Immediate weightbearing after uncemented total hip arthroplasty

Early unrestricted vs. partial weight bearing after uncemented total hip arthroplasty: a systematic review and meta-analysis

Background

The choice of postoperative weight bearing protocol after uncemented total hip arthroplasty (THA) remains controversial. The aim of this study was to assess the efficacy and safety of immediate unrestricted weight bearing (UWB) compared with partial weight bearing (PWB) in patients undergoing uncemented THA.

Methods

Relevant articles were retrieved from electronic databases. Both randomized controlled trials (RCTs) and non-RCTs were included but analyzed separately. All functional and clinical outcomes with at least 2 independent study outcomes were meta-analyzed.

Results

A total of 17 studies were investigated. No adverse effect was found regarding micromotion of the femoral stem with immediate UWB following uncemented THA. There was also no correlation between immediate UWB and failure of ingrowth fixation and higher risks of femoral stem subsidence and surgical revision in RCTs. Harris hip score was better in patients with immediate UWB than those with PWB at 1 year post surgery, but the difference was not statistically significant.

Conclusions

Immediate UWB did not have extra harm compared with PWB in patients undergoing uncemented THA. UWB was not superior to PWB. Considering the improvement of Harris score and the compliance of patients, UWB can be encouraged in THA rehabilitation.

Penalty for Switching Implants? Assessing the Learning Curve With a Collarless, Tapered Wedge Cementless Femoral Component

Background

Surgeon learning curve associated with a tapered wedge femoral implant as measured by early femoral component subsidence and 90-day risk of reoperation was evaluated.

Methods

The first 451 patients undergoing primary, cementless total hip arthroplasty by a single, fellowship-trained arthroplasty surgeon with a tapered wedge stem design were retrospectively reviewed. Early radiographic femoral component subsidence during the first 6 weeks postoperatively and 90-day reoperations was recorded.

Results

When stratified by approach, there was no association between date of surgery and femoral component subsidence in the posterior approach (P-value for linear trend over time = 0.44). In the direct anterior approach, there was a significant association between date of surgery and early femoral component subsidence (P-value for linear trend over time = 0.01). For both approaches, there was an increase in implanted stem size relative to templated stem size over time (P < .01 and P = .03, respectively). There was no association between the date of surgery and risk of 90-day reoperation (P = .45).

Conclusions

In a single surgeon's initial use of a tapered cementless wedge stem, early femoral component subsidence was not impacted by the surgeon's learning curve when the posterior approach was utilized. Although subsidence was associated with date of surgery in the direct anterior cohort, this was not associated with increased risk of 90-day reoperation. Should a surgeon adopt a new tapered-wedge stem, these findings suggest that the stem is forgiving both in relation to subsidence and 90-day reoperation risk when appropriate surgical technique is utilized.

Does femoral stem choice influence fracture type or incidence for direct anterior approach total hip arthroplasty?

INTRODUCTION

Despite similar fracture rates, the incidence of intraoperative and post-operative fractures between standard (ST) length and short (SH) femoral stems remains unclear. Therefore, this study compared the incidence of intraoperative and early postoperative fractures between three ST and a single tapered-wedge SH femoral stem.

MATERIALS AND METHODS

Data were retrospectively collected on 1113 patients (1306 hips) having undergone total hip arthroplasty, via the anterior approach on a fracture table, between 2014 and 2019. One surgeon completed all ST procedures (314 hips), using one of three implants without discretion. One surgeon completed all SH procedures (992 hips), using one implant design. Differences between ST and SH groups were evaluated by independent t tests (continuous variables) and Chi-square tests (categorical variables).

RESULTS

Patients in the SH group were significantly older (p < 0.001) and had a lower body mass index (p = 0.001) compared to the ST group. The total number of fractures was 12 (3.8%) and 14 (1.4%) in the ST and SH groups, respectively. The 12 ST fractures occurred intraoperatively, compared to two (0.2%) in the SH group. The remaining seven (0.7%) SH fractures occurred post-operatively. There was no difference in fracture rate between the three ST designs (p = 0.882). Interestingly, five (0.5%) insufficiency fractures were diagnosed in the SH group.

