Kasper Gosvig

Prevalence of malformations of the hip joint and their relationship to sex, groin pain, and risk of osteoarthritis: a population-based survey.

BACKGROUND Although the clinical consequences of femoroacetabular impingement have been well described, little is known about the prevalence of the anatomical malformations associated with this condition in the general population, the natural history of the condition, and the risk estimates for the development of osteoarthritis. METHODS The study material was derived from a cross-sectional population-based radiographic and questionnaire database of 4151 individuals from the Copenhagen Osteoarthritis Substudy cohort between 1991 and 1994. The subjects were primarily white, and all were from the county of Østerbro, Copenhagen, Denmark. The inclusion criteria for this study were met by 1332 men and 2288 women. On the basis of radiographic criteria, the hips were categorized as being without malformations or as having an abnormality consisting of a deep acetabular socket, a pistol grip deformity, or a combination of a deep acetabular socket and a pistol grip deformity. Hip osteoarthritis was defined radiographically as a minimum joint-space width of <or=2 mm. RESULTS The male and female prevalences of hip joint malformations in the 3620 study subjects were 4.3% and 3.6%, respectively, for acetabular dysplasia; 15.2% and 19.4% for a deep acetabular socket; 19.6% and 5.2% for a pistol grip deformity; and 2.9% and 0.9% for a combination of a deep acetabular socket and pistol grip deformity. The male and female prevalences of a normal acetabular roof were 80.5% and 77.0%. We found no significantly increased prevalence of groin pain in subjects whose radiographs showed these hip joint malformations (all p > 0.13). A deep acetabular socket was a significant risk factor for the development of osteoarthritis (risk ratio, 2.4), as was a pistol grip deformity (risk ratio, 2.2). Acetabular dysplasia and the subjects sex were not found to be significant risk factors for the development of hip osteoarthritis (p = 0.053 and p = 0.063, respectively). The prevalence of hip osteoarthritis was 9.5% in men and 11.2% in women. The prevalence of concomitant malformations was 71.0% in men with hip osteoarthritis and 36.6% in women with hip osteoarthritis. CONCLUSIONS In our study population, a deep acetabular socket and a pistol grip deformity were common radiographic findings and were associated with an increased risk of hip osteoarthritis. The high prevalence of osteoarthritis in association with malformations of the hip joint suggests that an increased focus on early identification of malformations should be considered.

The prevalence of cam-type deformity of the hip joint: a survey of 4151 subjects of the copenhagen osteoarthritis study:

Background: Cam deformity is a preosteoarthritic malformation causing premature hip-joint degeneration. While the pathogenetic pathway from deformity to osteoarthrosis (OA) has been well established, almost nothing is known of the malformations epidemiology. Purpose: To determine the distribution of cam deformity in a large, unselected cohort from standardized anteroposterior (AP) pelvic radiographs. Material and Methods: The distribution of cam deformity was assessed in 3202 (1184 male, 2018 female) standardized AP pelvic radiographs using the triangular index (TI) and the α angle. The relationships between cam malformation and self-reported hip pain were evaluated, and the relative importance of known risk factors for cam malformation estimated. Results: We found a pronounced sex-related difference in cam-deformity distribution. The overall prevalence of cam deformity was approximately 17% in men and 4% in women. The distribution of cam deformity was unaltered in subjects with normal joint-space width or other features of hip-joint degeneration. We found no significant association with self-reported hip pain, nor did we find any relative importance of possible risk factors for hip deformity, such as body-mass index (BMI), occupational exposure to heavy workloads, or concomitant acetabular dysplasia. Conclusion:The results lend support to the thesis that cam deformity represents a silent slipped capital epiphysis, predominantly in men, and that it is a far from uncommon deformity in subjects with no apparent evidence of hip-joint osteoarthritis.

Case definitions of knee osteoarthritis in 4,151 unselected subjects: relevance for epidemiological studies: the Copenhagen Osteoarthritis Study.

