Cross-cultural adaptation and validation of the Slovenian version of the Core outcome measures index for low back pain.

BACKGROUND: To conduct a cross-cultural adaptation and validation of the Core Outcome Measures Index (COMI) in the Slovenian language, for use in patients with low back pain. METHODS: The English version of COMI was translated into Slovene following established guidelines. Three hundred fifty-three patients with chronic low back pain were recruited from the Orthopedic clinic department of a tertiary care teaching institution. Data quality, construct validity, responsiveness, and test-retest reliability of the COMI were assessed. RESULTS: The questionnaire was generally well accepted with no missing values. The majority of items exhibited only mild ceiling effects (below 20.0%) and somewhat more prominent floor effects, which were similar to previous studies (4.5-78.8%). Correlations with Oswestry Disability Index (ODI) were high (ρ = 0.76 between overall COMI and ODI scores), suggesting that the Slovene version of COMI had high construct validity. Additionally, the Slovene version of COMI successfully captured surgical patients' improvement in their low back problem after surgery (overall COMI score change: Z = - 9.34, p < .001, r = - 0.53) and showed acceptable test-retest reliability (ICC = 0.86). CONCLUSIONS: The Slovene version of COMI showed good psychometric properties, comparable to those of previously tested language versions. It represents a valuable instrument for the use in future domestic and multicenter clinical studies.

Polyetheretherketone (PEEK) cages for anterior column reconstruction in pyogenic vertebral osteomyelitis.

The objective of study was to evaluate a case series of patients in whom polyetheretherketone (PEEK) cages were used for anterior column reconstruction in vertebral osteomyelitis. Fifteen patients underwent clinical and radiological evaluation with average follow-up of 26 months. Parameters assessed were time of surgery, blood loss, segmental kyphosis or lordosis angle, time to solid bony fusion, ambulatory status, and functional outcome. Mean time of surgery was 150 min with mean blood loss of 530 ml. One patient died in early postoperative period. All patients without preoperative neurologic deficit were walking unaided first day postoperatively. Solid bony fusion was demonstrated in 14 patients, on average 7.1 months postoperatively. Functional outcome at the latest follow-up was excellent, good, or fair in 86%. Two failures with recurrent infection were treated with PEEK cage removal and reinstrumentation. High success rate could be expected when PEEK cages are used for anterior column support in pyogenic vertebral osteomyelitis.

Failure to maintain segmental lordosis during TLIF for one-level degenerative spondylolisthesis negatively affects clinical outcome 5 years postoperatively: a prospective cohort of 57 patients.

PURPOSE: The present study aimed to determine whether obtaining adequate lumbar (LL) or segmental (SL) lordosis during instrumented TLIF for one-level degenerative spondylolisthesis affects midterm clinical outcome. METHODS: The study was designed as a prospective one, including 57 patients who underwent single-level TLIF surgery for degenerative spondylolisthesis. Patients were analyzed globally with additional subgroup analysis according to pelvic incidence (PI). Radiographic analysis of spinopelvic sagittal parameters was conducted pre- and postoperatively. Clinical examination including ODI score was performed preoperatively, 1 and 5 years postoperatively. RESULTS: Significant improvement in ODI scores at 1 and 5 years postoperatively (p < 0.001) was demonstrated. There was a significant correlation between anterior shift of SVA and failure to improve SL (p = 0.046). Moreover, anterior SVA shift correlated with increased values of ODI score both 1 and 5 years postoperatively. In low-PI group, failure to correct LL correlated with high ODI scores 5 years postoperatively (r = - 0.499, p = 0.005). CONCLUSIONS: Failure to correct segmental lordosis during surgery for one-level degenerative spondylolisthesis resulted in anterior displacement of the center of gravity, which in turn correlated with unfavorable clinical outcome 1 and 5 years postoperatively. In patients with low PI, failure to maintain lumbar lordosis correlated with unfavorable clinical outcome 5 years after surgery. LEVEL OF EVIDENCE: II. These slides can be retrieved under Electronic Supplementary Material.