CONCLUSION

The risk of intraoperative and post-operative fractures following anterior total hip arthroplasty may be biased toward ST and SH implants, respectively. These results, along with the presence of five insufficient fractures, identify potential fracture risks and mechanisms for specific implant designs.

Neocortex Formation in a Tapered Wedge Stem is Not Indicative of Complications or Worse Outcomes

BACKGROUND

The formation of sclerotic bone, a neocortex, distally surrounding total hip arthroplasty (THA) stems may commonly be seen on radiographs around proximally porous coated stems but can be confused with loosening. The goal of this study was to determine the prevalence of the neocortex finding and whether it associated with worse outcomes after THA.

METHODS

A retrospective review of 825 patients with a single tapered wedge stem was performed. Radiographs at 1-year, as well as final follow-up were reviewed for evidence of sclerotic bone (neocortex) surrounding the stem in all 14 Gruen zones. The final attending radiology read of lucency was also recorded. Patients were grouped by the presence of the neocortex. PROMIS Physical Function scores and complications were compared between neocortex groups.

RESULTS

The neocortex group had 558 (68%) patients compared to 267 (32%) in the no neocortex group. The most common Gruen zones for evidence of neocortex were 10 (55%), 11 (52%), and 12 (51%). Seven percent of patients had a finding of lucency on radiology read. There was no difference between groups in terms of dislocations (P = .61), infection (P = .79), fracture rates (P = .54), revision surgery (P = .73), and reoperation for any cause (P = .62). PROMIS PF scores were significantly higher in the neocortex group (P < .0001).

CONCLUSION

The presence of a distal neocortex is a common finding on radiographs after THA with this proximally porous-coated tapered wedge stem and does not portend worse outcomes, nor is it a sign of aseptic loosening, increased revision rates, infection, dislocation, or periprosthetic fracture risk.

Differences in femoral component subsidence rate after THA using an uncemented collarless femoral stem: full weight-bearing with an enhanced recovery rehabilitation versus partial weight-bearing

BACKGROUND

Femoral component subsidence is a known risk factor for early failure of total hip arthroplasty (THA) using cementless stems. The aim of the study was to compare an enhanced recovery concept with early full weight-bearing rehabilitation and partial weight-bearing on stem subsidence. In addition, the influence of patient-related and anatomical risk factors on subsidence shall be assessed.

METHODS

One hundred and fourteen patients underwent primary cementless THA and were retrospectively analyzed. Sixty-three patients had an enhanced recovery rehabilitation with early full weight-bearing and 51 patients had rehabilitation with partial weight-bearing (20 kg) for 6 weeks. Postoperative subsidence was analyzed on standing pelvic anterior-posterior radiographs after 4 weeks and 1 year. Subsidence was measured in mm. Anatomical and prosthetic risk factors (stem size, canal flare index, canal fill ratio as well as BMI and demographic data) were correlated.

RESULTS

Femoral stem subsidence rate was significantly higher for the group with an enhanced recovery concept compared to the group with partial weight-bearing at the first radiological follow up after 4 weeks [2.54 mm (SD ± 1.86) vs. 1.55 mm (SD ± 1.80)] and the second radiological follow up after 1 year [3.43 mm (SD ± 2.24) vs. 1.94 (SD ± 2.16)] (p < 0.001, respectively). Stem angulation > 3° had a significant influence on subsidence. Canal flare index and canal fill ratio showed no significant correlation with subsidence as well as BMI and age.

CONCLUSION

In the present study, cementless stem subsidence was significantly higher in the group with enhanced recovery rehabilitation compared to partial weight-bearing. Small absolute values and differences were demonstrated and therefore possibly below clinical relevance. Anatomical radiological parameters and anthropometric data did not appear to be risk factors for stem subsidence.

