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.     

Is etoricoxib effective in preventing heterotopic ossification after primary total hip arthroplasty?

Purpose

Heterotopic ossification is a common complication after total hip arthroplasty. Non-steroidal anti-inflammatory drugs (NSAIDs) are known to prevent heterotopic ossifications effectively, however gastrointestinal complaints are reported frequently. In this study, we investigated whether etoricoxib, a selective cyclo-oxygenase-2 (COX-2) inhibitor that produces fewer gastrointestinal side effects, is an effective alternative for the prevention of heterotopic ossification.

Methods

We investigated the effectiveness of oral etoricoxib 90 mg for seven days in a prospective two-stage study design for phase-2 clinical trials in a small sample of patients (n = 42). A cemented primary total hip arthroplasty was implanted for osteoarthritis. Six months after surgery, heterotopic ossification was determined on anteroposterior pelvic radiographs using the Brooker classification.

Results

No heterotopic ossification was found in 62 % of the patients that took etoricoxib; 31 % of the patients had Brooker grade 1 and 7 % Brooker grade 2 ossification.

Conclusions

Etoricoxib seems effective in preventing heterotopic ossification after total hip arthroplasty. This finding further supports the use of COX-2 inhibitors for the prevention of heterotopic ossification following total hip arthroplasty.     

Ten year results of the collum femoris preserving total hip replacement: a prospective cohort study of seventy five patients

Purpose

The collum femoris preserving (CFP) uncemented prosthesis has a bone-preserving, high subcapital neck resection and a short anatomical stem. The ideal arthroplasty option in the younger, active patient is a subject of some debate. We evaluated midterm outcomes of the CFP in this patient population.

Methods

A prospective, consecutive cohort of 75 CFP total hip replacement (THR) patients with a mean age of 52 years was followed for a mean of 9.3 years. Patients were assessed using the Harris Hip Score (HHS). Pain was assessed using a visual analogue scale (VAS) and activity levels using the University of California, Los Angeles (UCLA) score. Radiographs were evaluated for evidence of loosening. Survivorship was calculated with an endpoint of revision for aseptic loosening or radiographic evidence of loosening.

Results

Mean HHS improved from a mean of 50 pre-operatively to 91 (p < 0.001) postoperatively. Mean pain score was 1, mean patient satisfaction was 9 and mean UCLA score was 6. Two acetabular components were revised for aseptic loosening; no stem required revision. Radiographically, no cases had evidence of loosening. Survivorship was 96.8 % for the acetabular component and 100 % for the stem at ten years. Three patients died from unrelated causes, and five were lost to follow-up.

Conclusions

Bone-preserving hip replacement has increased in popularity as hip replacement in younger and more active individuals increases. The CFP prosthesis has excellent midterm clinical function and survival and provides high levels of satisfaction in young patients.     

Does total hip arthroplasty restore native hip anatomy? Three-dimensional reconstruction analysis

Purpose

Component orientations and positions in total hip arthroplasty (THA) are important parameters in restoring hip function. However, measurements using plain radiographs and 2D computed tomography (CT) slices are affected by patient position during imaging. This study used 3D CT to determine whether contemporary THA restores native hip geometry.

Methods

Fourteen patients with unilateral THA underwent CT scan for 3D hip reconstruction. Hip models of the nonoperated side were mirrored with the implanted side to quantify the differences in hip geometry between sides.

Results

The study demonstrated that combined hip anteversion (sum of acetabular and femoral anteversion) and vertical hip offset significantly increased by 25.3° ± 29.3° (range, −25.7° to 55.9°, p = 0.003) and 4.1 ± 4.7 mm (range, −7.1 to 9.8 mm, p = 0.009) in THAs.

Conclusions

These data suggest that hip anatomy is not fully restored following THA compared with the contralateral native hip.     

Incidence and management of hip dislocation in tumour patients with a modular prosthesis of the proximal femur

Purpose

Little data is available about the incidence and especially the management of hip dislocation following the implantation of modular tumor prostheses of the proximal femur. In this retrospective single-centre study we assessed the incidence of hip dislocation following implantation of a proximal femoral modular prosthesis as well as the success of the subsequent surgical or non-surgical treatment in tumor patients.

Methods

Between 1982 and 2008, 166 tumor patients received a modular prosthesis of the proximal femur at our institution. The average age at the time of surgery was 50 ± 20 years (range, six to 84 years). An additional pelvic reconstruction was done in 14 patients. An artificial band for soft tissue reconstruction of the hip was used in 19 patients. The average time of follow-up was 46 ± 64 months (range, one to 277 months).

