Introduction: We have calculated the amount of antero-posterior diameter expansion by tibial intramedullary nails with distal anterior bend which were designed to prevent proximal posterior cortical fracture by the distal tip of a nail on insertion in the surgical treatment of tibial fracture. Materials and Methods: Russell-Taylor® and AIM™ tibial nails were compared in respect to the amount of anteroposterior diameter expansion by the distal anterior bend of these nails. AIM™ tibial nails have shorter length but larger angle of distal anterior bend than Russell-Taylor® tibial nails. As Fig.1. shows, if we suppose that the length and angle of distal anterior bend of nail be L and _, respectively and the length of distal tapered portion be T, the amount of anteroposterior diameter expansion (E) by the distal anterior bend portion of the nail is [(L-T) _ sin_]. So, intramedullary nail with distal anterior bend passes down the medullary canal with an actual diameter (AD) of the sum of given diameter of the nail (D) and [(L-T) _ sin_] on anteroposterior plane. Results: The amount of anteroposterior diameter expansion of Russell-Taylor® and AIM™ tibial nail was 2.81 mm and 3.26 mm more than the given nail diameter because the length and angle of distal anterior bend of Russell-Taylor® and AIM™ tibial nails were 64 mm, 3° and 47.5 mm, 5°, respectively and about 10 mm of distal tip of both nails are tapered to facilitate passage in the medullary canal. Conclusion: On insertion of tibial nails with distal anterior bend, the anteroposterior diameter expansion effect by these nails should be carefully considered to prevent fracture of the isthmus. We think that the nail about 2 to 3 mm smaller than the final reamer used in diameter had better be used when you try to insert an intramedullary nail bent anteriorly at distal portion such as Russell-Taylor® and AIM™ tibial nails

Purpose: To evaluate the normal glenoid size of the Koreans in their 7th and 8th decades with the Computed tomographic (CT) studies.

Materials and Methods: The CT images were obtained from normal scapulae of the patients (mean age : 68.8, range 62–76) with the humeral fracture cases. A Display workstation version 2.0.73.315 was used to measure the scans to determine the maximal superoinferior(SI) and anteroposterior(AP) diameter of the osseous glenoid vault.

Results: The average diameter of curvature of the glenoid were 31.2±2.3mm(range, 27 to 34mm) in the superior-inferior directions and 26.1±2.4mm(range, 22 to 31mm) in anterior-posterior.

Conclusion: This study showed the normal glenoid size of the Korean and it is smaller than the size which the international literature reported. It would be important factor for the treatment of fracture or arthroplasty implant designs.

Objects: We have studied knee morphology using 3DCT considering the bone cutting surface in Total Knee Arthroplasty (TKA in Japan. Subjects were 50 knees in 49 with knee disorders, consisting of 20 knees in 20 men and 30 knees in 29 women. The age range was 16–77 year old (the mean age 52.2). Method: The image of a patient’s knee joint was taken by three-dimensional perspective imaging device (SIEMENS, ARCADIS) before surgery, and it was structured with the three-dimensional computer software K.G.T, INTAGE Realia Professional to measure the knee joint configuration. In the measured site with assumption of the bone cutting surface of the femur side in TKA, the valgus angle of femur was °to the bone axis and the maximum transverse diameter and the maximum anteroposterior diameter of the external condyle were measured at the femur side 8 mm proximal to the external condyle, and the tibial side was vertical to the bone axis and the maximum anteroposterior diameter of the internal and external condyles were measured at the tibial side 2 mm distal to the interior joint surface. The ratio of the anteroposterior diameter and the transverse diameter was computed by these measurements. Result: The average measurements of the femur were 70.82mm of the transverse diameter, 51.2mm of the anteroposterior diameter, and 0.73 of the ratio of the anteroposterior diameter and the transverse diameter. The average measurements of the tibia were 72.5mm of the transverse diameter, 54.4mm of the anteroposterior diameter of the interior condyle, 46.7mm of the anteroposterior diameter of the exterior condyle, and 0.75 and 0.64 of the ratio of the anteroposterior diameter and the transverse diameter of the interior and exterior condyles, respectively. The measurements of the femur were bigger in any sites of men than women, and the transverse diameter was bigger, the anteroposterior diameter tended to be smaller. The transverse diameter did not clearly correlate with the ratio of the anteroposterior diameter and the transverse diameter at the tibial side, and different correlations were shown between men and women respectively. Discussion: At the femur side, a Japanese knee was flatter than a Westerner’s knee just like the previous reports in Japan. The knee is bigger, the knee tends to become flatter, and men are more likely to have the tendency than women. At the tibia side, there were differences for correlation of the flat level between men and women, and it suggested the potential sex difference. Conclusion: The measurement with 3DCT is easy-to-use, and the variation is small compared to an actual measurement value. We want to put it to use for implant design in references to these measurements for the future

