic polymer films.

Migration ecology of juvenile temperate seabass Lateolabrax japonicus: a carbon stable-isotope approach

The migration pattern of juvenile temperate seabass Lateolabrax japonicus in the stratified estuary of the Yura River was examined using carbon stable-isotope ratios (δ(13)C). δ(13)C values of mysids, which are the most important prey items for this species, were consistently enriched in the lower estuary and surf zone (LES), while depleted in the freshwater zone (FW). δ(13)C values of juveniles in LES were enriched, while those in FW were depleted, consistent with the δ(13)C difference in prey items. The results of δ(13)C showed that many juveniles migrated upstream from April to June and most of them stayed in FW until at least July. Juveniles that stayed in FW and LES for a relatively longer period (> c. 20 days) showed higher condition factors than those that stayed in FW for a short period (several days). This indicates that residence in FW enabled juveniles to achieve as good a body condition as residence in LES.

Observation of few-cycle, strong-field phenomena in surface plasmon fields

We present experimental evidence of the generation of few-cycle propagating surface plasmon polariton wavepackets. These ultrashort plasmonic pulses comprised of only 2-3 field oscillations were characterized by an autocorrelation measurement based on electron photoemission. By exploiting plasmonic field enhancement, we achieved plasmon-induced tunnelling emission from the metal surface at low laser intensity, opening perspectives for strong-field experiments with low pulse energies. All-optical electron acceleration up to keV kinetic energy is also demonstrated in these surface-confined, few-cycle fields with only 1.35×10(12) W/cm2 focused laser intensity. The experimental results are found to be in excellent agreement with the model.

A dose-ranging study evaluating the oral factor Xa inhibitor edoxaban for the prevention of venous thromboembolism in patients undergoing total knee arthroplasty

BACKGROUND

Edoxaban (the free base of DU-176b) is an oral, direct factor (F)Xa inhibitor in clinical development for the prevention and treatment of thromboembolic events.

OBJECTIVES

The aim of the present study was to evaluate the efficacy and safety of edoxaban for the prevention of venous thromboembolism (VTE) in patients undergoing total knee arthroplasty (TKA).

PATIENTS/METHODS

This was a randomized, double-blind, placebo-controlled, multicenter study conducted in Japan. A total of 523 Japanese patients were assigned to receive edoxaban 5, 15, 30 or 60 mg once daily or placebo for 11-14 days. A placebo control was used as neither low-molecular-weight heparin (LMWH) nor fondaparinux had been approved for thromboprophylaxis at the time of the study in Japan. The primary efficacy outcome was the incidence of VTE (lower-extremity deep vein thrombosis, symptomatic pulmonary embolism or symptomatic deep vein thrombosis). The primary safety outcome was the incidence of major and clinically relevant non-major bleeding.

RESULTS

Edoxaban produced a significant dose-related reduction in VTE: the incidence of VTE was 29.5%, 26.1%, 12.5% and 9.1% in the edoxaban 5-, 15-, 30- and 60-mg treatment groups vs. 48.3% in the placebo group. The incidence of major and clinically relevant non-major bleeding was similar across all groups without any significant differences among edoxaban doses or between edoxaban and placebo.

CONCLUSIONS

Edoxaban demonstrated significant dose-dependent reductions in VTE in patients undergoing TKA with a bleeding incidence similar to placebo. [This trial is registered with JAPIC, JapicCTI-060283 (ja).].

Spectral phase transfer to ultrashort UV pulses through four-wave mixing

Transfer of spectral phase from near infrared ultrashort pulses to deep ultraviolet (UV) sub-30-fs pulses through four-wave mixing process is demonstrated. Micro joule UV pulses at 237 nm were generated by nonlinear mixing of second harmonic pulses of Ti:sapphire laser output and near infrared pulses from a noncollinear optical parametric amplifier. Chirp of the near infrared pulse was transferred to the UV pulse with the opposite sign. A positively chirped near infrared pulse was used for generating a negatively chirped UV pulse, which was compressed down to 25 fs by a magnesium fluoride window.