Results

The overall dislocation rate after proximal femoral replacement was 13 % after a mean time of seven ± eight months (range, 0.3–33 months) after surgery. Between 1982 and 1986 the dislocation rate was 33 % and declined to 9 % in subsequent years (1987–2008). Patients who had received an additional pelvic reconstruction had a three fold higher dislocation rate (p <0.05). Patients with closed reduction had a 58 % (eight of 12) re-dislocation rate compared to 11 % (one of nine) for open reduction (p = 0.0357).

Conclusions

Dislocation of a modular prosthesis of the proximal femur is a common complication, especially in cases with additional pelvic resection with extensive bone and soft-tissue defects. Open surgical management may be more effective in preventing re-dislocation than closed reduction and bracing alone.     

Total hip arthroplasty versus hemiarthroplasty for displaced femoral neck fractures in the healthy elderly: a meta-analysis and systematic review of randomized trials

Purpose

Displaced femoral neck fractures in healthy elderly patients have traditionally been managed with hemiarthroplasty (HA). Recent data suggest that total hip arthroplasty (THA) may be a better alternative.

Methods

A systematic review of the English literature was conducted. Randomized controlled trials comparing all forms of THA with HA were included. Three authors independently extracted articles and predefined data. Results were pooled using a random effects model.

Results

Eight trials totalling 986 patients were retrieved. After THA 4 % underwent revision surgery versus 7 % after HA. The one-year mortality was equal in both groups: 13 % (THA) versus 15 % (HA). Dislocation rates were 9 % after THA versus 3 % after HA. Equal rates were found for major (25 % in THA versus 24 % in HA) and minor complications (13 % THA versus 14 % HA). The weighted mean of the Harris hip score was 81 points after THA versus 77 after HA. The subdomain pain of the HHS (weighted mean score after THA was 42 versus 39 points for HA), the rate of patients reporting mild to no pain (75 % after THA versus 56 % after HA) and the score of WOMAC (94 points for THA versus 78 for HA) all favored THA. Quality of life measured with the EQ-5D favored THA (0.69 versus 0.57).

Conclusions

Total hip arthroplasty for displaced femoral neck fractures in the fit elderly may lead to higher patient-based outcomes but has higher dislocation rates compared with hemiarthroplasty. Further high-quality randomized clinical trails are needed to provide robust evidence and to definitively answer this clinical question.     

Total hip arthroplasty with acetabular reconstruction using a bulk autograft for patients with developmental dysplasia of the hip results in high loosening rates at mid-term follow-up

Purpose

Managing a deficient acetabulum in patients with developmental dysplasia of the hip (DDH) can be challenging. The purpose of the study was to determine the mid-term results of total hip arthroplasty (THA) using a bulk structural autograft for reconstruction of the acetabular roof in patients with DDH.

Methods

Between 1982 and 1999, 112 patients underwent THA with acetabular roof-plasty using a bulk structural autograft for secondary osteoarthritis related to DDH. A total of 106 patients (115 hips) met inclusion criteria and were followed for an average of 11.6 years (seven to 24 years). The mean age was 52.5 years at the index operation. Clinical and radiological evaluations were performed according to the methods of Merle d’Aubigné and Postel, Johnston et al. and DeLee and Charnley.

Results

The overall Merle d’Aubigné hip score significantly improved (3.7 vs 10.4, p < 0.01). The limb length discrepancy decreased from 30 to 6 mm (p < 0.01). The average distance that the hip centre was distalised was 22.3 mm (0–56 mm). However, radiolucent lines were observed in 27 % of patients at final follow-up, and the overall rate of revision for aseptic loosening was 16 %. Further, Kaplan-Meier survivorship curves predicted a rapid increase in the failure rate at 15 years.

Conclusions

The mid-term functional outcome of THA with an acetabular roof-plasty using a bulk autograft is satisfactory; however, the long-term results are questionable.     

Outcomes of dual-mobility acetabular cup for instability in primary and revision total hip arthroplasty

Background

The concept of a dual-mobility hip socket involves the standard femoral head component encased in a larger polyethylene liner, which in turn articulates inside a metal shell implanted in the native acetabulum. The aim of this study was to assess outcomes from using a Serf Novae^® Dual Mobility Acetabular cup (Orthodynamics Ltd, Gloucestershire, UK) to address the problem of instability in primary and revision total hip arthroplasty (THA).

