Background and Aim: SF-36 has been used frequently as a measurement tool to evaluate the effect of total hip arthroplasty (THA) operation on the patient’s quality of life (QoL). There is though a lack of data describing how QoL is affected if the patients have medical co-morbidities before the operation or if they suffer postoperative complications after THA. With this study we wanted to describe the effect on QoL of pre-operative co-morbidity and post-operative surgical and thromboembolic complications after THA.

Material and methods: This study was part of the ESMOS study where 500 consecutive THA patients (both primary and revision THA) were followed prospectively for one year, with the purpose to collect all surgical and thromboembolic events that these patients experienced. The patients were asked to fill in a SF-36 form the day before the operation and one year after the operation. 397 (79.4%) of the patients had two forms sufficient for further data analysis in this study. Co-morbidity data was measured before the operation. Complications were measured with structured interviews by two study persons the fifth postoperative day and at telephone interviews after 3 and 12 month. All reported events were verified according to predefined criteria in the patient’s medical journal.

Results: The majority of the THA patients experienced a gain in their quality of life one year after THA. One year after THA the co-morbid patients had a significantly lower QoL score in all scales, but they still gained from the operation. Patients that experienced either a surgical or a thromboembolic complication had lower SF-36 score one year post-operatively compared to patients without complications. Subgroup analysis revealed that the small group of patients with deep infection, aseptic loosening or re-operation because of malfunction of the prosthesis had a fall in QoL compared to the pre-operative value and scored significantly worse than all other patient groups.

Conclusion: THA is a successful operation when QoL is measured one year postoperatively. Pre-operative co-morbidity and postoperative surgical or thrombo-embolic complications does give a smaller gain in QoL compared to patients without co-morbidity and patients without complications. The small but important group of patients with deep infection, aseptic loosening and malfunction re-operation, were the only to loose QoL one year after THA in this study.

Background: Results after Total Hip Replacement (THR) including prosthetic design, surgical complications and prosthetic survival are frequently reported – however, information on the rate of complications in general is sparse.

Aim and Methods: The aim was to collect information on all complications after THR within the first year after surgery. This study consisted of 500 consecutive patients (386 with primary THR operated due to degenerative osteoarthritis (OA) and 112 with primary THR due to secondary OA or revision THR). These patients were followed by structured interviews at surgery and 3 and 12 months after discharge. Surgical and cardiovascular complications were registered. No interventions related to this study were done. The patients followed the standard care of departments.

Results: 500 patients were included; two withdrew their consent, leaving 498 for the follow up one year after surgery or until death. Of the 498 patients 103 (20.6%) experienced at least one complication related to the operation within the one year observation period. Among the 386 primary THR with degenerative OA the complicationrate was 17.9%.

Of the 498 patients 6.6% experienced one or more symptomatic cardiovascular complications (deep vein thrombosis, pulmonary embolism (PE), myocardial infarction, and stroke, transient ischemic attack or retinal vein thrombosis). In the degenerative OA group 4.7% (95% Cl: 2.6–6.8%) had a cardiovascular event and in the secondary OA + revision group the rate was 13.4% (95% Cl: 10.2–16.6). The rate of complications directly related to the surgery (dislocation, perioperative fracture, bleeding, aseptic loosening, deep infection, peroneal palsy or superficial wound infection) was 15.4% (95% Cl: 12.3–18.6). In the degenerative OA and secondary OA/revision group the rates were: 14.2% and 19.6% respectively. Nine (1.8%) patients died, five of cardiovascular reasons (disseminated intravascular coagulation, PE followed by renal failure, PE followed by cerebral ischemia and stroke), the first three in close relation to the operation.

Discussion: A complication-rate of 20.6% as found in the present study seems to be very high. There is no reason to think that these numbers are not correct. To our knowledge, only one other study has been published with data about complications in general (Williams O., J Arthroplasty17:165–171, 2002). Their results are based on a mix of hospital file data, patient and general practitioner questionnaires with varying response rates – and their findings, although a bit lower in number, support the data from this study. The present study indicates, that there is a need for continuous registration of these common complications– even in the group of primary THR due to degenerative osteoarthritis, usually thought of as being the least complicated. The complication rate must be included in the information given to patients offered THR.