Potential risk of thermal damage to cervical nerve roots by a high-speed drill

Using the transverse processes of fresh porcine lumbar spines as an experimental model we evaluated the heat generated by a rotating burr of a high-speed drill in cutting the bone. The temperature at the drilled site reached 174 degrees C with a diamond burr and 77 degrees C with a steel burr. With water irrigation at a flow rate of 540 ml/hr an effective reduction in the temperature was achieved whereas irrigation with water at 180 ml/hr was much less effective. There was a significant negative correlation between the thickness of the residual bone and the temperature measured at its undersurface adjacent to the drilling site (p < 0.001). Our data suggest that tissues neighbouring the drilled bone, especially nerve roots, can be damaged by the heat generated from the tip of a high-speed drill. Nerve-root palsy, one of the most common complications of cervical spinal surgery, may be caused by thermal damage to nerve roots arising in this manner.

Laminoplasty for patients aged 75 years or older with cervical myelopathy

PURPOSE

To assess the neurological and walking status of 56 elderly patients after cervical myelopathy to determine whether the surgery was justified.

METHODS

Records of 23 men and 33 women aged 75 to 86 (mean, 79) years who underwent laminoplasty for cervical myelopathy were retrospectively reviewed. They had been followed up for a mean of 3.5 (range, 0.2-8.6) years. Walking status was assessed according to long-term care insurance criteria. In 45 patients with more than 2 years of follow-up, neurological status was evaluated according to the Japanese Orthopaedic Association (JOA) score. Neurological recovery rate was classified as excellent, good, fair, poor, and worse.

RESULTS

Postoperatively, of the 47 patients still living, 22 could walk independently, 22 required assistance outdoors, 2 were using a wheelchair, and one was bedridden. The mean JOA score was 9.7 preoperatively, 12.2 one year postoperatively, and 11.8 at final assessment (p<0.001). The mean neurological recovery rate was 29% at one-year follow-up and 24% at final assessment (p=0.06).

CONCLUSION

Although excellent results were not expected in elderly patients, surgery to maintain independent walking status was justified in most of our patients.

The post-operative changes in the level of inflammatory markers after posterior lumbar interbody fusion

Inflammatory markers such as the C-reactive protein (CRP), white blood cell count and body temperature are easy to measure and are used as indicators of infection. The way in which they change in the early post-operative period after instrumented spinal surgery has not been reported in any depth.

We measured these markers pre-operatively and at one, four, seven and 14 days postoperatively in 143 patients who had undergone an instrumented posterior lumbar interbody fusion.

The CRP proved to be the only sensitive marker and had returned to its normal level in 48% of patients after 14 days. The CRP on day 7 was never higher than that on day 4. Age, gender, body temperature, operating time and blood loss were not related to the CRP level. A high CRP does not in itself suggest infection, but any increase after four days may presage infection.

Risedronate reduces postoperative bone resorption after cementless total hip arthroplasty

Forty-three patients who had undergone cementless THA were randomly assigned to receive no osteoactive drug or oral risedronate for 6 months. Postoperative decrease of BMD in the risedronate group was significantly lower than that seen in the control group in zones 1, 2, 3, 6, and 7.

INTRODUCTION

Proximal bone resorption around the femoral stem often has been observed after total hip arthroplasty (THA), could lead to late stem loosening. We previously reported the efficacy of etidronate on periprosthetic bone resorption after cementless THA. Recently risedronate is suggested to be effective for the prevention and treatment of for osteoporosis. The purpose of the present study was to evaluate the effects of risedronate on periprosthetic bone loss after cementless THA.

METHODS

Forty-three patients who had undergone cementless THA were randomly assigned to receive no osteoactive drug (21 patients) or oral risedronate 2.5 mg/day (22 patients) for 6 months. Three patients were eliminated from the risedronate group because of dyspepsia. Periprosthetic bone mineral density (BMD) in seven regions of interest based on the zones of Gruen et al. was measured with dual energy X-ray absorptiometry at 3 weeks and 6 months postoperatively.

RESULTS

At 6 months after surgery, postoperative decrease of BMD in the risedronate group was significantly lower than that seen in the control group in zones 1, 2, 3, 6, and 7 (p < 0.05, p < 0.01, p < 0.01, p < 0.05, and p < 0.05, respectively).

CONCLUSION

These outcomes suggested that risedronate might reduce the periprosthetic bone resorption after cementless THA.

