The use of a dual mobility cup in the management of recurrent dislocations of hip hemiarthroplasty

Background

Dislocation is one of the most frequent causes of failure of hemiarthroplasties of the hip, which is the most common treatment for femoral neck fractures in elderly patients. A revision with conversion to total hip arthroplasty is the gold standard in case of failure of closed reduction: however, the use of standard or modular components shows variable outcomes. The use of a dual mobility cup has been evaluated in patients with unstable implants, given the good outcomes obtained in primary and revision surgery. The aim of this study was to assess the results of revisions by dual mobility cups in unstable hemiarthroplasties.

Materials and methods

Thirty-one patients (mean age 75.4 years) were retrospectively evaluated between 2006 and 2010 after conversion to total hip arthroplasty with dual mobility cups for recurrent dislocations. The mean number of dislocations was 2.6 (range 2–5). The evaluation was performed by the American Society of Anesthesiologists physical function score (ASA) and the Harris hip score, and several radiologic criteria.

Results

The mean follow-up was 3.8 years. No recurrence of dislocation was recorded. The ASA score remained unchanged, and the mean Harris hip score improved from 62.2 before dislocation to 76.0 points postoperatively.

Conclusions

Dual mobility cups may be a useful option in the treatment of a hemiarthroplasty dislocation. No risk of a new revision due to instability after insertion of dual mobility cups resulted in our experience, and this option may be strongly considered in cases of revisions of unstable hemiarthroplasties. Level of evidence IV.

     

The use of a dual-mobility concept in total hip arthroplasty patients with spastic disorders

Introduction

Total hip arthroplasty (THA) is one of the treatment options in patients with cerebral palsy (CP) with painful osteoarthritis of the hip. However, the risk of dislocation of the prosthesis is higher in patients with CP when compared with physically normal patients. In this retrospective study of ten consecutive cases, we hypothesized that the use of a dual-mobility cup could reduce this risk of dislocation combined with good functional results.

Materials and methods

From January 2008 until October 2010, eight patients (ten hips) with CP who consecutively received a THA using a dual-mobility cup were identified. At the time of surgery, the average age of the patient group was 54 years (range 43–61). Latest follow-up took place after on average 39 months (range 22–56 months). All patients or their caregivers were interviewed by telephone. They were asked if dislocation of the prosthesis had occurred. To evaluate quality of life and health in general, patients completed the SF-36 questionnaire.

Results

None of the prostheses had dislocated at the latest follow-up. Reoperation was needed in one patient after a periprosthetic fracture. Radiologic evaluation showed a mean cup inclination of 46 (range 27–58). On average, the quality of life of patients in this study was found to be limited in particular on the domains of physical health and functioning, while a fair to good score was measured at the six other different domains.

Conclusion

The use of a dual-mobility cup in THA in patients with CP can lead to favourable results with respect to dislocation and clinical outcome.     

Hip dislocations after 2,734 elective unilateral fast-track total hip arthroplasties: incidence,circumstances and predisposing factors

Study design

Retrospective review of prospectively collected data.

Objective

To investigate the incidence of hip dislocation 90 days after total hip arthroplasty in relation to time after surgery, mechanism of dislocation and predisposing factors.

Methods

Prospective data on preoperative patient characteristics from six Danish arthroplasty departments with similar fast-track approaches were cross-referenced with the Danish National Patient Registry for complete 90-day follow-up on readmissions, including emergency-room contacts. Complete patient files and postoperative radiographs were reviewed in case of dislocations. Unadjusted comparisons were made using t test/Chi-square analyses, while evaluation of risk factors potentially predisposing to dislocations was done using uni- and multivariate regression analysis.

Results

A total of 2,734 consecutive unselected procedures were available for analysis, of which 65 (2.4 %) had dislocations. Of these, eight were during index admission and five were treated and discharged from the emergency room. Mechanisms of dislocation were most often movement while supine or sitting for the first 30 days and due to squatting/bending from day 31 to 90. The 65 patients with dislocations had suboptimal cup placement in 34 (52.3 %), and a femoral head size of <36 mm in 20 (30.8 %) cases. Predisposing factors of dislocation were age ≥75 [OR:1.96 (1.18–3.38)], pharmacologically treated psychiatric disease [OR:2.37 (1.29–4.36)] and department of surgery [OR:2.27 (1.31–3.40)] but not hospital stay of <4 days. Departments with recommendations for activity restrictions had fewer dislocations than a department without restrictions.