Introduction: Cam-type femoroacetabular impingement (FAI) is a pre-osteoarthritic condition causing premature joint degeneration. Cam-deformities are characterised by decreased cranial offset of the femoral head/neck junction and aspherity of the femoral head causing delamination of the acetabular cartilage and detachment of the acetabular labrum. To asses the epidemiological aspects of cam-type FAI we evaluated Nötzlis alpha angle and our own Triangular Index (TI) for use on plain AP pelvic radiographs.

Materials and Methods: Cam malformation was assessed in 2.803 pelvic radiographs by the alpha (α) angle and the TI to define pathological cut off values. The α-angle and TI were assessed in AP and lateral hip radiographs of 164 patients scheduled for THR and the influence of varying rotation on the α-angle and TI was assessed in femoral specimens. The distribution of Cam-deformities was assessed in 3.712 standardized AP pelvic radiographs using the α-angle and TI.

Results: Mean AP α-angle male/female was 55°/45°. The α-angle and TI was highly interrelated, OR 8.6–35 (p< 0.001). Almost all cam-malformations were identifiable in AP projections, sensitivity 88–94% compared to axial view. The TI proved robust for cam identification during rotation (± 20°) compared to the α-angle (−10° to +20°). The distribution of pathologic TI and α-angle (Right/Left) were 11.6/12.5% and 6.1/7.4% in males and 2.2/3.2% and 2.1/3.8% in females. We found a pronounced sexrelated difference in cam-deformity distribution, OR 2.0–6.3 (p< 0.001).

Conclusion: The triangular index and the α-angle were found reliable for epidemiological purpose. Overall prevalence of definite cam-deformity was app. 10% in men and 2,5% in women.

Background: Data on thromboembolic complications (TEC) following major orthopaedic surgery are generally obtained retrospectively from registries or prospectively from large industry-sponsored international multicentre trials. However, the results may differ from those observed in unselected patients in routine operations performed by orthopaedic surgeons. The purpose of the ESMOS study was to describe the number and time of onset of serious symptomatic arterial and venous TEC within 90 days after surgery in an unselected population of patients undergoing total hip replacement (THR).

Patients and methods: A total of 500 (430 primary THR and 70 revision THR) consecutive patients were included in the study performed between January 2004 and May 2005 in Frederiksborg County (Denmark). They were to be followed for 90 days after surgery. Patients were interviewed before surgery for medical history and on days 5 (while in hospital) and 90 (by telephone call) for signs and symptoms of acute myocardial infarction (AMI), pulmonary embolism (PE), deep-vein thrombosis (DVT), transitory cerebral ischemia (TCI)/stroke and retinal vein thrombosis (RVT). The validity of the events was confirmed using files from hospital, general practitioner and international criteria.

Results: Overall, 498 patients were followed-up for 90 days, 2 patients having withdrawn consent. In-hospital pharmacological thromboprophylaxis was performed in 499 patients. Twenty-four patients (4.8%) experienced at least one serious TEC up to day 90: 2 (0.4%) patients died from surgical-related complications (no autopsy was performed); 1 (0.2%) patient experienced AMI, 5 (1.0%) had PE, 10 (2.0%) DVT, 4 (0.8%) TCI, and 2 (0.4%) RVT. Moreover, 2 patients experienced two TEC: AMI followed by TCI in a first patient, PE and TCI in a second patient. The first event occurred up to day 5 in 9 patients (38%) and after day 5 in 15 patients (62%). Five patients (1%) had clinically relevant bleeding complications: 3 patients had a single, minor, upper gastrointestinal bleeding episode while in hospital, one patient developed a huge expanding haematoma at the operation site treated with hip spica and another patient a peritoneal haematoma leading to re-operation.

Conclusion: This study performed in an unselected population clearly shows that THR still results in serious TEC in spite of a wide use of modern anaesthesia techniques, thrombosis prophylaxis and early mobilisation. In the future, we need to better identify at-risk patients in order to optimise their management, in particular post-discharge care, and reduce the risk of serious TEC.

Introduction: Re-operations after intertrochanteric fractures (ITF) are often caused by fracture displacement following postoperative mobilisation. The biomechanical complexity of the fracture, implant position, and the patient’s characteristics are known to influence postoperative outcome significantly. We investigated the importance of an intact lateral femoral wall (LFW) for the postoperative displacement after fixation by a sliding compression hip screw (SHS).