Early initiation of a strength training based rehabilitation after lumbar spine fusion improves core muscle strength: a randomized controlled trial.

BACKGROUND: To analyze the safety and effects of early initiation of rehabilitation including objective measurement outcomes after lumbar spine fusion based on principles of strength training. METHODS: The study recruited 27 patients, aged 45 to 70 years, who had undergone lumbar spine fusion. The method of concealed random allocation without blocking was used to form two groups. The strength training group started rehabilitation 3 weeks after surgery. Patients exercised twice weekly over 9 weeks focusing on muscle activation of lumbopelvic stabilization muscles. The control group followed a standard postoperative protocol, where no exercises were performed at that stage of rehabilitation. Functional outcomes and plain radiographs were evaluated at 3 weeks and subsequently at 3 and 18 months after the surgery. RESULTS: No hardware loosening of failure was observed in the training group. Both groups improved their walking speed after 3 months (p < 0.01), although improvement in the training group was significantly greater than in the control group (p < 0.01). Moreover, the training group significantly improved after the training period in all isometric trunk muscles measurements (p < 0.03), standing reach height (p < 0.02), and pre-activation pattern (p < 0.05). After 18 months, no training effects were observed. CONCLUSIONS: The study showed that early initiation of a postoperative rehabilitation program based on principles of strength training is safe, 3 weeks after lumbar spine fusion, and enable earlier functional recovery than standard rehabilitation protocol. TRIAL REGISTRATION: The study is registered at the US National Institutes of Health ( ClinicalTrials.gov ) NCT03349580 . The date of registration: November 21, 2017 - Retrospectively registered.

Vertebral End-Plate Perforation for Intervertebral Disc Height Preservation After Single-level Lumbar Discectomy: A Randomized-controlled Trial.

STUDY DESIGN: Pilot single-centre, stratified, prospective, randomized, double-blinded, parallel-group, controlled study. OBJECTIVE: To determine whether vertebral end-plate perforation after lumbar discectomy causes annulus reparation and intervertebral disc volume restoration. To determine that after 6 months there would be no clinical differences between the control and study group. SUMMARY OF BACKGROUND DATA: Low back pain is the most common long-term complication after lumbar discectomy. It is mainly caused by intervertebral disc space loss, which promotes progressive degeneration. This is the first study to test the efficiency of a previously described method (vertebral end-plate perforation) that should advocate for annulus fibrosus reparation and disc space restoration. METHODS: We selected 30 eligible patients according to inclusion and exclusion criteria and randomly assigned them to the control (no end-plate perforation) or study (end-plate perforation) group. Each patient was evaluated in 5 different periods, where data were collected [preoperative and 6-mo follow-up magnetic resonance imaging and functional outcome data: visual analogue scale (VAS) back, VAS legs, Oswestry disability index (ODI)]. Intervertebral space volume (ISV) and height (ISH) were measured form the magnetic resonance images. Statistical analysis was performed using paired t test and linear regression. P<0.05 was considered statistically significant. RESULTS: We found no statistically significant difference between the control group and the study group concerning ISV (P=0.6808) and ISH (P=0.8981) 6 months after surgery. No statistically significant differences were found between ODI, VAS back, and VAS legs after 6 months between the 2 groups, however, there were statistically significant differences between these parameters in different time periods. Correlation between the volume of disc tissue removed and preoperative versus postoperative difference in ISV was statistically significant (P=0.0020). CONCLUSIONS: The present study showed positive correlation between the volume of removed disc tissue and decrease in postoperative ISV and ISH. There were no statistically significant differences in ISV and ISH between the group with end-plate perforation and the control group 6 months after lumbar discectomy. Clinical outcome and disability were significantly improved in both groups 3 and 6 months after surgery.