Aims. Developmental cervical spinal stenosis (DcSS) is a well-known predisposing factor for degenerative cervical myelopathy (DCM) but there is a lack of consensus on its definition. This study aims to define DcSS based on MRI, and its multilevel characteristics, to assess the prevalence of DcSS in the general population, and to evaluate the presence of DcSS in the prediction of developing DCM. Methods. This cross-sectional study analyzed MRI spine morphological parameters at C3 to C7 (including anteroposterior (AP) diameter of spinal canal, spinal cord, and vertebral body) from DCM patients (n = 95) and individuals recruited from the general population (n = 2,019). Level-specific median AP spinal canal diameter from DCM patients was used to screen for stenotic levels in the population-based cohort. An individual with multilevel (≥ 3 vertebral levels) AP canal diameter smaller than the DCM median values was considered as having DcSS. The most optimal cut-off canal diameter per level for DcSS was determined by receiver operating characteristic analyses, and multivariable logistic regression was performed for the prediction of developing DCM that required surgery. Results. A total of 2,114 individuals aged 64.6 years (SD 11.9) who underwent surgery from March 2009 to December 2016 were studied. The most optimal cut-off canal diameters for DcSS are: C3 < 12.9 mm, C4 < 11.8 mm, C5 < 11.9 mm, C6 < 12.3 mm, and C7 < 13.3 mm. Overall, 13.0% (262 of 2,019) of the population-based cohort had multilevel DcSS. Multilevel DcSS (odds ratio (OR) 6.12 (95% CI 3.97 to 9.42); p < 0.001) and male sex (OR 4.06 (95% CI 2.55 to 6.45); p < 0.001) were predictors of developing DCM. Conclusion. This is the first MRI-based study for defining DcSS with multilevel canal narrowing. Level-specific cut-off canal diameters for DcSS can be used for early identification of individuals at risk of developing DCM. Individuals with DcSS at ≥ three levels and male sex are recommended for close monitoring or early intervention to avoid traumatic spinal cord injuries from stenosis. Cite this article: Bone Joint J 2024;106-B(11):1333–1341

Purpose: Implantation of a prosthesis on a remodelled femur can cause technical difficulties affecting the outcome of the arthroplasty. We performed a tridimensional study of the femoral anatomy before prosthesis implantation for sequelar congenital hip dislocation. Material and method: The series included 312 hips in 262 patients. The same radiography and computed tomography work-up was perfomred in all patients. There were 288 women and 84 men, men age 56 years. Mean weight was 66 kg and mean height was 163 cm. The crowe classification was 195 dysplasia, 123 dislocations (41% class I, 27% class II, 13% class III, 19% class IV). Telemetric measurements were: femoral isthma, the centre of the lesser trochanter, limb length discrepancy, the cephalo-cervico-diaphyseal angle. Computed tomographic measurements were: anterio-posterior and mediolateral dimensions and femur funneling, helitorsion between the bichondylar plane and the upper femur, anteroposterior diameter of the acetabulum. Results: The mean mediolateral and anteroposterior diameters of the femoral canal at the isthma were 9.8 and 13.1 cm respectively in dysplasia and 9.3 and 12.6 cm, 9.4 and 12.7, and 9.7 and 13.6 cm in I, II, and III–IV congenital dislocations respectively. The femoral funneling index varied from 1.9 to 7.6 in dysplasia and from 2.6 to 7.9, 2.1 to 8.4 and 2.1 to 8.7 in I, II, and III–IV congenital dislocations respectively. The mean cephalo-cervico-diaphyseal angle was 129.3°, 131.9°, 136.8°, and 127.4° respectively. Maximal leg length discrepancy was 45, 57, 71, and 82 cm respectively. Mean helitorsion was 22.9° (1°–52°), 36.4° (8°–86°), 43.2° (2°–82°- and 38.4° (6°–68°) respectively. The mean anteroposterior diameter of the acetabulum was 52, 51.2, 53.1; and 49.6 cm respectively. Discussion and conclusion: The dysplastic or dislocated femur is narrower than the normal femur with wide variations in funneling and cephalo-cervico-diphyseal angle. The mean difference in leg length increases gradually with helitorsion but with wide individual variability, irrespective of the grade. These tridimensional anatomic data can be useful for predicting difficulties in prosthetic treatment of these patients