Long-term bone remodelling around 'legendary' cementless femoral stems

Bone remodelling around a stem is an unavoidable long-term physiological process highly related to implant design. For some predisposed patients, it can lead to periprosthetic bone loss secondary to severe stress-shielding, which is thought to be detrimental by contributing to late loosening, late periprosthetic fracture, and thus rendering revision surgery more complicated.However, these concerns remain theoretical, since late loosening has yet to be documented among bone ingrowth cementless stems demonstrating periprosthetic bone loss associated with stress-shielding.Because none of the stems replicate the physiological load pattern on the proximal femur, each stem design is associated with a specific load pattern leading to specific adaptive periprosthetic bone remodelling. In their daily practice, orthopaedic surgeons need to differentiate physiological long-term bone remodelling patterns from pathological conditions such as loosening, sepsis or osteolysis.To aid in that process, we decided to clarify the behaviour of the five most used femoral stems. In order to provide translational knowledge, we decided to gather the designers' and experts' knowledge and experience related to the design rationale and the long-term bone remodelling of the following femoral stems we deemed 'legendary' and still commonly used: Corail (Depuy); Taperloc (Biomet); AML (Depuy); Alloclassic (Zimmer); and CLS-Spotorno (Zimmer). Cite this article: EFORT Open Rev 2018;3:45-57. DOI: 10.1302/2058-5241.3.170024.

Partial versus early full weight bearing after uncemented total hip arthroplasty: a meta-analysis

BACKGROUND

This meta-analysis aimed to investigate the efficacy and safety of partial weight bearing (PWB) versus early full weight bearing (FWB) after uncemented total hip arthroplasty (THA).

METHODS

We conducted a search in PubMed, EMBASE, The Cochrane Library, and Web of Science for randomized controlled trials (RCTs) and non-RCTs comparing PWB and early FWB after uncemented THA. Two authors conducted the selection of studies, data extraction, and assessment of risk of bias independently. A pooled meta-analysis was performed using the RevMan 5.3 software.

RESULTS

Six RCTs and three non-RCTs met the inclusion criteria. The meta-analysis indicated that compared with PWB, the FWB group showed greater femoral subsidence at 3-month follow-up (MD = -0.12, 95% CI -0.22 to -0.01, P = 0.03). There were no significant differences in the hip Harris score at 1-year and 2-year follow-up (MD = 1.54, 95% CI -0.83 to 3.90, P = 0.20; MD = 0.08, 95% CI -1.19 to 1.34, P = 0.90, respectively), in femoral subsidence at 2-year follow-up and at two additional years of follow-up (MD = -0.03, 95% CI -0.31 to 0.25, P = 0.84; (MD = -0.02, 95% CI -0.37 to 0.33, P = 0.91, respectively). There were no significant differences in the incidences of bone ingrowth fixation, spot welds, and radiolucent lines.

CONCLUSIONS

This meta-analysis shows that early FWB in patients with uncemented THA could be safe and could not increase the incidence of postoperative complications.

[Rehabilitation after hip and knee endoprosthetic treatment in the elderly]

Due to current demographic developments with a continuous increase in average life expectancy and improved medical treatment, the number of elderly patients with joint replacement of the lower extremities also has increased in recent years. Most of these patients have not only one but several chronic diseases requiring treatment and medication. Drug-drug interaction and functional restrictions of the elderly additionally reduce the postoperative psychophysical capacity; therefore, special knowledge in rehabilitative treatment and pain management is necessary. Physiotherapy and exercise should include training of mobility, endurance, strength, coordination and training in activities of daily living. The individual constitution and pain during exercise must always be taken into consideration. Rehabilitative outcome is dependent on a functioning cooperation of an interdisciplinary rehabilitation team and requires an organized, holistic treatment approach in interconnected structures, which aims at rapid postoperative mobilization.