Conclusions

Patients ≥75 years and with pharmacologically treated psychiatric disease may be at increased risk of dislocations after fast-track total hip arthroplasty. Further studies including detailed information on patient and prosthesis characteristics, and activity restrictions are needed to reduce the risk of dislocation.     

Porous tantalum shells and augments for acetabular cup revisions

Purpose

The purpose of this study was to evaluate early functional results of revision hip arthroplasty with pelvic bone loss revised with porous tantalum (PT) acetabular components.

Methods

Twenty-five consecutive patients (25 hips) with loose acetabular components after total hip arthroplasty with a minimum of Paprosky IIa pelvic bone loss treated with PT cups with and without modular augments were retrospectively reviewed. Clinical outcomes were assessed using Harris hip score, and Western Ontario and McMaster Universities scores. Mean follow-up was 20.5 months and no patient was lost during follow-up.

Results

The average Harris hip score, and Western Ontario and McMaster Universities scores improved from 40 and 36 preoperatively to 79 and 73 postoperatively, respectively. No statistically significant differences in functional outcome scores were found between the group with moderate (Paprosky IIa, b) and severe (Paprosky IIc or more) acetabular bone loss. At the most recent radiographic evaluation, 24 cups demonstrated no lucent lines and 1 cup had lucent lines but remained well fixed. One cup was revised for traumatic dislocation but was found well fixed at open reduction. There were no septic or aseptic failures in this series.

Conclusion

While awaiting longer-term follow-up studies, trabecular metal components show sufficient primary stability and appear suitable for revision hip arthroplasty with acetabular bone loss.     

Dual mobility acetabular component in revision total hip arthroplasty for persistent dislocation: no dislocations in 50 hips after 1–5 years

Background

A dual mobility cup has the theoretic potential to improve stability in primary total hip arthroplasty (THA) and mid-term cohort results are favorable. We hypothesized that use of a new-generation dual mobility cup in revision arthroplasty prevents dislocation in patients with a history of recurrent dislocation of the THA.

Materials and methods

We performed a retrospective cohort study of patients receiving an isolated acetabular revision with a dual mobility cup for recurrent dislocation of the prosthesis with a minimum follow-up of 1 year. Kaplan–Meier survival analyses were performed with dislocation as a primary endpoint and re-revision for any reason as a secondary endpoint.

Results

Forty-nine consecutive patients (50 hips) were included; none of the patients was lost to follow-up. The median follow-up was 29 months (range 12–66 months). Two patients died from unrelated causes. Survival after 56 months was 100 % based on dislocation and 93 % (95 % CI 79–98 %) based on re-revision for any reason. Radiologic analysis revealed no osteolysis or radiolucent lines around the acetabular component during the follow-up period.

Conclusion

The dual mobility cup is an efficient solution for instability of THA with a favorable implant survival at 56 months.

Level of evidence

Level 4, retrospective case series.     

Cementless dual-mobility cup in total hip arthroplasty revision

Purpose

Dislocation is a frequent complication in total hip arthroplasty (THA) revision. Cup fixation is the second concern. In order to know outcomes at two years, we prospectively followed a continuous series of 78 patients to demonstrate that cementless dual-mobility cup (DMC) used in revision THA is safe as regards dislocation risk and bone fixation.

Method

We enrolled 78 consecutive patients (79 cases) in a prospective study. Mean interval between index surgery and revision was 12.9 years. Mean age at revision was 75.5 years. Two types of cementless DMC were used: a standard DMC in 68 cases with low-grade bone defect (Paprosky grade 1 and 2), and a specific design reconstruction DMC in 11 cases with severe bone loss (Paprosky grade 3).