Objective. The aim of this study was to evaluate the shape of patella relative to the femoral epicondylar axis and to find sex differences. Materials and methods. Computed tomography (CT) images of 100 knees with tibiofemoral osteoarthritis in 100 patients were prospectively collected. All patients were diagnosed as varus-type osteoarthritis with no destructive patellar deformity. Fifty patients were male and 50 female. The average male age was 70.8±14.6 (mean ± SD) years and the average female age was 73.3±6.7 years. Forty nine knees were right and 51 knees were left. The average height of males was 162.6±7.4 cm and that of females 149.6±5.7 cm. Males were significantly taller than females. The CT scan was performed with 2mm-interval slices in the vertical plane to the long axis of femoral shaft. Every CT image was examined to determine the maximum distance between the medial and lateral femoral epicondyle (inter-epicondylar distance, IED) along the epicondylar axis. The maximum patellar width and thickness were also measured at the image which had these maximum distances, while patellar cartilage thickness in anteroposterior diameter was not measured in this study. For evaluating the patellar size, each measured value was divided by IED and calculated each ratio. The ratio of patellar width to patellar thickness was also calculated. All parameters were compared between males and females. Statistical software Statview ver.5.0 (SAS Institute Inc.) was used for all analyses with significance being set at the 5% level. Results. Measured values are presented on Table 1. The average IED, patellar width and patellar thickness of males were all significantly larger than those of females. As shown in Table 2, by contrast, each ratio to IED was almost the same between the sexes and there were no significant differences. The ratio of patellar width to patellar thickness was 46.7±2.6% in males and 46.6±2.9% in females. Discussion. Although some studies have assessed the actual measurement values of patella, no prior study, to our knowledge, has morphologically evaluated the patella relative to the femur. This is the first study to investigate the configuration and location of patella relative to femoral epicondylar axis. Our results showed the configuration of patella relative to the femoral epicondylar axis was the same between sexes. The patellar width is approximately 56% and TGD is approximately 39% of IED. The most common complications after the surgery are related to patellofemoral problems. The ideal thickness of the resurfaced patella has not been clearly investigated. Patellar disabilities are associated with both decreased and increased patellar thickness— a thin patella could lead to anteroposterior patellar instability and a thick patella could increase the risk of stiffness of the knee and patellar subluxation. Therefore, it is desirable to restore the original patellar thickness during surgery. The results of current study showed that the ratio of patellar width to the patellar thickness was about 47%, which is useful to determine the thickness of patella during surgeries for severely damaged knees or revision surgeries