The Oswestry Disability Index, confirmatory factor analysis in a sample of 35,263 verifies a one-factor structure but practicality issues remain.

PURPOSE: To analyze the factor structure of the Oswestry Disability Index (ODI) in a large symptomatic low back pain (LBP) population using exploratory (EFA) and confirmatory factor analysis (CFA). METHODS: Analysis of pooled baseline ODI LBP patient data from the international Spine Tango registry of EUROSPINE, the Spine Society of Europe. The sample, with n = 35,263 (55.2% female; age 15-99, median 59 years), included 76.1% of patients with a degenerative disease, and 23.9% of the patients with various other spinal conditions. The initial EFA provided a hypothetical construct for consideration. Subsequent CFA was considered in three scenarios: the full sample and separate genders. Models were compared empirically for best fit. RESULTS: The EFA indicated a one-factor solution accounting for 54% of the total variance. The CFA analysis based on the full sample confirmed this one-factor structure. Sub-group analyses by gender achieved good model fit for configural and partial metric invariance, but not scalar invariance. A possible two-construct model solution as outlined by previous researchers: dynamic-activities (personal care, lifting, walking, sex and social) and static-activities (pain, sleep, standing, travelling and sitting) was not preferred. CONCLUSIONS: The ODI demonstrated a one-factor structure in a large LBP sample. A potential two-factor model was considered, but not found appropriate for constructs of dynamic and static activity. The use of the single summary score for the ODI is psychometrically supported. However, practicality limitations were reported for use in the clinical and research settings. Researchers are encouraged to consider a shift towards newer, more sensitive and robustly developed instruments.

Comparative Analysis of Combined (First Anterior, Then Posterior) Versus Only Posterior Approach for Treating Severe Scoliosis: A Mean Follow Up of 8.5 Years.

STUDY DESIGN: A retrospective, one center, institutional review board approved study. OBJECTIVE: Two methods of operative treatments were compared in order to evaluate whether a two-stage approach is justified for correction of bigger idiopathic scoliosis curves. Two stage surgery, combined anterior approach in first operation and posterior instrumentation and correction in the second operation. One stage surgery included only posterior instrumentation and correction. SUMMARY OF BACKGROUND DATA: Studies comparing two-stage approach and only posterior approach are rather scarce, with shorter follow up and lack of clinical data. METHODS: Three hundred forty eight patients with idiopathic scoliosis were operated using Cotrel-Dubousset (CD) hybrid instrumentation with pedicle screw and hooks. Only patients with curvatures more than or equal to 61° were analyzed and divided in two groups: two stage surgery (N = 30) and one stage surgery (N = 46). The radiographic parameters as well as duration of operation, hospitalization time, and number of segments included in fusion and clinical outcome were analyzed. RESULTS: No statistically significant difference was observed in correction between two-stage group (average correction 69%) and only posterior approach group (average correction 66%). However, there were statistically significant differences regarding hospitalization time, duration of the surgery, and the number of instrumented segments. CONCLUSION: Two-stage surgery has only a limited advantage in terms of postoperative correction angle compared with the posterior approach. Posterior instrumentation and correction is satisfactory, especially taking into account that the patient is subjected to only one surgery. LEVEL OF EVIDENCE: 3.

Long-term Results of Surgical Treatment for Symptomatic Anterior Cervical Osteophytes: A Case Series With Review of the Literature.