Widely tunable soliton frequency shifting of few-cycle laser pulses

Photonic-crystal fibers are employed to demonstrate widely tunable frequency down-conversion of unamplified 6-fs Ti:sapphire laser pulses through the soliton self-frequency shift induced by the Raman effect. Wavelength shifts as large as 500 nm are achieved for input few-cycle pulses with broadband spectra centered at approximately 820 nm. The central wavelength of the redshifted output of a photonic-crystal fiber is smoothly tuned from the low-frequency edge in the spectrum of the 6-fs Ti:sapphire laser pulse up to 1.35 microm by varying the input energy in the fundamental mode of the fiber.

Diffraction-arrested soliton self-frequency shift of few-cycle laser pulses in a photonic-crystal fiber

The balance between diffraction and index-step guiding in photonic-crystal fibers is controlled by modifying the fiber structure, leading to different wavelength dependences of the effective mode area and providing a mechanism to control nonlinear-optical phenomena. In optical fibers with a steep profile, the guided mode of the light field tends to become much less compact with an increase in radiation wavelength, slowing down the Raman-induced soliton self-frequency shift of an ultrashort laser pulse. A reduction of the soliton self-frequency shift is demonstrated for input laser pulses.

Parametric amplification of few-cycle carrier-envelope phase-stable pulses at 2.1 microm

We demonstrate an optical parametric chirped-pulse amplifier producing infrared 20 fs (3-optical-cycle) pulses with a stable carrier-envelope phase. The amplifier is seeded with self-phase-stabilized pulses obtained by optical rectification of the output of an ultrabroadband Ti:sapphire oscillator. Energies of -80 microJ with a well-suppressed background of parametric superfluorescence and up to 400 microJ with a superfluorescence background are obtained from a two-stage parametric amplifier based on periodically poled LiNbO3 and LiTaO3 crystals. The parametric amplifier is pumped by an optically synchronized 1 kHz, 30 ps, 1053 nm Nd:YLF amplifier seeded by the same Ti:sapphire oscillator.

Pulse compression with time-domain optimized chirped mirrors

Dispersive optical interference coatings (chirped mirrors - CMs) are designed by computer optimization of an analytically calculated initial multilayer. Traditionally, the relevant properties of the CM (reflectance and the frequency-dependence of the phase shift upon reflection) are optimized to match frequency-domain targets. We propose a novel target function that quantifies directly the capability of a multilayer to control the temporal shape of the reflected optical pulse. Employing this time-domain analysis/optimization one can design dispersive multilayers having air as medium of incidence and supporting the generation of pulses with durations in the sub-5-fs-range, as demonstrated in a proof-of-principle compression experiment.

Nonlinear-optical spectral transformation of few-cycle laser pulses in photonic-crystal fibers

Photonic-crystal fibers with special dispersion profiles are shown to provide a high efficiency of spectral transformation of chirped sub-6-fs Ti:sapphire laser pulses. With the wavelength of zero group-velocity dispersion of the fiber lying within the broad spectrum of the input few-cycle pulse, the output spectra feature well-resolved spectral peaks, indicative of soliton self-frequency shift, four-wave mixing, and Cherenkov emission of dispersive waves. We demonstrate that up to 3% of radiation energy at the output of the fiber can be confined within a spectrally isolated soliton peak centered at , which is ideally suited as a seed for Nd:YAG- and ytterbium-based laser devices.

Soliton-based pump-seed synchronization for few-cycle OPCPA

We demonstrate a significant simplification of the scheme for few-cycle Optical Parametric Chirped Pulse Amplification (OPCPA) which results in the elimination of a picosecond's master oscillator and electronic synchronization loops. A fraction of a broadband seed pulse centered at 760 nm from a 70-MHz Ti:sapphire oscillator was frequency-shifted in a photonic crystal fiber to enable synchronized seeding of a picosecond's Nd:YAG pump laser. The seed radiation at 1064 nm is produced in the soliton regime which makes it inherently more intense and stable in comparison with other methods of frequency conversion. The remaining fraction of the Ti:sapphire output is amplified with a FWHM bandwidth of 250 nm in a single timing-jitter-free OPCPA stage. Our work opens up the exciting possibility to use sub-picosecond's pump pulses from highly efficient Yb-based amplifiers for jitter-less parametric amplification of carrier-envelope phase stabilized pulses from Ti:sapphire oscillators.