Results

At two years of follow-up, 68 patients were reviewed; four were lost to follow-up., and six patients were deceased. We identified three types of situations at risk:standard risk (33 cases), Paprosky grade 1 or 2; medium risk (37 cases), revision for recurrent instability (21), periprosthetic fractures (14) or severe loosening Paprosky grade 3 without femorotomy (2); high risk (nine cases), revision for severe loosening with a femorotomy. One (1.3 %) patient dislocated her hip at one month without recurrence. Revision rate for dislocation was 0 %; two (2.7 %) early mechanical failures occurred.

Conclusion

Considering outcomes of this series, cementless DMC can be suggested in THA revision surgery.     

Acetabular cup positioning in revision total hip arthroplasty with Paprosky type III acetabular defects: Martell radiographic analysis

Purpose

This study evaluates acetabular cup position in the setting of revision total hip arthroplasty (THA) with severe acetabular bone defects.

Methods

With a definition of safe zone of abduction (30–50°) and anteversion (5–25°), acetabular cup position was measured by a digital image analysis program for 34 patients with Paprosky type III acetabular bone defects.

Results

There were 24 cups (71 %) for abduction and 26 cups (76 %) for anteversion located in the safe zone. Nineteen cups (56 %) were within the safe zone for both abduction and anteversion. There was no dislocation, however one cup out of the safe zone resulted in early cup failure due to aseptic loosening.

Conclusions

The acetabular cup positioning in patients with Paprosky type III defects was 'optimal' in half of the cases. The prevalence of optimal acetabular cup position was similar to those reported in primary THA, suggesting that the presence of a large acetabular bone defect may not be a significant risk factor for suboptimal acetabular cup positioning in the setting of revision THA.     

Evaluation of clinical outcomes of cementless total hip arthroplasty in patients under 30 years of age

Background

Historically, performing a successful hip joint replacement in patients aged fewer than 30 years has been an orthopedic challenge. The newer generation of prostheses and surgical techniques has the potential to increase the longevity of implants. The purpose of this study was to evaluate the outcomes of cementless hip arthroplasty in patients aged fewer than 30 years.

Materials and methods

In this cross-sectional study, 41 patients (46 hips) were studied with a mean age of 24, 4 (from 17 to 30 years) of whom underwent cementless metal–polyethylene hip arthroplasty from 2004 to 2007. The Harris hip score (HHS) was used to assess the functional consequences. Patients were followed up in terms of early complications (thrombophlebitis of the lower limbs, dislocation, hematoma and infection) and late complications (aseptic loosening, dislocation and reoperation) at weeks 3 and 6, at 3 and 6 months, 1 year after surgery and annually thereafter.

Results

Patients were followed for an average of 5 years and 2 months (from 51 to 82 months). One early complication (symptomatic thrombophlebitis) and one late dislocation (2.2 %) were observed. There were no cases of aseptic loosening or osteolysis at the end of follow-up. The preoperative HHS was 59.6 (from 41 to 76), which rose to 82 and 83.5 after the 1-year and final follow-up, respectively, which was a significant increase.

Conclusions

Hip arthroplasty using a new generation of cementless proximal porous prosthesis with resistant polyethylene to cover the joint surfaces in patients aged fewer than 30 years is satisfactory and is accompanied by low complications.     

The risk of dislocation after total hip arthroplasty for fractures is decreased with retentive cups

Purpose

Total hip arthroplasty (THA) has been efficacious for treating hip fractures in healthy older patients. However, in those patients with fractures a widely variable prevalence of dislocation has been reported, partly because of varying durations of follow up for this specific end-point. The purpose of the present study was to determine the cumulative risk of dislocation in these patients with fractures and to investigate if retentive cups decrease the risk of dislocation.

Methods

Between 2000 and 2005, 325 patients with neck fracture underwent primary THA using a retentive (325 hips) cup. The results of these 325 acetabular cups were compared to 180 THA without retentive cups performed for neck fractures in the same hospital between 1995 and 2000 by the same surgical team. The mean age of the 505 patients was 75 years (range 65–85). All patients were followed for a minimum of five years for radiographic evidence of implant failure. The patients were followed at routine intervals and were specifically queried about dislocation. The cumulative risk of dislocation and recurrent dislocation was calculated with use of the Kaplan–Meier method.