Materials and methods

A retrospective review was carried out of all hip arthroplasties performed in a District General Hospital utilising the dual-mobility socket from January 2007 to December 2012. Clinical and radiological outcomes were analysed for 44 hips in 41 patients, comprising 20 primary and 24 revision THA. The average age of the study group was 70.8 years (range 56–84 years) for primary and 76.4 years (range 56–89 years) for revision arthroplasty. Among the primary THA, always performed for hip osteoarthritis or in presence of osteoarthritic changes, the reasons to choose a dual mobility cup were central nervous system problems such as Parkinson’s disease, stroke, dementia (10), hip fracture (5), failed hip fracture fixation (2), severe fixed hip deformity (2) and diffuse peripheral neuropathy (1). The indications for revisions were recurrent dislocation (17), aseptic loosening with abductor deficiency (4), failed hemiarthroplasty with abductor deficiency (2) and neglected dislocation (1).

Results

At a mean follow-up of 22 months (range 6–63 months), none of the hips had any dislocation, instability or infection and no further surgical intervention was required. Radiological assessment showed that one uncemented socket in a revision arthroplasty performed for recurrent dislocation had changed position, but was stable in the new position. The patient did not have complications from this and did not need any surgical intervention.

Conclusions

Even though postoperative hip stability depends on several factors other than design-related ones, our study shows promising early results for reducing the risk of instability in this challenging group of patients undergoing primary and revision hip arthroplasty.

Level of evidence

IV.     

The accuracy of digital templating: a comparison of short-stem total hip arthroplasty and conventional total hip arthroplasty

Purpose

Selection of the correct femoral stem size is crucial in total hip arthroplasty for an uncomplicated implantation and good initial stability. Pre-operative templating has been shown to be a valuable tool in predicting the correct implant size. For short-stem total hip arthroplasty (SHA), which recently is increasingly used, it is unknown if templating can be performed as reliable as conventional total hip arthroplasty (THA).

Methods

A total of 100 hip arthroplasties, 50 with SHA and 50 with THA, were templated by four orthopaedic surgeons each. The surgeons had different levels of professional experience and performed a digital template of the acetabular and femoral component on the pre-operative radiographs. The results were compared with the truly inserted implant size.

Results

For the femoral stems the average percentage of agreement (±1 size) was 89.0 % in SHA and 88.5 % in THA. There was no significant difference among surgeons in the accuracy of templating the correct stem size and no significant difference between templating SHA and THA. For the acetabular component the average percentage of agreement (±1 size) was 75.8 %. However, the more experienced surgeons showed a significant higher accuracy for templating the correct cup size than the less experienced surgeons.

Conclusion

Digital templating of SHA can predict the stem sizes as accurately as conventional THA. Therefore digital templating is also recommendable for SHA, as it helps to predict the implant size prior to surgery and thereby might help to avoid complications.     

Is there an association between periprosthetic joint infection and low vitamin D levels?

Purpose

Vitamin D is increasingly being recognized as an important mediator of immune function and may have a preventive role in the pathogenesis of periprosthetic joint infection. To the best of our knowledge, no other study has examined possible associations between periprosthetic joint infection and vitamin D deficiency. We investigated the rate of vitamin D deficiency in patients treated for periprosthetic joint infection and whether vitamin D deficiency is independent of other risk factors for vitamin D deficiency in patients with periprosthetic joint infection.

Methods

Serum 25-hydroxyvitamin D (25OHD) levels of every patient scheduled to receive a total prosthesis either of the hip, knee, or shoulder in the orthopaedic department of the Johannes-Guttenberg-University Hospital in Mainz, Germany (109 patients), were measured after admission. Furthermore, serum 25OHD levels were measured for every patient presenting with periprosthetic joint infection (n = 50) or aseptic loosening of the prosthesis (n = 31) scheduled to undergo revision surgery. The prevalence of normal (>30 ng/ml), insufficient (20–30 ng/ml), and deficient (<20 ng/ml) 25OHD levels was determined.

Results

All tested patient subgroups showed low vitamin D levels. Statistical analysis found no significant difference in vitamin D levels comparing patients with prosthesis and patients with aseptic prosthesis loosening (p = 0.58). Significant differences in 25OHD levels were found comparing patients with periprosthetic joint infection and patients scheduled for primary arthroplasty (p < 0.001). In addition, we found a significant difference (p < 0,001) in 25OHD levels of patients with periprosthetic joint infection compared with patients with aseptic prosthesis loosening.