Methods: Two hundred and fourteen consecutive patients with ITF fixated by 135° SHS mounted on four hole lateral plates were included between 2002 and 2004. The fractures were preoperatively classified according to the AO/OTA classification system. The status of the greater and lesser trochanter, the integrity of the LFW and implant positioning were assessed postoperatively. Re-operations due to technical failure were recorded for six months.

Results: Only three percent of patients (5/168) with postoperatively intact LFW’s were re-operated within six months, while twenty-two percent (10/46) of patients with fractured LFW’s had been re-operated (p < 0.001). In multivariate logistic regression analyses combining demographic and biomechanical parameters, a compromised LFW was a significant predictor for reoperation (p = 0.010). Seventy-four percent (34/46) of the LFW fractures occurred during the operative procedure itself. Peri-operative LFW fractures only occurred in three percent (3/103) of the AO/OTA type 31A1–A2.1 ITF fractures, compared to thirty-one percent (31/99) of the AO/OTA type 31A2.2–A2.3 fractures (p < 0.001).

Conclusions: A postoperative fractured LFW was found to be the main predictor for reoperation after ITF. Consequently we conclude that patients with pre- or potential postoperative LFW fractures are not treated adequately by SHS. ITF should therefore be classified according to the integrity of the LFW, especially in regard to randomized trials comparing fracture implants.

Background: The epidemiology of Schmorl nodes is based on post-mortem investigations. The proposed pathogenesis of the focal nodes is a bulging of the disc into the vertebral body depending of the degree of osteoporosis. Secondar peripheral osteophytes are formed at the annular insertion.

Study design: A cross sectional epidemiological study of 4151 participants of the Copenhagen Osteoarthritis Study in 1993 with a 13 years follow with the Roland-Morris (R-MQ) back pain questionnaire.

In 1993 standardized, lateral radiographs of the lumbar spine were recorded and the bone mineral density (BMD) was estimated by digital x-ray radiogrammetry of standardised hand x-rays.

Methods: Statistical correlations were made between Schmorl nodes and low back pain in 1993, the R-MQ score, BMD and the presence of osteophytes, disc degeneration and endplate sclerosis.

Results: There were 2610 women and 1538 men. At follow up 1190 women and 674 responded. In 196 cases one or more Schmorl nodes in the lumbar spine were found (women 3.7 %, men 6.5 %). A decreasing prevalence of Schmorl nodes by ages was found in both genders (p< 0.000). At the time of the radiographic examination participants with Schmorl nodes clamed of low back pain (p=0.003). The presence of nodes was without relation to osteophytosis, intervertebral disc degeneration or sclerosis of endplates (p> 0.14) in 1993. Neither was the R-MQ score at follow-up related to Schmorls nodes(p> 0.26). The presence of nodes was associated with higher BMD (mean 0.50 (SD 0.079) versus 0.53 (SD 0.081)(p=0.000), however the difference disappeared taking into account age at examination.

Conclusion: This large scaled epidemiological study cannot confirm the hitherto hold opinion of the implication of the Schmorls nodes. The nodes are not associated with radiological degeneration and osteoporosis neither are they a predictor of lower back pain later in life.

Background/Objective: Since estrogen receptors (ERα/ERβ) were identified in human chondrocytes, animal-and experimental studies have demonstrated the importance of continued estrogen production for the integrity of articular cartilage. However, human epidemiological support of the hypothesis has been inconclusive. The present study investigated the relationship between reduced bone mineral densities (BMD), as a surrogate parameter of endogenous estrogen status – assessed by digital x-ray radiogrammetry (DXR), and reduced minimum hip joint space width (JSW).

Methods: Standardised hand radiographs of the Copenhagen Osteoarthritis Study cohort of 3.913 adults (1.470M/2.443F) with a mean age of 60 years (range, 18–92), were analysed by the X-Posure^™ digital software v. 2.0 (Sectra-Pronosco). The system is operator independent. From 1.200 individual measurements per radiograph mean BMD was calculated. Minimum hip joint JSW was assessed in standardized, pelvic radiographs.

Results: DXR-BMD decreased in both men and women after the age of 45 years, progressively more so in women. While minimum hip JSW in men remained relatively unaltered throughout life, a marked decline in female minimum hip JSW after 45 years was observed. We found moderate, but highly significant relationships between reduced BMD and reduced hip JSW in women (p < 0.001), adjusted for age and dysplastic joint incongruity.

Conclusion: We believe that the present study supports the hypothetical relationship between reduced estrogen levels and hip joint space width reduction in women.