Results

For patients without retentive cups, the cumulative risk of a first-time dislocation was 5 % at one month and 12 % at one year and then rose at a constant rate of approximately 1 % every year to 16 % at five years. For patients with retentive cups, the cumulative risk of a first-time dislocation was 1 % at one month, 2 % at one year and then did not changed at five years. There were no differences in the mortality rates or in loosening rates among the treatment groups. The rate of secondary surgery was highest in the group without retentive (10 % for recurrent dislocation) compared with 1 % in the group treated with retentive cups. In absence of retentive cups, multivariate analysis revealed that the relative risk of dislocation for female patients (as compared with male patients) was 2.1 and that the relative risk for patients who were 80 years old or more (as compared with those who were less than 80 years old) was 1.5. Two underlying diagnoses occurring during follow up—cognitively impaired patients or neurologic disease—were also associated with a significantly greater risk of dislocation in absence of retentive cup. For these patients the risk was also decreased with a retentive cup.

Conclusion

With standard cups the incidence of dislocation is highest in the first year after arthroplasty and then continues at a relatively constant rate for the life of the arthroplasty. Patients at highest risk are old female patients and those with a diagnosis of neurologic disease. Retentive cups in these patients are an effective technique to prevent post-operative hip dislocation.     

Reducing the rate of early primary hip dislocation by combining a change in surgical technique and an increase in femoral head diameter to 36?mm

Introduction

We report how changes to our total hip arthroplasty (THA) surgical practise lead to a decrease in early hip dislocation rates.

Methods

Group B consisted of 421 consecutive primary THA operations performed via a posterior approach. The operative technique included a meticulous repair of the posterior capsule, alignment of the acetabular cup with the transverse acetabular ligament (TAL) and a 36-mm-diameter femoral head. We compared the dislocation rates and cost implications of this technique to a historical control Group A consisting of 389 patients. The control group had their THA performed with no repair of the capsule, no identification of the TAL and all received a 28-mm-diameter head. Our primary outcome is the rate of early hip dislocation and we hypothesised that we can reduce the rate of early hip dislocation with this new regime.

Results

In Group B there were no early dislocations (within 6?months) and two (0.5?%) dislocations within 18?months; minimum follow-up time was 18?months with a range of (18–96?months). This compared to a 1.8?% early dislocation rate and a 2.6?% rate at 18?months in Group A; minimum follow-up time was 60?months with a range of (60–112?months). These results were statistically significant (p?=?0.006).

Conclusion

We suggest that when primary hip arthroplasty is performed through a posterior approach, a low early dislocation rate can be achieved using the described methods.     

Application of temporarily functional antibiotic-containing bone cement prosthesis in revision hip arthroplasty

Purpose

To investigate the clinical outcome of two-stage revision total hip arthroplasty for infected hip arthroplasty using antibiotic-impregnated cement prosthesis.

Materials and methods

Forty-one patients, who suffered from an infection after hip replacement or internal fixation of femoral neck and trochanteric fractures, were treated with a two-stage revision hip arthroplasty and followed up for an average of 37 months. All the patients were implanted with antibiotic-impregnated cement prosthesis as one-stage treatment and were then managed with two-stage revision hip arthroplasty after 12–24 weeks. During the follow-up, Merle d’Aubigné hip score and Harris score were employed for assessment of hip function, and infection recurrence was observed.

Results

According to Merle d’Aubigné hip score, 16 patients (39.2 %) were excellent, 19 (46.3 %) were good, 6 (14.6 %) were moderate, and no bad result and the average score was 15.42. Mean Harris score of preoperation, interval period, and postoperation was 46.7, 66.5, and 92.3, respectively. There was no infection recurrence.

Conclusion

Two-stage revision total hip arthroplasty for infected hip arthroplasty using antibiotic-impregnated cement prosthesis has a satisfying clinical outcome.     