Multimillijoule chirped parametric amplification of few-cycle pulses

The concept of optical parametric chirped-pulse amplification is applied to attain pulses with energies up to 8 mJ and a bandwidth of more than 100 THz. Stretched broadband seed pulses from a Ti:sapphire oscillator are amplified in a multistage noncollinear type I phase-matched beta-barium borate parametric amplifier by use of an independent picosecond laser with lock-to-clock repetition rate synchronization. Partial compression of amplified pulses is demonstrated down to a 10-fs duration with a down-chirped pulse stretcher and a nearly lossless compressor comprising bulk material and positive-dispersion chirped mirrors.

Chirped-pulse oscillators: a route to high-power femtosecond pulses without external amplification

We demonstrate a Kerr-lens mode-locked Ti:sapphire oscillator that generates 130-nJ, 26-fs and 220-nJ, 30-fs pulses at a repetition rate of 11 MHz. The generation of stable broadband, high-energy pulses from an extended-cavity oscillator is achieved by the use of chirped multilayer mirrors to produce a small net positive dispersion over a broad spectral range. The resultant chirped picosecond pulses are compressed by a dispersive delay line that is external to the laser cavity. The demonstrated peak powers, in excess of 5 MW, are to our knowledge the highest ever achieved from a cw-pumped laser and are expected to be scalable to tens of megawatts by an increase in the pump power and (or) a decrease in the repetition rate. The demonstrated source permits micromachining of any materials under relaxed focusing conditions.

Observation of ultrahigh-energy electrons by resonance absorption of high-power microwaves in a pulsed plasma

The interaction of high power microwave with collisionless unmagnetized plasma is studied. Investigation on the generation of superthermal electrons near the critical layer, by the resonance absorption phenomenon, is extended to very high microwave power levels (eta=E(2)(0)/4 pi n(e)kT(e) approximately 0.3). Here E0, n(e), and T(e) are the vacuum electric field, electron density, and electron temperature, respectively. Successive generation of electron bunches having maximum energy of about 2 keV, due to nonlinear wave breaking, is observed. The electron energy epsilon scales as a function of the incident microwave power P, according to epsilon proportional to P0.5 up to 250 kW. The two-dimensional spatial distribution of high energy electrons reveals that they are generated near the critical layer. However, the lower energy component is again produced in the subcritical density region indicating the possibility of other electron heating mechanisms.

Deep venous thrombosis after posterior spinal surgery

STUDY DESIGN

A prospective clinical study using venography to evaluate deep venous thrombosis after posterior spinal surgery.

OBJECTIVES

To demonstrate the prevalence of deep venous thrombosis after posterior spinal surgery with no prophylaxis.

SUMMARY OF BACKGROUND DATA

There have been few studies about the occurrence of deep venous thrombosis after spinal surgery in which venography was used for screening.

METHODS

Of the enrolled 134 patients undergoing posterior spinal surgery, 110 (82.1%) were examined with complete surveillance for deep venous thrombosis by venography. There were 64 males and 46 females. The average age at operation was 59.0 years (range, 14-86 years). The levels of the operation were cervical in 54, thoracic in 7, and lumbar in 49. All procedures were performed with patients under general anesthesia. Neither mechanical methods nor anticoagulation medications were used for prophylaxis against thromboembolism. Bilateral ascending venography was performed within 14 days after surgery.

RESULTS

There were no patients with clinical signs of deep venous thrombosis and pulmonary embolism. However, 17 patients (15.5%) showed venographic evidence of deep venous thrombosis, of whom 16 had distal thrombi, and only one had a proximal thrombus. Deep venous thrombosis was venographically evident in 3 (5.6%) of 54 patients who underwent cervical procedures, and it was evident in 13 (26.5%) of 49 patients who underwent lumbar procedures. This difference was statistical significant (chi2 test, P = 0.003). Statistical comparison between patients who did and did not have deep venous thrombosis showed that age was statistically significant (Mann-Whitney test; P < 0.05).

CONCLUSIONS

The prevalence of deep venous thrombosis after posterior spinal surgery is higher than generally recognized. Therefore, further study is necessary to clarify the appropriate method for screening and the effect of prophylaxis against thromboembolism after spinal surgery.

Accuracy of atlantoaxial transarticular screw insertion

STUDY DESIGN

The accuracy and safety of atlantoaxial transarticular screw insertion were evaluated in clinical cases.