IntroductionThe aims of the present study were threefold: to examine the distribution of knee joint osteoarthritis in a large, standardized radiological study; to examine the relationships between self reported knee pain and radiological OA; and to examine the natural history of radio-morphological change over age in individuals without radiological features of OA.Materials and MethodsThe Copenhagen Osteoarthritis Study – COS is a substudy of the Copenhagen City Heart Study, a longitudinal regional health survey. From the third inclusion of the CCHS (1992–1994) 4,151 subjects were selected for subsequent standardized radiography of the pelvis, the knees, the hands, the wrists, and the lumbar spine. Images were analyzed and knee joint osteoarthritis (OA) was classified according to the radiographic atlas of Kellgren and Lawrence. Joint space width (JSW) was measured at three sites within both the medial and the lateral compartment.ResultsFor the entire cohort the prevalence of radiological knee joint OA of all grades was 38.7% for men and 44.2% for women. Age stratification documented increasing knee joint OA both in regard to prevalence and morphological severity. Knee pain was universally correlated to the Kellgren and Lawrence severity of OA. In a subgroup with no features of radiological OA, a significant and linear decline in JSW with increasing age was found.ConclusionWe found a clear relationship between self-reported knee pain and radiological osteoarthritis. Pain was proportionally related to the severity of change. We also demonstrated a significant diminishing of joint space width with increasing age in individuals without apparent radiological degeneration.

A new measurement for posterior tilt predicts reoperation in undisplaced femoral neck fractures: 113 consecutive patients treated by internal fixation and followed for 1 year.

Background and purpose Preoperative posterior tilt in undisplaced (Garden I–II) femoral neck fractures is thought to influence rates of reoperation. However, an exact method for its measurement has not yet been presented. We designed a new measurement for posterior tilt on preoperative lateral radiographs and investigated its association with later reoperation. Patients and methods A consecutive series of 113 patients, ≥ 60 years of age with undisplaced (Garden I–II) femoral neck fractures treated with two parallel implants, was assessed regarding patient characteristics, radiographs, and rate of reoperation within the first year. In a subgroup of 50 randomly selected patients, reliability tests for measurement of posterior tilt were performed. Results Intra-and interclass coefficients for the new measurement were ≥ 0.94. 23% (26/113) of patients were reoperated and increased posterior tilt was an accurate predictor of failure (p = 0.002). 14/25 of posteriorly tilted fractures ≥ 20° were reoperated, as compared to 12/88 of fractures with less tilt (p < 0.001). In multiple logistic regression analysis including sex, age, ASA score, cognitive function, new mobility score, time from admission to operation, surgeons expertise, postoperative reduction, and implant positioning, a preoperative posterior tilt of ≥ 20° was the only significant predictor of reoperation (p < 0.001). Interpretation The new measurement for posterior tilt appears to be reliable and able to predict reoperation in patients with undisplaced (Garden I–II) femoral neck fractures.

The prevalence of predisposing deformity in osteoarthritic hip joints

It is becoming increasingly evident that hip joint deformities may be major contributors to the development of osteoarthritis, and the term ‘idiopathic osteoarthritis’ may be inappropriate in many cases. Our study cohort was derived from the Copenhagen Osteoarthritis Sub-study, a cross sectional population-based database of 4151 individuals, all of whom had a standard anteroposterior weight-bearing pelvic radiograph taken. Hip joints were classified according to type and degree of deformity. We defined hip osteoarthritis by a minimum joint space width of ≤ 2mm. This cut-off has a significant relationship in both sexes with the clinical presentation. The study cohort which fulfilled these inclusion criteria consisted of 322 females (149 right hips and 173 left hips) and 162 males (77 right hips and 85 left hips) with osteoarthritis. We found an overall prevalence of predisposing hip deformities in females of 62.4% and in males of 78.9%. Minor and major deformities showed the same prevalence. Both sexes had a comparable prevalence of minor and major hip joint deformity, except for pistol grip deformity, which was more prevalent in men. We concluded that ‘idiopathic osteoarthritis’ is uncommon, and that even minor predisposing deformities are associated with hip osteoarthritis.

Cam deformity and hip degeneration are common after fixation of a slipped capital femoral epiphysis