Modular sleeves with ceramic heads in isolated acetabular cup revision in younger patients—laboratory and experimental analysis of suitability and clinical outcomes

Purpose

One possibility in hip arthroplasty revisions is to combine a modular ceramic head with an adapter or sleeve in isolated acetabular cup replacement. This study consisted of an experimental part to analyse the reliability of taper damage predictions, and a clinical part to analyse the outcomes of modular ceramic head implantation in a case series of isolated cup replacements.

Methods

Analysis of scratch size on 11 explanted hip stems were examined macroscopically and by stereomicroscopy to classify damage to the conical taper. The second part consisted of a prospective analysis of isolated cup revisions using a modular ceramic head, performed in two orthopedic centres.

Results

Analysis of scratch size on the taper yielded inter-observer correlations of 0.545–0.909; comparison with stereomicroscopic data recordings yielded a moderate correlation, with values between 0.545 and 0.090. The clinical study included 47 isolated acetabular cup revisions involving modular ceramic heads. Ceramic head failure did not occur during the average clinical and radiological observation period of 26 months. Mean Harris Hip Score (HHS) at follow-up was 70 points.

Conclusion

From these results, it can be concluded that damage to the implanted stem taper cannot be reliably predicted intraoperatively. Nevertheless, the clinical outcomes did show that there were no problems with the ceramic heads over the short observation period. The application of modular ceramic heads in younger patients requiring isolated cup replacement requires proper risk-benefit analysis, but is possible and appears to be a safe procedure.     

Return to work and sports after total hip replacement

Introduction

Expectations of patients requiring total hip replacement have become higher than in the past and are often well beyond pain relief and improved mobility. Return to work and sporting activity are important factors to be considered when advising patients preoperatively. The objective of this study was to analyse the return to sports and work rates in patients still in employment and to analyse potential influencing factors.

Materials and methods

Patients under the age of 65 who had a total hip replacement performed at a university teaching hospital were identified from the local arthroplasty database and contacted. Pre and postoperative levels of sporting activity and work were recorded. We also recorded the time point at which they returned to these activities.

Results

285 total hip replacements were carried out on 239 patients. At the time of follow-up 170 of the patients were working. The mean length of time to return to work was 13.9 weeks (SD 7.7). 78 % returned to work without any restrictions, 18.6 % in heavy manual jobs. The mean time taken to return to sports or similar physical activities was 18.8 weeks (SD 8.8) weeks. Those with a lower body mass index returned to work and sporting activities faster.

Conclusions

Our data show that the majority of patients undergoing total hip replacement can expect to return to work and sporting activities within 4–6 months. Activities at work are often initially limited and physical performance may not fully return to the expected level. Patients with a high body mass index take longer to return to work and sporting activities.     

Revision total hip replacement with a cemented long femoral component: minimum 9-year follow-up results

Background

Surgical revision after failed total hip replacement is a technically challenging procedure. The aim of this study was to analyze the long-term results of revision total hip replacement using a cemented long femoral component and identify factors that influence the results.

Methods

We retrospectively reviewed 34 hips in 33 patients who had undergone revision total hip replacement using a cemented long femoral component between 1994 and 2001. Hip function was evaluated according to the scoring system of the Japanese Orthopaedic Association. Radiographic examination was performed for evaluation of stem loosening, and its possible risk factors were investigated.

Results

The mean follow-up duration was 11.3 years (9–15). Perioperative complications included intraoperative femoral cortex perforation (six hips, 18 %), dislocation (five hips, 15 %), deep venous thrombosis (one hip, 3 %) and postoperative periprosthetic fracture (one hip, 3 %). The mean preoperative Japanese Orthopaedic Association hip score was 50.3 ± 14.9 vs 78.2 ± 11.5 at the latest follow-up. The Kaplan–Meier survival rate at 15 years, calculated using radiological failure or re-revision of the femoral component for any reason as the end point, was 87 or 100 %, respectively. The failure-free survival rate for the subgroup with a good-quality cement mantle was significantly higher than that for the subgroup with poor quality (p = 0.033).