PURPOSE: Presentation of a case series (10 patients) with surgical treatment of symptomatic anterior cervical osteophytes, a review of the latest literature and discussion of surgical methods. OBJECTIVE: To present our results of the surgical treatment and compare them with the existing literature. On the basis of the gathered data, we aim to propose an optimal choice of surgical treatment. SUMMARY OF BACKGROUND DATA: Anterior cervical osteophytes rarely cause symptoms that require surgical treatment, which disables bigger cohort analysis. Surgery always includes anterior osteophyte resection. Some authors propose instrumented anterior fusion after osteophyte resection as the first choice of surgery in order to prevent regrowth of osteophytes, whereas others support resection without fusion because of beneficial long-term results. METHODS: Diagnostics included plain radiography, contrast esophagography, computed tomography and/or magnetic resonance imaging. Treatment consisted of left lateral cervicotomy and osteophytectomy. We performed a systematic review of the literature from 2006. RESULTS: Average age at surgery was 69.5 years (63-77 y), average follow-up 61.9 months (15-117 mo). Twenty-five osteophytes were resected, with average size of 12.7 mm (4-22 mm) preoperatively and 5.12 mm (0-12 mm) at final follow-up. Average functional outcome swallowing scale score before surgery was 3.3 (2-5) and 1.2 (0-5) at final follow-up. Only 1 patient had reoccurrence of symptoms because of osseous etiology. CONCLUSIONS: Symptomatic ventral cervical osteophytes can be successfully treated by surgery. In the majority of patients, osteophytes do not regrow significantly in the long term, precluding the need for prophylactic instrumented fusion after osteophyte resection.

Operative stabilization of the remaining mobile segment in ankylosed cervical spine in systemic onset - juvenile idiopathic arthritis: A case report.

We describe a case of a 19-year-old young man with oligoarthritis type of juvenile idiopathic arthritis, who presented with several month duration of lower neck pain and progressive muscular weakness of all four limbs. X-rays of the cervical spine demonstrated spontaneous apophyseal joint fusion from the occipital condyle to C6 and from C7 to Th2 with marked instability between C6 and C7. Surgical intervention began with anterolateral approach to the cervical spine performing decompression, insertion of cage and anterior vertebral plate and screws, followed by posterior approach and fixation. Care was taken to restore sagittal balance. The condition was successfully operatively managed with multisegmental, both column fixation and fusion, resulting in pain cessation and resolution of myelopathy. Postoperatively, minor swallowing difficulties were noted, which ceased after three days. Patient was able to move around in a wheelchair on the sixth postoperative day. Stiff neck collar was advised for three months postoperatively with neck pain slowly decreasing in the course of first postoperative month. On the follow-up visit six months after the surgery patient exhibited no signs of spastic tetraparesis, X-rays of the cervical spine revealed solid bony fusion at single mobile segment C6-C7. He was able to gaze horizontally while sitting in a wheelchair. Signs of myelopathy with stiff neck and single movable segment raised concerns about intubation, but were successfully managed using awake fiber-optic intubation. Avoidance of tracheostomy enabled us to perform an anterolateral approach without increasing the risk of wound infection. Regarding surgical procedure, the same principles are obeyed as in management of fracture in ankylosing spondylitis or Mb. Forestrier.

Minimum cement volume for vertebroplasty.

PURPOSE: Percutaneous vertebroplasty is a widely used vertebral augmentation technique. It is a minimally invasive and low-risk procedure, but has some disadvantages with a relatively high number of bone cement leaks and adjacent vertebral fractures. The aim of this cadaveric study was to determine the minimum percentage of cement fill volume in vertebroplasty needed to restore vertebral stiffness and adjacent intradiscal pressure. METHODS: Thirteen thoracolumbar spine mobile segments were loaded to induce a vertebral fracture. After fracture vertebroplasty was performed, four times in the same fractured vertebra. The injected cement volume was 5 % of the fractured vertebral volume to reach 5, 10, 15 and 20 % of cement fill. Biomechanical testing was performed before the fracture, after the fracture and after each cement injection. RESULTS: After vertebral fracture compressive stiffness was reduced to 47 % of the pre-fracture value and was partially restored to 61 % after 10 % cement fill. With vertebroplasty intradiscal pressure gradually increased, depending on specimen position, from 48 to a total of 71 % at 15 % of cement fill. CONCLUSIONS: Compressive stiffness and intradiscal pressure increase with the percentage of cement fill. Fifteen per cent of cement fill was the limit beyond which no substantial increase in compressive stiffness or intradiscal pressure could be detected and is the minimum volume of cement we recommend for vertebroplasty. In the average thoracolumbar vertebra this means 4-6 ml of cement.