The Importance of Bone Mineral Density in Hip Arthroplasty: Results of a Survey Asking Orthopaedic Surgeons about Their Opinions and Attitudes Concerning Osteoporosis and Hip Arthroplasty

Objective. In patients scheduled to undergo total joint arthroplasty of the hip, the bone quality around the joint affects the safety of prosthetic implantation. Bone strength is clinically assessed by measuring bone mineral density (BMD); therefore we asked if BMD is important to orthopaedic surgeons performing hip arthroplasty. Methods. In a 14-question survey, we asked about treatment patterns with respect to BMD, osteoporosis work-up, and treatment for patients with low BMD scheduled to undergo hip arthroplasty. Results. 72% of all asked orthopaedics reported to use cementless implants as a standard in hip arthroplasty. Over 60% reported that low BMD is a reason to reconsider operation strategies, but only 4% performed BMD measurement preoperatively. 26% would change their treatment strategy in case of a BMD (T-Score) between −1.5 and −2 and 40% in case of a T-score between −2 and −2.5, and 29% would change their intraoperative strategy if a T-score smaller than −2.5 was measured. Conclusion. The majority of orthopaedic surgeons who responded to the survey reported that they do not perform routine measurement of BMD before arthroplasty. However, most surgeons commented that low bone mineral density will influence their surgical plan and the implant design.

New Approach and Stem Increased Femoral Revision Rate in Total Hip Arthroplasty

This study compared the femoral stem revision and loosening rates in primary total hip arthroplasty between 2 different approaches and stem designs. Recent reports comparing the direct anterior approach with either the posterior or lateral approach showed that patients undergoing the direct anterior approach have less pain and an accelerated functional recovery in the early postoperative period. After converting to an anterior approach, the authors observed an increased rate of femoral stem revision. From 2003 to 2009, a posterior or lateral approach was used to insert 514 stems of 2 designs. These cases included the use of an extensively coated cobalt-chrome stem (n=232) or a straight, dual-tapered, proximally porous-coated titanium stem (n=282). In the following years, from 2009 to 2012, 594 short, proximally coated, titanium tapered-wedge stems were inserted through a direct anterior approach. The revision rates of femoral stems inserted through a posterior approach or a lateral approach were compared with those inserted via a direct anterior approach. No stem revisions occurred in the posterior approach group or the lateral approach group, and 5 stems were revised in the anterior approach group for periprosthetic fracture or aseptic loosening (0.8%). Significantly more stem revisions occurred after the use of the new stem design and a direct anterior approach (P=.04).

Unrestricted Weight Bearing and Intensive Physiotherapy after Uncemented Total Hip Arthroplasty

Background and Aims:

The effectiveness of partial weightbearing after hip surgery has been questioned as well as the need of intensive physiotherapy.

Material and Methods:

36 patients (average age 54.4, 19 women) operated with uncemented hip arthroplasty were randomized either to unrestricted weightbearing (UWB) combined with intensive physiotherapy or to partial weightbearing (PWB) for 3 months combined with a short self-training program. The load during walking and the muscle strength (MS) in abduction was measured preoperative and subsequent up to 12 months.

Results:

The average peak load on the operated leg at one week was 39.0 kg for the UWB and 25.8 for the PWB group (P = 0.009) while at three months 70.0 and 31.7 (P = 0.001) respectively. At 6 and 12 months there were no differences between the groups. The muscle strength increased in both groups up to six months but there were no differences between the groups.

Conclusions:

Even though patients applied more load than the recommended 15 kg most patients were able to comply with partial weightbearing fairly well. The effect of intensive physiotherapy on the muscle strength after hip arthroplasty is questionable.

Return to sports activity with short stems or standard stems in total hip arthroplasty in patients less than 50 years old

BACKGROUND

The aim of this study was to compare return to sport activity between a short femoral cementless stem and a conventional femoral cementless stem in total hip arthroplasty in patients 50 years old and younger.

METHODS

We retrospectively reviewed 55 patients (61 hips) treated with a short femoral cementless stem and 28 patients (32 hips) treated with a conventional femoral cementless stem 50 years old and younger from December 2009 and December 2014.Their mean age was 39.86 (22-49) years and 38.68 (18-49) years, respectively. The mean follow-up was 54.1 (15-68) months and 52.7 (15-72) months, respectively. They were pre- and postoperatively evaluated by the clinical and radiological examination.