Conclusions

The quality of cementation was identified as a significant risk factor for further loosening. Revision total hip replacement using a cemented long femoral component yielded satisfactory long-term results in this series.     

A critical analysis of radiographic factors in patients who develop dislocation after elective primary total hip arthroplasty

Purpose

In order to diminish total hip arthroplasty (THA) dislocation rate, surgeons strive to achieve adequate component orientation, offset and limb length. In addition, dislocation rate can theoretically be reduced by increasing head diameter and by choosing implants with favorable head-to-neck and cup-to head ratios. We assessed nine radiographic and implant-related parameters associated with an increased risk of dislocation in patients who sustained a dislocation and in those with a stable arthroplasty.

Methods

A total of 1,487 consecutive elective primary THAs performed by a single surgeon, using a posterolateral approach were reviewed at an average follow-up of 18 months (range, 1–112). Fixation was hybrid in 85 % of hips and non-cemented in 15 %. Thirty-eight patients (38 hips, 2.5 %) sustained at least one dislocation. Thirty-seven patients with good quality, standardized anteroposterior radiographs were selected as a “study group”. The study group was matched-paired (1:3) with patients who had a stable arthroplasty based on gender, age, BMI, diagnosis and follow-up. Variables compared between the groups included: head size, cup size, head-to-neck ratio, cup-to-head ratio, leg-length discrepancy, offset, cup inclination, cup version and cup orientation based on the safe zone defined by Lewinnek et al.

Results

None of the nine parameters showed a statistically significant difference between the groups.

Discussion

In this study, 90 % of patients who developed a dislocation had properly positioned acetabular components. In addition, the vast majority of patients in the study group had adequate restoration of limb length and offset. The results of our study may be useful for the orthopedic surgeons who discuss instability following THA surgery, particularly in patients with radiographically sound reconstructions.

     

Medial placement of the acetabular component in an alumina-on-alumina total hip arthroplasty: a comparative study with propensity score matching

Purpose

In an alumina-on-alumina total hip arthroplasty (THA), recommended with a small inclination angle <45°, the acetabular component (cup) may be positioned more medially to be covered almost completely by host bone. The purpose of this study was to identify the correlating factors and to evaluate the outcomes of medial placement of the cup in patients with alumina-on-alumina THAs.

Methods

Using the propensity score matching with age, gender, body mass index, initial diagnosis, and the length of follow-up as variables, 38 hips with a medialized cup and 38 hips with a non-medialized one were identified from 389 hips in 347 who patients underwent primary alumina-on-alumina THA and followed up for more than 7 years. Clinical and radiological outcomes were compared between the two groups.

Results

Preoperative acetabular medial wall thickness and the cup inclination angle were significantly smaller in the medialization group compared to the non-medialization group. Center edge angle, cup size, and coverage by host bone were not significantly different between the two groups. The hip center of rotation was significantly medialized in the medialization group. The Harris hip scores were not significantly different between the two groups. No component loosening or osteolysis was observed and no revision was required in either groups.

Conclusions

Thin acetabular medial wall and a small inclination angle of the cup were the correlating factors of medial placement of the cup in patients who underwent an alumina-on-alumina THA. Medial placement did not lead to differences in the clinical or radiological outcomes.     

Modified posterior soft tissue repair for the prevention of early postoperative dislocation in total hip arthroplasty

Purpose

Dislocation following total hip arthroplasty (THA) with the posterior approach has been quite a common and bothering complication. Previous researches suggest that careful repair of the posterior structures significantly reduces this risk. The purposes of the present study were to describe a modified posterior soft tissue repair procedure in THA using a suture anchor (TwinFix Ti 5.0, Smith & Nephew, Andover, MA) and evaluate the early postoperative dislocation rate.

Methods

From July 2004 to June 2008, 220 consecutive primary total hip arthroplasties were performed using the modified surgical approach. The average age in the group was 46.4 years (range from 21 to 90) at the time of the procedure. The rate of postoperative hip dislocation, as well as any signs of complications related to the technique, has been observed and analyzed in this study.

Results

There was no postoperative dislocation following primary THA in 220 cases, and no signs of complications related to the technique, such as greater trochanteric fractures and sciatic nerve palsy, have been noted in any of the cases at their most recent follow-up.