Introduction: The aetiology of scoliosis is not known. Many different mechanisms have been suggested as playing a part in the development. Dysfunction of the segmental paravertebral muscles have been suggested to have some impact on the condition. It is known that the injection of botulinum toxin type B will paralyse muscles by blocking of the motor endplate. The effect has been shown to last up to three months. The experiment was designed to study if segmental muscles in the thoracic region of the spine in pigs play a role in the development of the spine.

Materials and Methods: Six seven days old piglets were used in the experiment. In the lower thoracic region in three levels on the left side the paraspinal muscles were infiltrated with botulinum toxin type B. It was used 10 units of Botox® on each level, a total of 30 units were used on each animal. It was taken care to infiltrate the different small muscles as the toxin does not spread readily to adjacent muscles. The pigs were then left for normal care and development. They all were assessed at four weeks intervals until they were sacrificed three months after initial injection. x-ray were then taken of the spine.

Results: During the follow-up there were no visible changes in the alignment of the spine. The piglets developed normally. On x-ray there were no signs of developmental disturbances and we did not see any signs of scoliotic development. If anything, there was the development of a long curvature in the thoracic spine. On examination there was clear atrophy of the segmental muscles in the injected regions.

Discussion: This experiment suggests that the development of the spine is not guided by either the presence or absence of muscle activation. The dose of Botox® applied to these small muscles should be more than adequate to stop nearly all muscle activity. The pig has a rapid growth period from seven days to three months. Any changes caused by muscle activation should have been detected in this period. It could be that the effect on fast growing animals is shorter than three months. Nevertheless we still saw muscle atrophy at time of sacrifice.

Femoroacetabular cam impingement is thought to be a cause of premature osteoarthritis of the hip.

The presence of cam malformation was determined in 2803 standardised anteroposterior (AP) pelvic radiographs from the Copenhagen Osteoarthritis Study by measuring the alpha (α) angle and the triangular index, a new measure of asphericity of the femoral head. In addition, the α-angle and the triangular index were assessed on the AP and lateral hip radiographs of 82 men and 82 women randomly selected from patients scheduled for total hip replacement (THR). The influence of varying femoral rotation on the α angle and the triangular index was also determined in femoral specimens under experimental conditions.

From the 2803 radiographs the mean AP α-angle was 55° (30° to 100°) in men and 45° (34° to 108°) in women. Approximately 6% of men and 2% of women had cam malformation. The α-angle and triangular index were highly inter-related. Of those patients scheduled for THR, 36 men (44%) and 28 women (35%) had cam malformation identifiable on the AP radiographs. The triangular index proved to be more reliable in detecting cam malformation when the hip was held in varying degrees of rotation.

The combination of the α-angle and the triangular index will allow examination of historical radiographs for epidemiological purposes in following the natural history of the cam deformity.

In a longitudinal case-control study, we followed 81 subjects with dysplasia of the hip and 136 control subjects without dysplasia for ten years assessing radiological evidence of degeneration of the hip at admission and follow-up. There were no cases of subluxation in the group with dysplasia. Neither subjects with dysplasia nor controls had radiological signs of ongoing degenerative disease at admission. The primary radiological discriminator of degeneration of the hip was a change in the minimum joint space width over time. There were no significant differences between these with dysplasia and controls in regard to age, body mass index or occupational exposure to daily repeated lifting at admission.

We found no significant differences in the reduction of the joint space width at follow-up between subjects with dysplasia and the control subjects nor in self-reported pain in the hip. The association of subluxation and/or associated acetabular labral tears with dysplasia of the hip may be a conditional factor for the development of premature osteoarthritis in mildly to moderately dysplastic hips.

We report the results of a prospective longitudinal study of 147 athletes who had had a meniscectomy for an isolated meniscus injury. The patients were reviewed in detail after median periods of 4.5 years and 14.5 years and the results analysed. The frequency of complaints related to the operation increased from 53% at 4.5 years to 67% at 14.5 years, while demonstrable knee instability increased from 10% to 36%. The incidence of radiographic changes of degeneration rose from 40% to 89% and at late review 8% of patients had definite osteoarthritis by the criteria of Ahlback (1968). In consequence 46% had given up or reduced their sporting activity, and 6.5% had changed their occupation. Radiographic deterioration started after the 4.5-year review in 49% of the patients and was more frequent after lateral than medial meniscectomy.