RESULTS

No patients with the short stem had intraoperative fracture, but 1 patient with the conventional stem had intraoperative fracture. At final follow-up, there was no statistically significant difference in Harris Hip Score, and radiographic review level between 2 stems. No hip with the short stem had thigh pain, but 6 hips with the conventional stem had thigh pain at the final follow-up. No component was revised for aseptic loosening in either group. There were no differences observed in the return to sports activity between the 2 groups.

CONCLUSIONS

Our study demonstrated that both short cementless stem and conventional cementless stem provided stable fixation and achieved a satisfactory result in patients 50 years old and younger. There is no difference in return to sports activity level after the procedure.

One-stage bilateral versus unilateral short-stem total hip arthroplasty: comparison of migration patterns using "Ein-Bild-Roentgen-Analysis Femoral-Component-Analysis"

PURPOSE

The hypothesis of this study was that femoral implant migration would not differ between simultaneous bilateral or unilateral short-stem THA.

METHOD

Implant migration of 202 femoral short-stems (100 unilateral and 102 one-stage bilateral cases) in 151 patients was assessed by "Ein-Bild-Roentgen-Analysis Femoral-Component-Analysis" in a two years follow-up (2.0-3.0 years). Migration patterns of unilateral and simultaneous cases were analysed and compared.

RESULTS

There was no difference between the two groups regarding age, body mass index and gender. After two years mean subsidence of all 202 implants was 1.43 mm (-6.5 mm to 2.0 mm). After initial subsidence of 0.37 mm per month within the first six weeks, the mean monthly migration was reduced to 0.02 mm between one and two years post-operative. There was no statistical difference in mean migration between unilateral (1.34 mm) and simultaneous bilateral (1.51 mm) THA (p = 0.33).

CONCLUSION

In summary, two years post-operative there was no difference in the amount of mean implant subsidence between unilateral compared to simultaneous bilateral short-stem THA. This suggests that regarding implant fixation simultaneous bilateral short-stem THA is as safe and successful as a solely unilateral intervention.

Can a Conical Implant Successfully Address Complex Anatomy in Primary THA? Radiographs and Hip Scores at Early Followup

BACKGROUND

Total hip arthroplasty (THA) in patients with small or abnormal proximal femoral anatomy is challenging as a result of complex anatomic deformities in the hip. It is unclear which stem is the most appropriate for these patients. One possible implant design that may help meet this need is the modified Wagner Cone prosthesis, whose design consists of monoblock cone with splines; however, to our knowledge, no clinical results have been published using this implant.

QUESTIONS/PURPOSES

We evaluated the hip scores and radiographic results (including signs of osseointegration and subsidence) of complex primary THA using the modified Wagner Cone cementless femoral component in patients with small or abnormal proximal femoral anatomic proportions.

METHODS

Between 2006 and 2011, we performed 59 THAs on patients whose femoral geometry precluded the use of standard-sized implants. Of these, 49 (83%) received the modified Wagner Cone prosthesis. During this time, our indications for use of the Wagner Cone implant in such patients included: femoral neck retroversion, excessive anteversion of the femoral neck, or small proximal femora not suitable for standard implants. Of those, 40 patients with 49 THAs were available for radiographic and clinical followup at a minimum of 3 years, and no patients were lost to followup. The diagnosis included developmental dysplasia of hip (22 patients, 28 hips), secondary trauma or posttuberculosis osteoarthritis (nine patients, 10 hips), and hip disease secondary to other disorders (eight patients, nine hips) and osteonecrosis (one patients, two hips). Two versions of the stem with 135° (28 hips) or 125° (21 hips) neck angle versions were used to reestablish normal hip biomechanics. Version angle was chosen based on preoperative templating. Cementless cups with screws were used for the acetabulum. Mean followup was 4 years (range, 3-7 years). Study endpoints were the Harris hip score and radiographic evaluations by a surgeon not involved in the clinical care of the patients (QZ); radiographic analysis included evaluating for the presence or absence of signs of osseointegration (including Engh's criteria) and subsidence.