The major causes of revision total knee are associated with some degree of bone loss. The missing bone must be accounted for to insure success of the revision procedure, to achieve flexion extension balance, restore the joint line to within a centimeter of its previous level, and to assure a proper sizing especially the anteroposterior diameter of the femoral component. In recent years, clinical practice has evolved over time with a general move away from a structural graft with an increase in utilisation of metal augments. Alternatives include cement with or without screw fixation, rarely, with the most common option being the use of metal wedges. With the recent availability of highly porous augments, the role of metal augmentation has increased. Bone graft is now predominantly used in particulate form for contained defects with more limited use of structural graft. The role of the allograft-prosthetic composite has become more limited. For the elderly with osteopenia and massive bone loss, complete metal substitution with an oncology prosthesis has become more common. The degree of bone loss is a major determinant of the management strategy. For contained defects less than 5 mm, cement alone, with or without screw supplementation, may be adequate. For greater than 5 mm, morselised graft is frequently used. For uncontained defects of up to 15 mm or more, metal augmentation is the first choice. Bone graft techniques can be utilised in this setting, however, these are more time consuming and technically demanding with little demonstrated advantage. For larger, uncontained defects, newer generation highly porous augments and step wedges are useful. Large contained defects can be dealt with utilising impaction grafting, similar to the hip impaction grafting technique. Massive distal defects are expeditiously managed with oncology defects in the case of periprosthetic fracture and/or massive osteolysis particularly when combined with osteopenia in an elderly, low demand patient. Surgeons must be familiar with an array of techniques in order to effectively deal with the wide spectrum of bone defects encountered during revision total knee arthroplasty

Purpose: Hip prosthesis for sequelar developmental dysplasia of the hip is a therapeutic challenge because of the anatomic deformity and the young age of the patients. The purpose of this work was to report results obtained using a non-cemented femoral stem with an intramedullar design and a prosthetic neck custom-made to match individual anatomy observed on preoperative computerised tomographic. Material and methods: This study included 257 hips with a mean follow-up of 5.6 years. Mean age at implantation was 55 years (range 17–78). The computed tomography study assessed: dislocation according to Crowe, leg length discrepancy, and acetabular anteversion and diameter. The cup was not cemented and was inserted with an anchor hook in the obturator foramen for implantation in the paleoacetabulum. The medullary canal was prepared using a blunt reamer shaped like the definitive prosthesis. The prosthetic neck was designed individually to match the lever arm and anteverion. Results: There were 174 cases of dysplasia and 83 dislocations (39% grade 1, 30% grade 2, 14% grade 3 and 17% grade 4). Mean lengthening was 39 mm. The mean ante-verion was 28±16° and the mean anteroposterior diameter of the acetabulum was 51 mm. The Harris clinical score improved from 58 points preoperatively to 93 points at last follow-up. The follow-up x-rays showed osteointegration in 88% of the cases with osteolysis in 5% and one stem impaction. The prosthesis had to be changed for six hips: two for infection, one for dislocation and two for nonfixation. The 11-year survival rate was 97%. Discussion and conclusion: This study illustrates the anatomic sequelae observed in patients with developmental dysplasia of the hip and demonstrates a surgical solution for these problems. There is no correlation between dislocation and the degree of anteversion so it is difficult to assess the difficulty of inserting a non-cemented stem without preoperative computed tomography. The good 11-year survival is encouraging for this young and active population

Objectives: To evaluate and compare the imaging of lumbar spinal canal stenosis using plain radiographs, CT-Myelogram and MRI. Patients and Methods: Prospective study at Medical College Calicut during 2002-2004. 25 patients of age from 25 to 69 years, with clinical features of lumbar spinal canal stenosis were evaluated. Inter pedicular distance, anteroposterior diameter and thecal sac cross sectional area (IPD, APD and TSCA) were measured using plain radiographs, CT-Myelogram and MRI, in all 25 patients. Results: Soft tissue compression evaluated as disc protrusion and ligamentum flavum hypertrophy detected in 20 patients by CT-myelography and 22 patients by MRI. Thecal sac cross sectional area at stenosed level were assessed and compared with CT- Myelography and MRI, out of 25 patients 10 and 11 patients were detected with significant narrowing by CT-Myelogra-phy and MRI respectively in which 2 cases of severe thecal sac compromise (< 76 mm2) detected by CT-Myelography and 3 cases by MRI. CT–Myelography detected one case of single level absolute stenosis (AP diameter of < 10mm), but none of the cases were detected by MRI or Plain radiography. Relative stenosis (AP diameter of 10-12mm) at single level detected in 6 cases by CT–Myelography, in 4 cases by MRI and in 3 cases by plain radiography. Relative stenosis at multiple level detected in 3 cases by CT–Myelogra-phy, in 4 cases by MRI and in 6 cases by plain radi-ography.4 cases of multilevel absolute stenosis were detected by all 3 modalities. Conclusions: CT- Myelographic measurement are well correlating with clinical symptoms and MRI findings. Bony Canal measurements obtained by CT- myelogra-phy are superior to same measurements obtained by MRI. Thecal-sac cross sectional area measurements obtained by CT-Myelography is comparable with that of MRI, even though soft tissue involvement in lumbar spinal canal stenosis is more clearly detected by MRI. In comparison of AP diameter taken by plain radiograph and CT- Myelography, X-ray measurements shows only 50-60% accuracy. AP diameter in CT- Myelography and MRI were comparable, when the thecal-sac cross sectional area measured by MRI taken as gold standard (using Karl pearsons correlation coefficients). CT-Myelography shows sensitivity of 92% and specificity of more than 96%