OBJECTIVES

To evaluate the accuracy and safety of atlantoaxial transarticular screw insertion under lateral fluoroscopic monitoring without opening the joint.

SUMMARY OF BACKGROUND DATA

Atlantoaxial transarticular screw fixation has been reported to be biomechanically superior to posterior atlantoaxial wiring techniques. Several clinical series have been reported in the literature. In some reports, the risk of screw insertion in this technique has been pointed out.

MATERIALS AND METHODS

Fifty-six consecutive patients with atlantoaxial instability were treated by transarticular screw fixation. One hundred twelve screw insertions in these 56 patients were assessed by surgical record and computed tomographic examination. One screw could not be inserted because of the difficulty of adequate placement during operation; 111 screws were therefore inserted. Adequate position was defined as when the screw perforated the lateral atlantoaxial joint.

RESULTS

In this series, neither vertebral artery injury nor spinal cord injury was experienced clinically. One guide wire was broken during drilling with a cannulated drill. Computed tomographic examination demonstrated that 106 screws perforated the atlantoaxial joint. Therefore, 95.5% of screws were adequately positioned. There were two screws positioned lateral to the joint, two medially, and one anteroinferiorly to the joint.

CONCLUSIONS

Atlantoaxial transarticular screw insertion using image intensifier without opening the lateral joint was performed safely, but not accurately, in all cases.

Deep venous thrombosis after total hip or total knee arthroplasty in patients in Japan

A single center, prospective, epidemiologic study was conducted to estimate the incidence of deep venous thrombosis detected by venography in patients in Japan undergoing total hip arthroplasty or total knee arthroplasty without prophylactic anticoagulant therapy. Venograms of 164 patients who had total hip arthroplasty and 138 patients who had total knee arthroplasty were evaluated. The incidences of deep venous thrombosis were 22.6% in patients who had total hip arthroplasty and 48.6% in those who had total knee arthroplasty. The incidences of proximal deep venous thrombosis were 9.8% in patients who had total hip arthroplasty and 14.5% in those who had total knee arthroplasty. Statistical analysis revealed that the type of operation influenced the development of deep venous thrombosis. Patients who had total knee arthroplasty were 3.2 times more likely to have deep venous thrombosis develop than were patients who had total hip arthroplasty. Body mass index and age were identified as statistically significant risk factors.

A survey of autologous blood collection and transfusion in Japan in 1997

BACKGROUND

In spite of the fact that autologous blood is safest for a patient to receive, it is not generally appreciated that adverse reactions during donation and transfusion may occur. This study was conducted to assess the state and the risk of autologous blood transfusion in Japan in 1997.

STUDY DESIGN AND METHODS

Results of a nation-wide questionnaire-based survey are presented. The questionnaire assessed the number of autologous blood donations, donation procedures, and the adverse reactions associated with donation, preservation, recombination erythropoietin administration and transfusion.

RESULTS

Between November 1996 and October 1997, 10,697,000 ml (or 53,485 units, 200 ml = 1 unit) prestorage blood donation were made by 14,200 patients (averages; 1.9 donations/patient, 753 ml/patient, 398 ml/donation). Of these, 87% were transfused to the patients and the remainder were discarded. Using hemodilution and blood salvage intra- or postoperatively some 2,540,000 ml of blood was collected and > 70% of patient-donors received such blood. Adverse reactions were observed with 1.6% (428/26,905) of donations including 6 angina and 2 asthma attacks. There were 63 (0.2%) problems with 28,705 donations and 117 (0.5%) errors/problems reported for 24,929 units transfused; the most frequent problems were clotting on the units and breakage of the bags during storage. Hypotension using hemodilution (3.7%), coagulation (0.9%) or bacterial contamination (0.4%) using salvage were often observed. A 10-20 ml volume of autologous fresh-frozen plasma was transfused to the wrong recipient.

CONCLUSION

Autologous blood transfusion accounts for at least 1.1% (2.8% estimated) of the red cell supply in Japan. Errors and adverse reactions are not infrequent in autologous blood programmes. By introducing systematic safety policies, we will be able to make autologous blood transfusion safer.

Spinal intramedullary ependymal cyst: a case report

BACKGROUND

Spinal intramedullary ependymal cysts are extremely rare. Only seven pathologically proven cases have been reported in the literature.

METHOD

We present an 18-month-old female with thoracic spinal intramedullary ependymal cyst that was diagnosed pathologically.