RESULTS

The Harris hip score improved from a mean of 41 ± 9 preoperatively to a mean of 85 ± 10 at last followup (p < 0.01). The mean vertical subsidence was 1.5 ± 1.1 mm. Radiographic evaluation demonstrated stability (no further subsidence) of all implants at last followup. Endosteal spot welds were found in 32 hips (65%). No progressive radiolucencies were observed. One patient (one hip) underwent revision surgery as a result of late infection; no other revisions were performed.

CONCLUSIONS

The modified Wagner Cone femoral stem has provided improvements in hip scores and promising short-term radiographic results at short-term followup in complex cementless THA associated with abnormal or small femoral anatomical proportions in which standard implants are inappropriate. Longer followup will be needed to see if these results endure. Randomized trials are needed to determine the optimal stem design for these patients.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Osseointegration of Ti-6Al-4V alloy implants with a titanium nitride coating produced by a PIRAC nitriding technique: a long-term time course study in the rat

This study examined bone tissue responses to Ti-6Al-4V alloy implants with a hard TiN coating applied by an original powder immersion reaction-assisted coating (PIRAC) nitriding method. Progression of implant fixation in the distal epiphysis and within the medullary cavity of the rat femur was evaluated between 3 days and 6 months postimplantation by scanning electron microscopy, oxytetracycline incorporation, and histochemistry. After 6 months, successful osseointegration was achieved in both epiphyseal and diaphyseal sites. Throughout, implant portions located within the epiphysis remained in close contact with bone trabeculae that gradually engulfed the implant forming a bone collar continuous with the trabecular network of the epiphysis. In the diaphysis, woven bone was first formed within the marrow cavity around the implant and later was replaced by a shell of compact bone around the implant. In general, higher osseointegration rates were measured for TiN-coated versus the uncoated implants, both in the epiphysis and in the diaphysis. In conclusion, our findings indicate an excellent long-term biocompatibility of TiN coatings applied by the PIRAC nitriding technique and superior osteoinductive ability in comparison with uncoated Ti-6Al-4V alloy. Such coatings can, therefore, be considered for improving the corrosion and wear resistance of titanium-based orthopedic implants.

Cementless bipolar hemiarthroplasty using a micro-arc oxidation coated stem in patients with displaced femoral neck fractures

Femoral stem fixation for displaced femoral neck fractures in osteoporotic patients is an ongoing debate. We evaluated the outcome of 136 cementless bipolar hemiarthroplasty using a Micro-arc oxidation (MAO) coated stem. All patients survived the procedure and were discharged from the hospital. Thirty- and 90-day mortality rates were 0.7% and 2.2%, respectively. Ninety-eight hips were followed for a minimum of 2years (mean, 44months) postoperatively. Three stems were revised because of a periprosthetic fracture. Although cortical stress shielding around the stem was observed in 3 hips, there was no loosening or osteolysis. Cementless bipolar hemiarthroplasty using a MAO-coated stem is a useful and safe option to treat displaced femoral neck fractures.

Clinical comparison of THA with a standard-length or short femoral component

The purposes of this 2-part study were to determine whether reduced distal femoral component geometry allows for routinely larger component sizes to be used and whether clinical or radiographic outcomes differ between total hip arthroplasty (THA) patients treated with either standard-length or short femoral components. Femoral component size and ongrowth surface area were retrospectively compared in a group of bilateral THA patients that had both a standard-length component and a contralateral short component. Then, clinical and radiographic outcomes were compared between matched groups of THA patients that had either a standard-length or short femoral component. The use of the short component resulted in a significantly larger femoral component size being used (P=.01), and the potential ongrowth surface area was significantly larger for the short component than for the standard component (median, 36.69 vs 35.55 cm2; P=.02). In the matched-pairs analysis, no group differences were noted in modified Harris Hip Scores (P=.43) or femoral component subsidence (P=.35), but there was a significantly greater prevalence of radiolucent lines in Gruen zone 8 with the short component (P=.008). The use of a short femoral component was associated with consistently larger component sizes being used, which corresponded with a larger potential ongrowth surface area. Short-term clinical and radiographic outcomes did not differ between standard-length and short femoral components. Studies are necessary to determine whether the increased proximal ongrowth surface area may result in improved long-term fixation or, on the contrary, may increase the risk of periprosthetic fracture.