Conclusion

We found a high frequency of vitamin D deficiency in patients being treated by primary arthroplasty and those with aseptic joint prosthetic loosening and periprosthetic joint infection. Vitamin D deficiency was severe in patients with periprosthetic joint infection.     

Patients with no functional improvement after total knee arthroplasty show different kinematics

Purpose

As many as 20 % of all patients following total knee arthroplasty are not satisfied with the result. Rotational alignment is one factor thought to affect clinical outcome. The purpose of this study was to assess relationships between prosthesis rotational alignment, function score and knee kinematics after TKA.

Methods

In 80 patients a cemented, unconstrained, cruciate-retaining TKA with a rotating platform was implanted. Rotational alignment was measured using CT-scans. Kinematics was assessed using fluoroscopy images.

Results

Seventy-three patients were available for follow-up after two years. Nine patients had more than 10° rotational mismatch between the femoral and tibial component in the postoperative CT scans. These patients showed significantly worse results in the function score. While the normal patients with less than 10° rotational mismatch improved from a mean pre-operative 55 points to a mean 71 points at follow-up, the group with more than 10° mismatch deteriorated from a mean 60 points pre-operatively to a mean 57 points at follow-up. The pattern of motion during passive flexion from approximately 0° to 120° was quite different. While external rotation steadily increased with knee flexion in the normal group, there was internal rotation between 30° and 80° of flexion in the group with more than 10° rotational mismatch.

Conclusion

Rotational mismatch between femoral and tibial components exceeding 10° resulted in different kinematics after TKA. It might contribute to worse clinical results observed in those patients and should therefore be avoided.     

Application and survival curve of total hip arthroplasties: a systematic comparative analysis using worldwide hip arthroplasty registers

Purpose

The aim of the study was to compare primary total hip arthroplasty (THA) implantations between different countries in terms of THA number per inhabitant, age, and procedure type and to compare the survival curve including all THAs using hip arthroplasty registers.

Methods

THA registers were compared between different countries with respect to the number of primary implantations per inhabitant and age, procedure type and survival curve. We performed a literature search for all national hip arthroplasty registers providing annual reports for 2009 or, if not available, a more recent period. The data from these reports were analysed in terms of number, age distribution and procedure type of primary THAs and survival curves.

Results

We identified nine hip arthroplasty registers, which comprised sufficient data to be included. A large variation was found in the annual number of primary THA implantations per inhabitant. The procedure type varied greatly as well, e.g. in Sweden 67 % are cemented THAs whereas in Emilia-Romagna (Italy) 89 % are cementless THAs.

Conclusions

This study revealed large differences in terms of the annual number of primary THAs per inhabitant and primary THA procedure type across countries. These data can be used to rank local primary THA implantations within an international context.     

Is it Time for Cementless Hip Resurfacing?

Background

Metal-on-metal bearing with cemented femoral component and cementless acetabular fixation is the current standard in surface replacement arthroplasty (RSA) of the hip. Because of concerns about the long-term survivorship of cemented stems in conventional hip arthroplasty, it seems logical to achieve cementless fixation on the femoral side with RSA.

Questions/Purposes

The goals of this review were to evaluate clinical and radiological data reported from previously published cementless RSA series. In addition, we intend to review author’s preliminary experience with Conserve Plus cementless devices specifically assessing the clinical outcomes, the complications rate, the survivorship, and the metallic ions levels measured in follow-up.

Methods

A references search was done with PubMed using the key words “cementless hip resurfacing”, “cementless hip resurfacing prosthesis”, and “femoral cementless hip resurfacing”. Additionally, the clinical outcomes, the complications rate, the survivorship, and the metallic ions levels were measured in 94 cementless Conserve Plus^© devices in 90 patients (68 males and 22 females) with a mean age of 41.1 years (18–59). Mean follow-up was 13.1 months (8–16).

Results

No revision was performed during the observed follow-up. Neither radiological signs of loosening nor neck narrowing >10% were evident. Chromium and cobalt levels in whole blood samples rose respectively from 0.53 μg/l (0.1–1.7) to 1.7 μg/l (0.6–2.9) and from 0.54 μg/l (0.1–1.4) to 1.98 μg/l (0.1–2.8).

Conclusions

Cementless “fit and fill” femoral-side fixation, which seems to be potentially evolved and design-related, should be considered for future hip-resurfacing device generations.     

