Aims

This study describes and compares the operative management and outcomes in a consecutive case series of patients with dislocated hemiarthroplasties of the hip, and compares outcomes with those of patients not sustaining a dislocation.

Background. Several risk factors for the development of osteonecrosis following treatment of developmental dislocated hip have been reported. The need for further research with a large-enough sample size including statistical adjustment of confounders was demanded. The purpose of the present study was to find reliable predictors of osteonecrosis in patients managed for developmental dislocation of the hip. Methods. A retrospective cohort study of children, who have been hospitalized at our department between January 1998 and February 2007 with a developmental dislocation of the hip, was completed. Sixty-four patients satisfied the criteria for inclusion. Three groups according to age and treatment were identified. Group A and B included patients treated with closed or open reductions aged less than twelve months. Patients of group C were past walking age at the time of reduction and were treated by open reduction combined with concomitant pelvic and femoral osteotomies. The average duration of follow-up for all patients was 6.8 years. Logistic regression analysis was conducted to identify predictors for the development of osteonecrosis. Results. The overall rate of osteonecrosis in group A and B was 27.4% compared to 88.2% in patients of group C. After pooling of all data, no protective effect of the ossific nucleus of the femoral head on the development of osteonecrosis was found (p = 0.14). Additionally, an increase of surgical procedures in children of group C could not be demonstrated (p = 0.17). By using logistic regression analysis the type of reduction and secondary reconstructive procedure due to residual acetabular dysplasia could be identified as predictors for the development of osteonecrosis. Conclusions. Open reduction combined with concomitant osteotomies and secondary reconstructive interventions due to residual acetabular dysplasia increase the risk for osteonecrosis in the treatment of the developmental dislocated hip. Therefore, we advocate early reduction of the dislocated hip in the first year of life to avoid the need for concomitant osteotomies combined with open reduction. Level of Evidence. Prognostic study, level II-1 (retrospective study)

BACKGROUND & AIM. Most previous studies found that the rate of dislocation following primary THA was 2 to 3 % on average. It is expected that minimally invasive (MI) THA has fewer dislocations after surgery because it causes less muscle damage. To ascertain the risk factors of dislocation, we conducted a retrospective study of the occurrence of dislocation after MI-THA in Japanese patients. METHODS. From June 2003 when we began MI-THA to August 2010 primary MI-THAs were performed on 2,042 hips; 1,997 hips with mini-posterior approach (a mean incision of 7 cm) with the repair of posterior soft tissues and 45 hips with other approaches. The dislocation after MI-THA was studied with respect to age, sex, body mass index, the use of navigation system, femoral head size, cup size and approaches. The period of follow-up was from six weeks to seven years. RESULTS. The numbers of dislocation after MI-THA were 13 hips (0.6%). The numbers of posterior and anterior dislocation after MI-THA were nine and four hips, respectively. In the patients undergoing MI-THA, there was a significant difference between non-dislocated hips and dislocated hips, with respect to the average age (57 years vs. 66 years, p<0.017), the numbers of male patients (181 cases (9%) vs. 4 cases (31%), p<0.024), cup size (50 mm vs. 53 mm, p<0.007) and the numbers of cases which used navigation system (1,932 hips (95%) vs. 10 hips (77%), p<0.023). Whereas there was no significant difference between non-dislocated hips and dislocated hips with respect to the body mass index, femoral head size and approaches. DISCUSSION. Several risk factors of the dislocation after primary THA have been reported. In this study we found that MI-THA had fewer risk of dislocation as compared with historic controls. It is suggested that less soft tissue damage can decrease the risk of the dislocation after surgery. The incidence of dislocation was fewer in the younger and female patients undergoing MI-THA with the navigation system than in the older and male patients undergoing MI-THA without the navigation system. The posterior approach combined with the repair of posterior soft tissues did not increase the risk of dislocation after surgery as compared with other approaches. The position of implants is important to prevent dislocation after surgery, and the navigation system can help to obtain a good position of implants. CONCLUSIONS. We conclude that MI-THA can decrease the risk of dislocation after primary THA. Furthermore the combination of MI-THA and the navigation system is very useful to reduce the incidence of dislocation because the use of the navigation system during surgery can be helpful to acquire the precise position of implants

Aims

The aim of this study was to assess the association of mortality and reoperation when comparing cemented and uncemented hemiarthroplasty (HA) in hip fracture patients aged over 65 years.