Background and purpose — Slipped capital femoral epiphysis is thought to result in cam deformity and femoroacetabular impingement. We examined: (1) cam-type deformity, (2) labral degeneration, chondrolabral damage, and osteoarthritic development, and (3) the clinical and patient-reported outcome after fixation of slipped capital femoral epiphysis (SCFE). Methods — We identified 28 patients who were treated with fixation of SCFE from 1991 to 1998. 17 patients with 24 affected hips were willing to participate and were evaluated 10–17 years postoperatively. Median age at surgery was 12 (10–14) years. Clinical examination, WOMAC, SF-36 measuring physical and mental function, a structured interview, radiography, and MRI examination were conducted at follow-up. Results — Median preoperative Southwick angle was 22o (IQR: 12–27). Follow-up radiographs showed cam deformity in 14 of the 24 affected hips and a Tönnis grade > 1 in 1 affected hip. MRI showed pathological alpha angles in 15 affected hips, labral degeneration in 13, and chondrolabral damage in 4. Median SF-36 physical score was 54 (IQR: 49–56) and median mental score was 56 (IQR: 54–58). These scores were comparable to those of a Danish population-based cohort of similar age and sex distribution. Median WOMAC score was 100 (IQR: 84–100). Interpretation — In 17 patients (24 affected hips), we found signs of cam deformity in 18 hips and early stages of joint degeneration in 10 hips. Our observations support the emerging consensus that SCFE is a precursor of cam deformity, FAI, and joint degeneration. Neither clinical examination nor SF-36 or WOMAC scores indicated physical compromise.

The Effect of Botulinum Toxin A Injections in the Spine Muscles for Cerebral Palsy Scoliosis, Examined in a Prospective, Randomized Triple-blinded Study.

Study Design. A prospective, randomized triple-blinded cross-over design treating with either botulinum toxin A (BXT) or saline (NaCl). Objective. To examine the efficacy of BTX treatment in cerebral palsy scoliosis (CPS). Summary of Background Data. Intramuscular injections with BTX have been used off label in treating CPS. 1 prospective study has been conducted, demonstrating in both radiological and clinical improvement, whereas showing no side effects or complications. Methods. Subjects (brace-treated CPS between 2 and 18 yr) were injected using ultrasonic-guidance with either NaCl or BTX in selected spine muscles with 6 mo intervals (block randomization, sealed envelope). Radiographs of the spine and clinical follow-up were captured before and 6 weeks after each injection. Primary outcome parameter was radiological change in Cobb angle, where a 7° change was regarded as an effect (1 SD). Radiological parameters were measured before and 6 weeks after treatment by 3 experienced doctors separately. Moreover, clinical results were evaluated by the pediatric quality of life score and systematic open questioning of the parents about the childs wellbeing. Subjects, researchers, and monitors were blinded during the trial. Appropriate permissions (2008-004584-19) and no funding were obtained. Results. 16 cerebral palsy patients (GFMCS III-V) with CPS were consecutively included, whereas 6 patients were excluded. There were no drop-outs to follow-up, but 1 possible serious adverse event of pneumonia resulting in death was recorded and the study was terminated. No significant radiological or clinical changes were detected when compared with NaCl injections using Wilcoxon matched pair signed-rank test. Conclusion. No positive radiological or clinical effects were demonstrated by this treatment, except for the parents initial subjective but positive appraisal of the effect. However, the study was terminated due to 1 possible severe adverse event and scheduled numbers needed to treat (hence power) were not reached. Level of Evidence: 1

The effects of rotation on radiological parameters in the spine

Background Vertebral rotation in straight spines or in spines with small scoliosis may potentially affect measurement of radiological parameters in both the frontal and sagittal plane. This is important, since it could lead to potential misdiagnosis of scoliosis and other clinical consequences, and until now, this has not been examined. Purpose To examine the effect of axial vertebral rotation of the spine on measurement of common radiological parameters. Material and Methods Reconstructions from computed tomography scans of 40 consecutive included and anonymized patients with straight spines or small scoliosis. Fourteen sagittal and coronal reconstructions covering the whole pelvis and spine were executed. Radiographic parameters in both the frontal and sagittal plane were measured blinded and separately by three doctors. These parameters were evaluated for inter-rater reliability using intraclass correlation coefficient and mixed model analysis for the effects of rotation. The parameters were also analyzed sub-stratified according to “Lenkes classification” and 15 sub-categories of thoracic and lumbar Cobbs angle (CA). Results Vertebral rotation in general does not have any significant effects in both the frontal and sagittal plane. However, there are significant effects on CA and spinopelvic radiologic parameters in extreme rotation or for larger scoliosis. Inter-rater reliability was very good to good. Conclusion In conclusion, axial spinal rotation does not influence common radiological parameters in the frontal and sagittal plane, except in cases of extreme rotation or large scoliosis for selected parameters; thus, this does not lead to potential misinterpretation in scoliosis diagnosis, treatment, or research.