Purpose: Unless exposed to stress, bone undergoes lysis. Osteoconduction is not observed in hydroxyapatite in contact with dead bone. We wanted to know whether bone blocks positioned on metal back cups in patients with total hip arthroplasty for acetabular dysplasia are destroyed lysis or “adhere” to the hydroxyapatite. Material and methods: The series included 22 bone blocks in 21 patients with low weight-bearing displacement (n=10), high weight-bearing displacement (n=6), high non-weight-bearing displacement (n=6). Mean follow-up was six years (17 patients > 5 years). Technique: all blocks were fashioned with autologous bone. The size of the cup, and thus the volume of the bone block, was determined by the largest anteroposterior diameter compatible with the desired position. The block was fashioned with a trial cup in place. The definitive cup was inserted separately then lag screwed to the bone block. Implants: twenty-two titanium cups (3 mm) with hydroxyapatite surfacing, bone block width: approximately 28° from the centre of the prosthetic head. Cup position: native acetabulum (n=11), neoacetabulum (n=11). Results: Complications were : sciatic paresia (n=0), displacement (n=0), shift in cup position (n=1 at day 21). Partial lysis of the bone block was observed but there was no case of total lysis. Titanium-hydroxyapatite-block adhesion: no lucent line was visible in 17 cases at more than five years. There were no cases of bony nonunion. Discussion: Are grafts necessary with a metal back cup? The cup is slightly exposed in some primary degenerative hips but all goes well for ten years without a bone block. At what point would cup “exposure” require a bony support? As autograft material is available, it would appear inappropriate to not use it, especially since the lack of lysis suggests grafts are useful. All bony structures behave in an intelligent manner: an oversized bone block undergoes lysis but the part under stress above the cup becomes more dense. Conclusion: Autologous bone blocks placed on metal back cups are not destroyed by lysis. The bone-hydroxyapatite couple adheres normally. Autologous bone blocks above metal back cups behave intelligently, like blocks inserted above cemented polyethylene cups

Purpose of the study: Idiopathic scoliosis is a tridimensional deformation of the spine. For an overall description of the deformation, it is important to determine the exact deformation in each dimension to identify the topography and amplitude of the curvatures as well as the sagittal balance and vertebral rotation. Scoliosis is actually a deformation of the thoracic cage, which could be considered as its fourth dimension. The purpose of this study was to measure thoracic parameters, particularly thoracic volume, as a function of spinal curvature and growth in children. The goal was to better describe the deformation and difference in comparison with the normal population. Material and methods: In this prospective study, The Orten (Lyon) optical acquisition system was used to fashion a corset for 130 patients (110 girls, 20 boys, aged 4–16 years) with idiopathic scoliosis. The volume, circumference, anteroposterior and frontal diameters as well as the lengths T1–T12 and sternum were noted. These data were confronted with the clinical growth parameters: age, height in the upright and sitting position, body length, body weight, body mass index. Thoracic curvatures were measured using the Cobb system (15–45°). The vertebral rotation component was noted. In order to compare these pathological data with those observed in a normal population, the same optical acquisition protocol was performed in a control group of 65 girls and 61 boys free of thoracic deformation. Results: There was no significant difference in thoracic volume relative to the different growth parameters between the control group and the scoliosis group (Wilcoxon test: p=0.056). There was a correlation between thoracic volume (3–17 dm3) and age: boys r=0.75 and girls r=0.74. At about 4 years, thoracic volume was on average 33% of volume attained at puberty and at 10 years, 55%. These reference points were true for girls and for boys in the scoliosis and the control groups. The following relationships between thoracic measurements and sitting height were found to remain unchanged during growth: frontal diameter is about 30% of sitting height; anteroposterior diameter is equal to the length of the sternum and is about 20% of sitting height. Discussion and conclusion: The Orton optical acquisition system can be used to describe quantitatively the deformation of the thoracic cage caused by scoliosis. There was however no significant difference in thoracic volume between the normal controls and the scoliosis children with a curvature < 45°. Major scoliosis leads to deformation of the vertebral bodies and thus the thorax. This fourth dimension of the deformation should be taken into consideration when establishing the treatment by corset or surgery. This study described the thoracic parameters observed during growth in children with mild to moderate scoliosis. A later study on more severe forms will complete these data and enable an objective assessment of the thoracic deformation