Unfavorable hip stress distribution after Legg-Calvé-Perthes syndrome: a 25-year follow-up of 135 hips.

To study the effect of hip and pelvis geometry on development of the hip after Perthes disease, we determined the resultant hip force and contact hip stress distribution in a population of 135 adult hips of patients who had been treated for Perthes disease in childhood. Contra-lateral hips with no record of disease were taken as the control population. Biomechanical parameters were determined by mathematical models for resultant hip force in one-legged stance and for contact hip stress, which use as an input the geometrical parameters assessed from anteroposterior radiographs. The mathematical model for stress was upgraded to account for the deviation of the femoral head shape from spherical. No differences were found in resultant hip force and in peak contact hip stress between the hips that were in childhood subject to Perthes disease and the control population, but a considerable (148%) and significant (p < 0.001) difference was found in the contact hip stress gradient index, expressing an unfavorable, steep decrease of contact stress at the lateral acetabular rim. This finding indicates an increased risk of early coxarthritis in hips subject to Perthes disease.

Influencing segmental balance in isthmic spondylolisthesis using transforaminal lumbar interbody fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The objective of the study was to analyze segmental balance in patients with isthmic spondylolisthesis undergoing single-level transforaminal lumbar interbody fusion (TLIF). SUMMARY OF BACKGROUND DATA: Sagittal malalignment of the fused segment was suggested to be associated with degeneration of the adjacent segment. Meticulous surgical technique and particular attention to hardware positioning with the aim to restore segmental balance at the fusion level have been recommended to achieve better long-term clinical outcomes, but no single study addressed all proposed factors. METHODS: Standard lateral radiographs of the lumbosacral spine in the neutral standing position were retrospectively obtained for 32 patients undergoing single-level TLIF. Preoperative versus postoperative versus final follow-up (12 to 60 mo) values of translational slip (TS), posterior disc space height (PDSH), and segmental lordosis (SL) were compared using paired samples t test. Change in SL postoperatively between groups of next grouping variables: type and position of the interbody device, and rod contouring, was compared using 2-tailed independent samples t test. Association between position of the interbody device and immediate PDSH was addressed with regression analysis postoperatively and at final follow-up. RESULTS: Mean TS decreased (P<0.001) and mean PDSH increased (P=0.002), but no significant change in SL occurred postoperatively (P=0.811). Increase in SL was observed with ventral positioning of the interbody device (P=0.009) and with bending of connecting rods (P=0.023). During follow-up, there was increase in TS (P=0.002) and decrease in PDSH (P<0.001) and SL (P<0.001) compared with postoperative values. Lower PDSH was found to be associated with more ventral positioning of the interbody device, both postoperatively (P=0.035) and at final follow-up (P=0.029). CONCLUSIONS: This study demonstrates that reduction of TS and restoration of disc space height are readily achieved with single-level TLIF. However, to establish an increase in SL consistent rod contouring and meticulous anterior placement of the interbody device should be applied. Excessive ventral positioning of the cages might result in insufficient disc space height restoration.

Analysis of four manual and a computerized method for measuring axial vertebral rotation in computed tomography images.