New method for measuring acetabular component positioning with EOS imaging: feasibility study on dry bone

Purpose

Malposition of the acetabular cup is the most common cause of total hip arthroplasty (THA) dislocation. The position of a total hip implant is usually analysed on computed tomography (CT) scan. We aim to prove it is possible to measure, with good accuracy, the position of an acetabular cup using the low-dose irradiation (EOS) imaging.

Material and methods

We implanted an acetabular cup in a pelvic dry bone and measured cup anteversion and inclination with scanography. We performed 14 series of EOS acquisitions with different inclination, rotation and pelvic tilt, which were analysed by five observers. Two observers repeated angle measurements. We then calculated measurement inter- and intrareproducibility and accuracy.

Results

Using a confidence interval (CI) of 95 %, inter- and intra-observer reproducibility were ±1.6, and ±1.4°, respectively, for cup inclination; accuracy in comparison with CT was ±2.6°. Using a 95 % CI, inter- and intra-observer reproducibility for cup anteversion were ±2.5° and ±2.3°, respectively. Measurement accuracy compared with CT was ±3.9°.

Conclusion

EOS imaging system is superior to standard radiography in terms of measuring acetabular anteversion and inclination.     

Targeted pre-operative autologous blood donation: a prospective study of two thousand and three hundred and fifty total hip arthroplasties

Purpose

Pre-operative donation of autologous blood has been widely used in elective joint replacement procedures to avoid the risks of allogeneic blood transfusions. However, the high percentage of wasted autologous blood questions the general efficacy of pre-operative autologous blood donation (PABD) for all patients undergoing hip replacement. This study prospectively investigates the impact of a targeted pre-operative autologous blood donation protocol for anaemic patients on allogeneic and overall transfusion rates in 2,350 unilateral primary total hip arthroplasty procedures.

Methods

Patients with pre-operative haemoglobin less than 12.5 g/dL were advised to donate one unit of autologous blood seven to 15 days prior to the date of surgery. The targeted protocol was followed by 2,251 patients: 280 out of 367 anaemic patients donated while 1,971 out of 1,983 non-anaemic patients did not donate.

Results

Results showed a significantly lower rate of allogeneic transfusion for anaemic patients who predonated than anaemic patients who did not (13 % vs. 37 % respectively, p < 0.001). Overall transfusion rates for patients who followed the protocol (n = 2,251) were found to be 0.17 units/patient compared to previously reported numbers of 0.75 units/patient when routine donation was used. Among the 2,251 patients who followed the protocol, only 140 patients (6 %) had their autologous blood wasted, in contrast to values reported in the literature ranging from 14 % up to 50 %.

Conclusions

Targeted PABD reduces the need for allogeneic blood transfusion in anaemic patients and significantly reduces the overall number of transfusions compared to routine pre-operative autologous donation.     

A Mid-Term Analysis Suggests Ceramic on Ceramic Hip Arthroplasty Is Durable with Minimal Wear and Low Risk of Squeak

Background

The incidence of hip replacements in the younger patient is ever increasing. With this in mind, improving the longevity of hip arthroplasties is paramount. Alumina ceramic is a promising bearing surface due to its low wear rate and biological inertness.

Purpose

This study aims to review our experience with ceramic-on-ceramic total hip arthroplasty, reporting on the need for revision as well as the cause of failure. Our secondary purpose is to review our experience with the phenomenon of squeaking analysing and its effect on clinical outcome with specific emphasis on component positioning. Also reported are the results of our retrieval analysis of explanted components documenting the wear rate and our analysis of strip wear.

Methods

A consecutive series of 301 primary cementless alumina-on-alumina total hip arthroplasties at a minimum of 10 years follow-up was reviewed. These arthroplasties all had third-generation ceramic-on-ceramic bearings performed through a posterior approach with repair of capsule and external rotators to bone. We analysed hips both clinically and radiographically. Analysis of wear in 62 ceramic bearings was performed using a Roundtest RA300 machine (Mitutoyo; Andover, UK), which has an accuracy of 0.01 μm.

Results

Overall, the survival rate of the implants was 98% at 10 years. No ceramic fractures were encountered in this study. Seventy-four patients reported squeaking hips, and two cases were revised due to squeaking (0.6%). No failures were related to bearing wear.

Conclusions

We believe that ceramic-on-ceramic is a safe bearing coupling with excellent survivorship at 10 years.