Effect of immediate full weight bearing on abductor repair and clinical function after THA through a modified Hardinge approach

This study evaluated the effect of immediate full weight bearing on abductor repair and clinical function after total hip arthroplasty (THA) using a direct lateral (modified Hardinge) approach. The surgical approach detached a bone flake with the abductors, providing a radiographic marker for abductor displacement and healing. Patients in whom weight bearing was restricted for 6 weeks (partial-weight bearing group) were compared with patients who were immediately weight bearing (full-weight bearing group). A total of 307 patients (309 hips) were followed for a mean of 14 months (range, 12-36 months). The partial-weight bearing group (163 patients) underwent 6 weeks of partial weight bearing, and the full-weight bearing group (146 patients) underwent immediate full weight bearing. The abductor repair was assessed radiographically via the bone flake harvested with abductor muscles. Nonunion of the abductor bone was observed in 12 (7%) patients in the partial-weight bearing group and 9 (6%) patients in the full-weight bearing group (P=.55). Patients in the full-weight bearing group had significantly earlier discharge from hospital than the partial-weight bearing group (2.6 vs 3.5 months, respectively; P=.0021). Patients in the full-weight bearing group had a higher mean Engh score (6.58) radiographically than did patients in the partial-weight bearing group (4.92) (P=.0005). No difference was observed in Harris Hip Score, limp, thigh pain, high-grade heterotopic bone, trochanteric bursitis, or stem subsidence between groups. Restricting weight bearing postoperatively to protect the Hardinge abductor repair appears unnecessary, and recovery of activity is improved with immediate weight bearing.

Does osteoporosis increase early subsidence of cementless double-tapered femoral stem in hip arthroplasty?

Among 320 hip arthroplasties performed between January 2007 and March 2008, patients younger than 50 years old and patients older than 70 with a T-score at the proximal femur less than -2.5 made up the control and study group, respectively. There were 40 patients in each group. We measured stem subsidence, both digital and manual methods. Measurements were made from radiographs taken serially from 2 weeks to 1 year after surgery. The amount of mean subsidence for each group was not different, and all stems showed stable fixation in the final radiographs. Our study suggests that even in osteoporotic proximal femurs, press-fit fixation of double-tapered stems for hip arthroplasty can be safe and effective without excessive early subsidence.

Does a collar improve the immediate stability of uncemented femoral hip stems in total hip arthroplasty? A bilateral comparative cadaver study

The aim of this study was to compare the immediate stability of collared vs collarless uncemented femoral stems in total hip arthroplasty. A bilateral comparative study of 20 cadavers (40 hips: 20 collarless, 20 collared) was performed. Forces in the vertical and horizontal planes required to initiate subsidence of femoral stem and subsequent femoral fracture were measured. In vertical plane, subsidence began at an average force of 3129 ± 494 N for collarless stems and 6283 ± 3584 N for collared stems (P = .02). Fracture occurred at a significantly higher force for collared stems (P = <.001). In horizontal plane, subsidence began at an average force of 540 ± 170 N for collarless stems and 678 ± 206 N for collared stems (P = .01). Fracture occurred at a significantly higher force for collared stems (P = .005). Collared uncemented stems have significantly greater immediate stability than collarless. They are able to withstand greater vertical and horizontal forces before the initiation of subsidence and subsequent fracture.

Outcome of the cementless Taperloc stem: a comprehensive literature review including arthroplasty register data

BACKGROUND AND PURPOSE

The validity of various data sources for the assessment of the outcome quality of medical devices was investigated by comparative analysis of the published data sources available for a sample of implants. It was the aim of the study to determine the performance of this implant and to identify potential bias factors inherent to the various datasets.