A special surgical technique and consideration is necessary in the total hip arthroplasty for dysplastic osteoarthritis after Kalamchi and MacEwen Type III or IV deformity (so called “Perthes-like-deformity”). There have been few reports concerning the total hip arthroplasty for “Perthes-like-deformity”. We evaluated the clinical and radiological outcome of 52 uncemented hip arthroplasties for the lesion. We have performed 106 hips of uncemented total hip arthroplasty for dysplastic osteoarthritis after Kalamchi and MacEwen Type III or IV deformity. Among them, 52 hips of 47 patients (11 males and 41 females) were evaluated with minimum of three years follow-up. The average age at the surgery was 52 (28 to 65). The average follow-up period was 4.8 (3 to 8.1) years. Against the developmental dysplasia or dislocation, 29 hips of 26 patients had been treated by casting or surgery in infancy. Thirteen hips of 11 patients had no previous treatment before the arthroplasty. Spongiosa metal cup (GHE: ESKA implants, Lübeck, Germany) was used for 33 hips of 28 patients and Zweymüller type cup (Allo-classic cup: Zimmer Inc., Warsaw, IN, Bicon cup: Smith & Nephew Orthopedics AG, Rotkreuz, Switzerland) for 19 hips of 19 patients. Spongiosa Metal stem (GHE: ESKA implants) was used for 23 hips of 19 patients and Zweymüller type stem (Alloclassic stem: Zimmer Inc., SL stem: Smith & Nephew Orthopedics AG) for 29 hips of 28 patients. The average operative time was 108 (53 to 233) minutes. The average blood loss during the surgery was 731(150 to 1749) milliliters. The adductor tendon release was added in 28 hips of 26 patients against the severe contracture. The patients were evaluated clinically (pre-surgical history, hip score, leg length discrepancy, Trendelenburg sign, and gait function) and radiologically (ATD before the surgery, alignment, and stability of implants). Average ATD before the surgery was −2.2 (−28 to 17) millimeters. The average leg length discrepancy was 1.9 (0 to 7) centimeters before the surgery and was improved to 0.1 (0 to 1) centimeters after the surgery. The average hip score was 54 (23 to 80) before the surgery and was improved to 90 (69 to 100) after the surgery. At the final follow-up, Trendelenburg sign was positive in 14 hips of 14 patients (26.9%) and the limping was not obvious in 38 hips of 33 patients (73.1%). All implants were stable at the final follow-up. “Perthes-like-deformity” often has the severe deformity. It has a shortening or an absence of the neck and an excessive antetorsion of the femur. When it has the coxa magna, the acetabulum is shallow, has the narrow anteroposterior diameter, and has the thin wall like the osteophyte. It is frequently accompanied by shortening of leg and contracture, as the lesion arises from the development disorders. Thus, the total hip arthroplasty, especially uncemented one, is complicated. However, the satisfactory result can be obtained by careful consideration and surgical procedure such as a provision against the bleeding and the soft tissue release