STUDY DESIGN: Axial vertebral rotation (AVR) of normal and scoliotic vertebrae was measured in computed tomography (CT) images by three observers using different manual and a computerized method. OBJECTIVE: To analyze 4 manual and a computerized method for measuring AVR in CT images. SUMMARY OF BACKGROUND DATA: Manual measurement of AVR is difficult and error-prone when compared with computerized methods. To the best of our knowledge, a systematic comparison of the established manual with a computerized method has not been performed yet. METHODS: AVRs of 14 normal and 14 scoliotic vertebrae from CT images were measured (a) manually using the methods of Aaro and Dahlborn, Spine 1981;6:460-7, Ho et al, Spine 1993;18:1173-7, Krismer et al, J Spinal Disord 1999;12:126-30, and Göçen et al, J Spinal Disord 1998;11:210-4., and (b) automatically using a computerized method, which is based on the evaluation of vertebral symmetry in 2 dimensions (2D) and in 3 dimensions (3D). RESULTS.: The computerized method was most consistent with the method of Aaro and Dahlborn, which also proved to be the most reproducible and reliable manual method. The low overall intraobserver variability (1.1 degrees SD) and interobserver variability (1.8 degrees SD) of the computerized method indicate that the symmetry-based determination of AVR is reproducible and reliable, as the localization of vertebral centroids is the major source of its variability. CONCLUSION: The computerized method yielded higher reproducibility and reliability of AVR measurements, indicating that it may represent a feasible alternative to manual methods, moreover because it is also faster and more operator-friendly.

Two different causes of acute respiratory failure in a patient with diffuse idiopathic skeletal hyperostosis and ankylosed cervical spine.

We report a case of 73-year-old man with massive hyperostosis of the cervical spine associated with diffuse idiopathic skeletal hyperostosis (DISH), resulting in dysphagia, hoarseness and acute respiratory insufficiency. An emergency operation was performed, which involved excision of osteophytes at the level of C6-C7, compressing the trachea against enlarged sternoclavicular joints, also affected by DISH. Approximately 3 years later, the patient sustained a whiplash injury in a low impact car accident, resulting in a C3-C4 fracture dislocation, which was not immediately diagnosed because he did not seek medical attention after the accident. For the next 6 months, he had constant cervical pain, which was growing worse and eventually became associated with dysphagia and dyspnoea, ending once again in acute respiratory failure due to bilateral palsy of the vocal cords. The patient underwent a second operation, which comprised partial reduction and combined anteroposterior fixation of the fractured vertebrae. Twenty months after the second operation, mild hoarseness was still present, but all other symptoms had disappeared. The clinical manifestations, diagnosis and treatment of the two unusual complications of DISH are discussed.

Cumulative hip contact stress predicts osteoarthritis in DDH.

UNLABELLED: Hip stresses are generally believed to influence whether a hip develops osteoarthritis (OA); similarly, various osteotomies have been proposed to reduce contact stresses and the risk of OA. We asked whether elevated hip contact stress predicted osteoarthritis in initially asymptomatic human hips. We identified 58 nonoperatively treated nonsubluxated hips with developmental dysplasia (DDH) without symptoms at skeletal maturity; the control group included 48 adult hips without hip disease. The minimum followup was 20 years (mean, 29 years; range, 20-41 years). Peak contact stress was computed with the HIPSTRESS method using anteroposterior pelvic radiographs at skeletal maturity. The cumulative contact stress was determined by multiplying the peak contact stress by age at followup. We compared WOMAC scores and radiographic indices of OA. Dysplastic hips had higher mean peak contact and higher mean cumulative contact stress than normal hips. Mean WOMAC scores and percentage of asymptomatic hips in the study group (mean age 51 years) were similar to those in the control group (mean age 68 years). After adjusting for gender and age, the cumulative contact stress, Wiberg center-edge angle, body mass index, but not the peak contact stress, independently predicted the final WOMAC score in dysplastic hips but not in normal hips. Cumulative contact stress predicted early hip OA better than the Wiberg center-edge angle. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Methyl-methacrylate bone cement surface does not promote platelet aggregation or plasma coagulation in vitro.