The purpose of the study is to evaluate the retrospective results of 92 surgically treated spastic hips. Twenty-one patients were able to walk in the community with aids, 19 were able to walk about the house, and 13 were wheelchair bound. The mean age at the time of the operation was 7 yrs (3–18) and the average follow-up was 5. The cohort of the study included 45 tetraplegic patients, 6 diplegic, and 2 hemiplegic. The dislocated hips were 25 and the subluxated ones 67. The surgical treatment included soft tissue and bone procedures. The 53 patients were divided into two age groups: those less than 7yrs old and those older than 7yrs. The cohort was also divided into 39 patients operated in one setting, and 14 operated in more than one. Clinical evaluation was based on the joint range of motion, the ambulatory status and the pain. The radiological evaluation criteria were based on Reimer's migration index, the center-edge angle, Sharp's angle, and neck-femoral angle. We used the interclass correlation coefficient to measure our interobserver reliability for MI 0,93, for CE angle 0,95 and for Sharp's angle 0,81, as the interobserver difference for MI averaged 9% for CE angle 7and for Sharp's angle 3. Statistical analysis of continuous variables was done by Student's t-test or the Wilcoxon rank sum test. Categorical variables were evaluated by Fisher's test. Concerning the walking ability, from the 13 severe quadriplegic patients, none improved his functional level but they achieved better sitting balance. The walking ability of the rest of the patients improved one level in 78% of the cases. The mean preoperative abduction was improved from 24,7 to 33,5, the mean flexion was slightly reduced from 123 preoperatively to 114 postoperatively and the mean extension reduced from −20 preoperatively to −8 postoperatively. Reimer's index reduced from 67,2 to 21,7 postoperatively, the CE angle increased from −10,6 to 20,5, the Sharp's angle increased from 36,9 to 40,5 and the neck-shaft angle increased from 119,7 to 157,5post-operatively. Of greater significance were MI and CE at p<0.05. A migration index of >50% at final follow-up was associated with a worse migration index and a worse CE angle at 1 year post-operatively. 46 hips were evaluated as good, 30 as satisfactory, and 16 as poor. The severe tetraplegic with small-negative CE angle and Reimer's migration index > 50%, as well as the small age of the patients (<7 yrs) were negative prognostic factors. Better results were observed when patients were operated at age <7yrs by soft tissue procedures and MI<30%, while patients >7yrs had satisfactory results only after combined bony and soft tissue procedures and MI <50%. A migration index of >50% at final follow-up was associated with a worse migration index and a worse CE angle at 1 year postoperatively

Aims

The aims of this study were to determine the cumulative ten-year survivorship of hips treated for acetabular fractures using surgical hip dislocation and to identify factors predictive of an unfavourable outcome.

Our study was designed to compare the effect of indometacin with that of a placebo in reducing the incidence of heterotopic ossification in a prospective, randomised trial. A total of 121 patients with displaced fractures of the acetabulum treated by operation through a Kocher-Langenbeck approach was randomised to receive either indometacin (75 mg) sustained release, or a placebo once daily for six weeks. The extent of heterotopic ossification was evaluated on plain radiographs three months after operation. Significant ossification of Brooker grade III to IV occurred in nine of 59 patients (15.2%) in the indometacin group and 12 of 62 (19.4%) receiving the placebo.

We were unable to demonstrate a statistically significant reduction in the incidence of severe heterotopic ossification with the use of indometacin when compared with a placebo (p = 0.722). Based on these results we cannot recommend the routine use of indometacin for prophylaxis against heterotopic ossification after isolated fractures of the acetabulum.

Our aim was to evaluate the efficacy of a two-level reconstruction technique using subchondral miniscrews for the stabilisation of comminuted posterior-wall marginal acetabular fragments before applying lag screws and a buttress plate to the main overlying posterior fragment. Between 1995 and 2003, 29 consecutive patients with acute comminuted displaced posterior-wall fractures of the acetabulum were treated operatively using this technique.

The quality of reduction measured from three standard plain radiographs was graded as anatomical in all 29 hips. The clinical outcome at a mean follow-up of 35 months (24 to 90) was considered to be excellent in five patients (17%), very good in 16 (55%), good in six (21%) and poor in two (7%). The use of the two-level reconstruction technique appears to provide stable fixation and is associated with favourable results in terms of the incidence of post-traumatic osteoarthritis and the clinical outcome. However, poor results may occur in patients over the age of 55 years.

Our aim in this pilot study was to evaluate the fixation of, the bone remodelling around, and the clinical outcome after surgery of a new, uncemented, fully hydroxyapatite-coated, collared and tapered femoral component, designed specifically for elderly patients with a fracture of the femoral neck.

We enrolled 50 patients, of at least 70 years of age, with an acute displaced fracture of the femoral neck in this prospective single-series study. They received a total hip replacement using the new component and were followed up regularly for two years.

Fixation was evaluated by radiostereometric analysis and bone remodelling by dual-energy x-ray absorptiometry. Hip function and the health-related quality of life were assessed using the Harris hip score and the EuroQol-5D.

Up to six weeks post-operatively there was a mean subsidence of 0.2 mm (−2.1 to +0.5) and a retroversion of a mean of 1.2° (−8.2° to +1.5°). No component migrated after three months. The patients had a continuous loss of peri-prosthetic bone which amounted to a mean of 16% (−49% to +10%) at two years. The mean Harris hip score was 82 (51 to 100) after two years.

The two-year results from this pilot study indicate that this new, uncemented femoral component can be used for elderly patients with osteoporotic fractures of the femoral neck.

We aimed to identify variables associated with clinical and radiological outcome following fractures of the acetabulum associated with posterior dislocation of the hip. Using a prospective database of 1076 such fractures, we identified 109 patients with this combined injury managed operatively within three weeks and followed up for two or more years. The patients had a mean age of 42 years (15 to 79), 78 (72%) were male, and 84 (77%) had been involved in motor vehicle accidents. Using multivariate analysis the quality of reduction of the fracture was identified as the only significant predictor of radiological grade, clinical function and the development of post-traumatic arthritis (p < 0.001). All patients lacking anatomical reduction developed arthritis whereas only 25.5% (24 patients) with an anatomical reduction did so (p = 0.05).

The quality of the reduction of the fracture is the most important variable in forecasting the outcome for patients with this injury. The interval to reduction of the dislocation of the hip may be less important than previously described.