The capacity of the lumbar spine canal has direct relation to space-compromising conditions. Primary narrowing of the canal may produce no symptoms, but a slight reduction in capacity as a result of degenerative lesions, age, or disc bulging may result in symptomatic spinal canal stenosis. We studied the dimensions in the adult Greek population in order to find the variability factor in the capacity of the lumbar spinal canal. The dimensions of the lumbar spinal canal were measured in 27 adult men and 42 adult women, all under the age of 50. MRI was used to measure four levels of the spine (L2 through L5). The AP and transverse diameters, as well as the cross section area, were measured at each level. Mean age (sd) of females was 34.8 (6.8) years. Mean age for males was 35.2 (7.3) and was comparable to women (P0.8). Mean age of a third group of 11 males over the age of 50 was 54.5 (2.6). All individuals included in the study were healthy and without any apparent degenerative changes in the lumbar spine or any symptoms related to it. Hotelling’s tests (Anderson, 1958), in terms of multivariate measurements of the spinal canal, were used to compare both genders and the two age levels. Tests for trends in the lumbar levels L2 through L5 were based on the exact binomial distribution for the number of cases exhibiting a complete trend from L2 to L5. The reported significance levels are adjusted for multiplicity of tests. The relation of spinal width to lumbar levels is shown separately for the groups of males and females women under the age of 50 and for the group of males under over the age of 50. In all four lumbar levels, the group of men over 50 years old had a narrower spinal canal compared with men under 50 years old (2=0.005). This was particularly evident in levels L2 and L5 where the spinal canal for older men was narrower by factors of 15.5% and 13.1%, respectively. In the two gender groups of comparable age, spinal width was found to differ between men and women (2< 0.0001). In particular, the females had a wider spinal canal than males in levels L2, L3 and L4 and a narrower canal in level L5. Spinal width was found to exhibit a decreasing trend in lumbar levels L2 through L5. The evidence for this trend was strong for all three groups: females under the age of 50 (P< 0.0001), men under 50 (2< 0.005), and the older men (P< 0.0001). A similar trend was present for the anteroposterior diameter, as well as for the Transverse diameter. A numerical summary (mean, sd) of all spinal measurements is reported. We believe this study to be an important one that provides useful information regarding the capacity of the lumbar spinal canal, thus helping the surgeon to properly evaluate the stenotic patient

The Magna ROM 21 knee prosthesis was designed in 1994 to match the anatomical characteristics of the Japanese knee and achieve deep knee flexion to suit Japanese lifestyles. The prosthesis has a smaller anteroposterior mediolateral diameter ratio for the femur and tibia than do knees designed in the United States. The purpose of this study was to review the clinical results of the first 159 arthroplasties performed with this prosthesis in order to asses whether this cementless implant had achieved its design objectives. 159 knees were followed for 12.6 to 14.0 years (mean, 13.4 years). Preoperatively the mean The Knee Society knee score and function score were 24.9 and 27.5 points; postoperatively they were 94.6 and 83.8 points. The mean preoperative and postoperative ranges were 106 and 118 degrees, respectively. Total knee arthroplasty with the Magna ROM 21 resulted in an excellent range of motion and a high level of satisfaction wth the operation

Aims

Recurrent dislocation is both a cause and consequence of glenoid bone loss, and the extent of the bony defect is an indicator guiding operative intervention. Literature suggests that loss greater than 25% requires glenoid reconstruction. Measuring bone loss is controversial; studies use different methods to determine this, with no clear evidence of reproducibility. A systematic review was performed to identify existing CT-based methods of quantifying glenoid bone loss and establish their reliability and reproducibility

Aims

In computer simulations, the shape of the range of motion (ROM) of a stem with a cylindrical neck design will be a perfect cone. However, many modern stems have rectangular/oval-shaped necks. We hypothesized that the rectangular/oval stem neck will affect the shape of the ROM and the prosthetic impingement.

Objectives

Cement augmentation of pedicle screws could be used to improve screw stability, especially in osteoporotic vertebrae. However, little is known concerning the influence of different screw types and amount of cement applied. Therefore, the aim of this biomechanical in vitro study was to evaluate the effect of cement augmentation on the screw pull-out force in osteoporotic vertebrae, comparing different pedicle screws (solid and fenestrated) and cement volumes (0 mL, 1 mL or 3 mL).