Conclusions

These initial results demonstrate that the modified repair in THA using the suture anchor can serve as an effective and reliable mean for prevention of early postoperative dislocation     

The necessity of pharmacological prophylaxis against venous thromboembolism in major joint arthroplasty

Purpose

Venous thromboembolism (VTE) is a recognised post-operative complication of major lower limb joint arthroplasty. Current National Institute for Health and Clinical Excellence (NICE) guidelines suggest the use of both mechanical and pharmacological prophylaxis following hip and knee replacement. Since the introduction of enhanced recovery programmes following hip and knee arthroplasty the requirement for routine pharmacological VTE prophylaxis has been questioned. The purpose of this study was to assess the efficacy of pharmacological prophylaxis against symptomatic VTE in patients undergoing hip and knee arthroplasty under an enhanced recovery programme.

Methods

Symptomatic VTE incidence was audited in 1,100 patients undergoing primary or revision total hip or knee arthroplasty at the same hospital with only mechanical prophylaxis from 2007 to 2009. Following addition of chemical prophylaxis (enoxaparin) symptomatic VTE incidence in 522 patients undergoing primary or revision total hip or knee arthroplasty from 2011 to 2012 was re-audited.

Results

In the mechanical prophylaxis group incidence of DVT was 0.73 % [95 % confidence interval (CI) 0.37–1.43 %] and incidence of pulmonary embolism (PE) 0.91 % (95 % CI 0.49–1.67 %). Following addition of pharmacological prophylaxis incidence of DVT was 0.57 % (95 % CI 0.20–1.68 %) and incidence of PE 1.15 % (95 % CI 0.53–2.48 %).

Conclusions

We found no statistically significant difference in symptomatic VTE incidence following the addition of enoxaparin. We question whether routine pharmacological prophylaxis still has a role following total hip and knee arthroplasty. Peri-operative optimisation, including post-operative analgesia and mobility, with current enhanced recovery programmes may be sufficient. As anticoagulants carry increased risk of post-operative bleeding and wound ooze, in addition to significant cost implications, their role remains controversial.     

Osteosynthese und Pfannenwechsel bei periprothetischer Azetabulumfraktur über einen Kocher-Langenbeck-Zugang

Objective

Reconstruction/stable fixation of the acetabular columns to create an adequate periacetabular requirement for the implantation of a revision cup.

Indications

Displaced/nondisplaced fractures with involvement of the posterior column. Resulting instability of the cup in an adequate bone stock situation.

Contraindications

Periprosthetic acetabulum fractures with inadequate bone stock. Extended periacetabular defects with loss of anchorage options. Isolated periprosthetic fractures of the anterior column. Septic loosening.

Surgical technique

Dorsal approach. Dislocation of hip. Mechanical testing of inlaying acetabular cup. With unstable cup situation explantation of the cup, fracture fixation of acetabulum with dorsal double plate osteosynthesis along the posterior column. Cup revision. Hip joint reposition.

Postoperative management

Early mobilization; partial weight bearing for 12 weeks. Thrombosis prophylaxis. Clinical and radiological follow-ups.

Results

Periprosthetic acetabular fracture in 17 patients with 9 fractures after primary total hip replacement (THR), 8 after revision THR. Fractures: 12 due to trauma, 5 spontaneously; 7 anterior column fractures, 5 transverse fractures, 4 posterior column fractures, 1 two column fracture after hemiendoprosthesis. 5 type 1 fractures and 12 type 2 fractures. Operatively treated cases (10/17) received 3 reinforcement ring, 2 pedestal cup, 1 standard revision cup, cup-1 cage construct, 1 ventral plate osteosynthesis, 1 dorsal plate osteosynthesis, and 1 dorsal plate osteosynthesis plus cup revision (10-month Harris Hip Score 78 points). Radiological follow-up for 10 patients: consolidation of fractures without dislocation and a fixed acetabular cup. No revision surgeries during follow-up; 2 hip dislocations, 1 transient sciatic nerve palsy.