Leakage of viscous bone cement into venous blood possibly resulting in pulmonary embolism may occur during percutaneous vertebroplasty. Our aim was to study if bone cement surface or cement liquid component could induce platelet aggregation or plasma coagulation in vitro. Two types of commonly used methyl-methacrylate bone cement, Palacos (Heraeus Kulzer, Germany) and Vertebroplastic (DePuy, Acro Med, England), were smeared on thin glass slides that were inserted over the bottom of cuvettes immediately or after 24 h, and platelet aggregation was recorded over 10 min. Bone cement liquid component, containing methyl-methacrylate monomer and N,N-dimethyl-p-toluidine, was tested in 2% and 4% final concentration. Partial thromboplastin time (PTT) was determined by the hook method in the presence of bone cement-smeared glass slides or 6% bone cement liquid. Both types of bone cement, either fresh or aged, did not promote platelet aggregation, whereas collagen-coated glass slides induced substantial platelet aggregation (65 +/- 37%). On the other hand, bone cement liquids reduced platelet aggregation induced by collagen solution to an average of less than 15% (p < 0.01). Bone cement, fresh or aged, had no effect on PTT, but bone cement liquids significantly prolonged PTT: median and 1st-3rd interquartile range 149 (96-171) s for Vertebroplastic and 132 (99-194) s for Palacos, p = 0.03 for both comparisons with normal pool plasma without additives that had PTT of 69 (62-71) s. We conclude that the surface of fresh or aged bone cement is not thrombogenic in vitro. The bone cement liquid inhibits platelet aggregation and plasma clotting in relatively high concentrations that cannot be expected in vivo.

Gradient of contact stress in normal and dysplastic human hips.

The stress gradient index (G(p)) is introduced for the assessment of dysplasia in human hip joint. The absolute value of G(p) is equal to the magnitude of the gradient of the contact stress at the lateral acetabular rim. The parameter G(p) normalized with respect to the body weight (W(B)) is determined from the standard anteroposterior radiographs of adult human hips and pelvises using the mathematical model. The average value of G(p)/W(B) was determined for the group of dysplastic hips and for the group of normal hips. In the group of normal hips the average value of G(p)/W(B) is smaller (-0.445x10(5) m(-3)) than in the group of dysplastic hips (+1.481x10(5) m(-3)). The difference is statistically significant P<0.001. The average value of G(p)/W(B) changes its sign at the value of the centre-edge angle theta(CE) approximately 20( composite function ) which is usually considered as the boundary value of theta(CE) (lower limit) for the normal hips. Accordingly we suggest a new definition for the hip dysplasia with respect to the size and sign of the normalized stress gradient index G(p)/W(B). The hips with positive G(p)/W(B) are considered to be dysplastic while the hips with negative G(p)/W(B) are considered to be normal. The statistically significant correlation between the value of the Harris hip score, used in the clinical assessment of the hip dysplasia, and the normalized stress gradient index was found.

The effect of proprioceptive training in patients with recurrent dislocation of the patella.

Eleven patients with recurrent dislocation of the patella were subjected to knee proprioceptive training. Patients exhibited a gain in their Lysholm and Activity scores (p 0.03 and 0.009). No patient needed operative procedure.

The effect of proprioceptive training on neuromuscular function in patients with patellar pain.

Eight patients with patellar pain underwent knee proprioceptive training. The maximal knee extension torque associated with the Vastus Lateralis EMG signal increased (p 0.001 and 0.039). Although muscle balance was not improved, all the patients improved their clinical scores.

Biochemical aspects of Salter's osteotomy for treatment of acetabular dysplasia.

The center-edge (CE) angle was measured on serial antero-posterior radiographs of 44 hips treated by Salter's innominate osteotomy for developmental dysplasia of the hip. Radiographic examination according to Severin was performed and the peak hip joint pressure was calculated using geometrical parameters determined from radiographs at the most recent follow-up examination, 7 to 13 years postoperatively.At the latest follow-up assessment, there was a positive correlation between the postoperative CE angle and radiographic results. Negative correlation was found between the postoperative CE angle and peak hip joint pressure at the latest follow up.In conclusion, Salter's osteotomy performed to treat developmental dysplasia of the hip should involve radical acetabular correction resulting in maximum increase of the CE angle.