RESULTS

Histological diagnosis was made by light microscopy after immunostaining. After partially removing the cyst wall and establishing communication between the cyst and the subarachnoid space, the patient improved neurologically.

CONCLUSIONS

For spinal intramedullary ependymal cyst we recommend diagnosis by MR imaging without myelography, then enucleation of the cyst, if possible. Otherwise, we remove the cyst wall as much as possible and create adequate communication between the cyst and the subarachnoid space.

Complications following metatarsal lengthening by callus distraction for brachymetatarsia

We performed six metatarsal lengthenings in four patients for brachymetatarsia of the fourth toe by callus distraction from 1991 to 1995. Healing was achieved in all cases. The average amount of lengthening was 30% (range, 15-41%) of the original length. The average healing index was 82 days/cm (range, 66-113 days/cm). After the operation, range of movement of the metatarsophalangeal joint decreased in all cases (120 degrees before and 57 degrees after surgery). In two cases in which the lengthening exceeded 40% of the original length, stiffness of the joint (20 degrees and 0 degrees each) and joint deformity occurred. These two cases also had angulation of the metatarsal. Corrective osteotomy and release surgery was performed in one case. Angulation of the metatarsal was corrected, but the range of movement of the joint did not much recover after surgery. Another case was left untreated because the patient had no complaints. In metatarsal lengthening by callus distraction, the amount of lengthening should not exceed 40% of the original length.

Long-term follow-up results of laminectomy for cervical myelopathy caused by ossification of the posterior longitudinal ligament

OBJECT

This retrospective study was performed to assess the long-term results of cervical laminectomy in treating ossification of the posterior longitudinal ligament (OPLL) of the cervical spine.

METHODS

The authors reviewed medical records in 44 of 52 patients who underwent cervical laminectomy between 1970 and 1985 (mean follow up 14.1 years). The neurological recovery rate after laminectomy was 44.2% after 1 year and 42.9% after 5 years. The surgical outcome was maintained after 5 years but worsened between 5 and 10 years postsurgery: the recovery rate at the last follow-up review was 32.8%. Using multivariate stepwise analysis, the preoperative factors that affected clinical results were found to be the age at operation, the severity of preexisting myelopathy, and a history of trauma. Late neurological deterioration was observed in 10 (23%) of 44 patients. The earliest deterioration occurred at 1 year and the latest was at 17 years postsurgery (mean 9.5 years). The most frequent cause of deterioration was trauma due to a fall (six patients), followed by ossification of the ligamentum flavum (three patients). Postoperative spread of the OPLL was noted in 70% of the patients, but it was clearly the cause of neurological deterioration in only one of them. After laminectomy, postoperative progression of kyphotic deformity was observed in 47% of patients, but these changes did not cause neurological deterioration.

CONCLUSION

The authors recommend early surgical decompression for OPLL because the outcome is better for younger patients and for those with a higher score as measured by the Japanese Orthopedic Association's system.

Intradural spinal hibernoma: case report

BACKGROUND

Hibernoma is a rare, benign tumor arising from vestigial remnants of brown adipose tissue. It usually affects muscle and subcutaneous tissue and is asymptomatic and slow growing.

METHODS

A review of the worldwide literature contains about 110 cases of hibernomas. However, only two cases (including our case) of hibernoma located in the intradural spine have been reported. We present an extremely rare case of intradural extramedullary spinal hibernoma and summarize the magnetic resonance imaging (MRI) findings of the lesion.

CASE DESCRIPTION

A 35-year-old woman suffered from motor weakness and numbness of the left upper extremity. Cervical spinal MRI revealed an intradural extramedullary mass at C7. She underwent surgery via the posterior approach and the lesion was completely removed. Histopathologic examination showed multivacuolated cells with centrally placed nuclei, and the diagnosis of hibernoma was made.

CONCLUSIONS

Because the CT and MRI findings of hibernoma are almost same as those of other lipomatous tumors, a surgical specimen of this tumor is necessary to establish the correct diagnosis. Early diagnosis and total resection are necessary as some cases showed malignant features or rapid growth. Etiologically, the tumor may have developed by the ectopic growth or migration of adipose tissue.

Application of synchrotron radiation to ultrafast spectroscopy

A novel application of synchrotron radiation to ultrafast optical spectroscopy is demonstrated. The application is based on the short coherence time of broadband synchrotron radiation and employs a conventional interferometer. From a detailed study of the coherence of synchrotron radiation, it is shown that the coherent interference between two synchrotron radiation beams, split from a single beam, can provide ultimate time resolution down to a few femtoseconds. Experimental results of ultrafast spectroscopy using broadband synchrotron radiation are presented; these include free-induction decay and photon echoes in the visible and ultraviolet regions.

Ectopic bone formation after total hip arthroplasty

Two hundred and forty consecutive Japanese patients with 280 primary total hip arthroplasties (THA) were analyzed to clarify the incidence of ectopic bone formation and its predisposing factors and to examine its effect on the clinical results. Ectopic bone formation after THA was found in 61 joints (22%). The predisposing factors were male patients and a hypertrophic type of osteoarthritis. It was revealed that extensive ectopic bone formation, class 3 according to Brooker's classification, restricted flexion and abduction motion of the hip joint.

Flexor tendon ruptures caused by an intraosseous ganglion of the hook of the hamate

A rare case of pathological rupture of the flexor tendons of the small finger caused by an intraosseous ganglion of the hook of the hamate is described.

Sclerosis of lytic metastatic bone lesions during treatment with pamidronate in a patient with adenocarcinoma of unknown primary site

Pamidronate disodium is a second-generation biphosphonate, a group of compounds that are being used increasingly to inhibit bone resorption in disorders that are characterized by excessive bone loss such, as hypercalcemia of malignancy, osteoporosis, and Paget's disease. The precise mechanisms whereby bisphosphonates inhibit bone resorption are still not completely understood. Pamidronate has previously been reported to induce sclerosis of lytic bone metastases in patients with breast cancer. We have had a similar experience in a patient with multiple bone metastases due to adenocarcinoma of unknown primary site who developed massive consolidation of lytic bone lesions after therapeutic infusions of pamidronate, leading to a satisfactory quality of life.

Cervical ventral epithelial cyst treated by anterior corpectomy--case report

A 15-year-old boy presented with a cervical ventral epithelial cyst manifesting as intractable cervical pain. Neurological examination revealed weakness of his left grasp and increased deep tendon reflexes. The anterior approach was selected because the lesion was located directly ventral to the spinal cord. He underwent C4-5 anterior corpectomy and subtotal resection of the cyst wall. He made a good recovery without additional deficits. Most previously reported cases have been treated using the posterior approach despite the ventral location of the lesion. The anterior approach offers a safer and more effective means of treating such lesions because it allows direct access to the lesion without manipulation of the spinal cord.

Vertebral body replacement with a ceramic prosthesis for metastatic spinal tumors

STUDY DESIGN

This study retrospectively analyzed the clinical outcome of vertebral replacement surgery with our unique ceramic prosthesis for spinal metastases.

OBJECTIVES

To indicate the results of vertebral replacement surgery with a ceramic prosthesis.

SUMMARY OF BACKGROUND DATA

Spinal metastasis often involves the vertebral bodies, of which abnormal fracture causes intractable pain and paresis. For such conditions, laminectomy or irradiation can have no effect because they do not improve spinal stability. Autogenous bone or bone cement are not durable materials, and fatigue fracture of the implanted material occasionally occurs. We developed a simple prosthesis made of alumina ceramic, a bioinert material, to replace the affected vertebrae. There has not been such a large study to assess vertebral replacement surgery with a ceramic prosthesis.

METHODS

From 1972 to 1993, 90 ceramic prostheses were used in 84 patients with spinal metastasis, and the average follow-up period was 26.2 months. The primary tumor was thyroid cancer in 13 patients, breast cancer in 12, multiple myeloma in eight, renal cell cancer in eight, gastrointestinal cancer in eight, and lung cancer in eight. The clinical symptoms were assessed before and after surgery, and the maintenance of operative gain was investigated.

RESULTS

Pain relief was achieved in 94%, motor function improved in 81%, and ambulation recovered in 64%. There were no serious complications associated with the procedure, and the operative benefit was maintained until the terminal stage in the vast majority of patients.

CONCLUSIONS

In selected patients, vertebral replacement using our prosthesis proved to be a useful procedure, effectively managing the severe spinal pain or neurologic deficits associated with vertebral body destruction.