METHODS

A comprehensive literature search was carried out from English-language, peer-reviewed journals and worldwide reports from national arthroplasty registers. Publications from Medline-listed journals were included. The main parameter was revision rate, calculated as "revisions per 100 observed component years" to allow adjusted direct comparison of different datasets.

RESULTS

Of 16 clinical studies that met the inclusion criteria, 9 originated from the implant developer's hospital. In the clinical studies category, publications from the developer's hospital suggested considerably lower revision rates than the other datasets. In fact, the values quoted were 5.5 times below the average of all other studies, and 9.51 times lower than in the Australian arthroplasty register. These differences are statistically significant.

INTERPRETATION

The cementless Taperloc stem is an implant that shows good performance regarding revision rates in registry data and in clinical studies. However, the excellent results published by the developer's clinic are generally not reproducible by other surgeons. In terms of reference data, registry data are able to make an important contribution to the assessment of clinical sample-based studies, particularly regarding evaluation of the extent to which published results are reproducible in daily routine.

Partial weightbearing is not necessary after cementless total hip arthroplasty: a two-year prospective randomized study on 100 patients

The purpose of this study was to evaluate the effects of partial and full weightbearing after cementless total hip arthroplasty over a two year follow-up period. Fifty-nine women and 41 men (average age 61 years) received an uncemented Spotorno stem and were randomised into a full and a partial weightbearing group. No significant difference was found between the groups with regard to the Merle d' Aubigne hip score, VAS pain level, shaft migration or radiographic signs of bony ingrowth. All femoral components seemed radiologically well-fixed and showed bone ingrowth at 24 months. Provided that solid initial fixation is obtained full weightbearing immediately after cementless total hip arthroplasty using a hydroxyapatite-coated Spotorno-type femoral shaft component can be recommended.

Partial versus unrestricted weight bearing after an uncemented femoral stem in total hip arthroplasty: recommendation of a concise rehabilitation protocol from a systematic review of the literature

The aim of this systematic review was to find evidence-based support in the literature to allow immediate unrestricted weight bearing after primary uncemented total hip arthroplasty (THA). Accelerated rehabilitation programs for THA are becoming increasingly popular to shorten hospital stay and to facilitate rapid restoration of function. The goals of these rehabilitation programs could be more easily achieved if immediate unrestricted weight bearing (UWB) could be allowed after a THA. So far, however, immediate weight bearing is frequently contraindicated in widely accepted protocols for uncemented THA due to fear for subsidence and absence of osseous integration of the femoral stem. Thus, frequently protected weight bearing and restricted activities are still advocated for at least 6 weeks after surgery. In addition, we analyzed the literature to come to a recommendation on gait pattern and walking aid. From a systematic search in several electronic databases 13 studies met the inclusion criteria. These studies were reviewed according to the Cochrane methodology. We found moderate to strong evidence that no adverse effects on subsidence and osseous integration of the femoral stem after uncemented THA occur after immediate UWB. Based on this literature review, we recommend early rehabilitation after uncemented THA with a reciprocally gait pattern using crutches, one cane for independency in ADL in case patients walk limp-free and walking without crutches as soon as possible. During the first weeks after surgery only stair climbing should be performed with protected weight bearing because of high torsion loads on the hip.

[The standard implantation of a total hip prosthesis via two incisions (the Yale Technique)]

OBJECTIVE

Implantation of a total hip endoprosthesis with minimal trauma to the soft tissue. The need for visual aids (e.g., navigation or X-rays) during the procedure is frequently avoided.

INDICATIONS

All kinds of coxarthrosis for every age group, for every variation of bone construction, and even in obese patients.

CONTRAINDICATIONS

Extremely dysplastic hip joints involving the development of a secondary socket and the necessity of reconstruction of the acetabular socket (e.g., in the Harris method).

SURGICAL TECHNIQUE

Using a fixed lateral position, a small entry incision is made between the tensor fasciae latae and the sartorius muscles and the prosthesis socket is put into place. Via a second dorsal incision, after stripping the exterior rotators, the prosthesis stem and ball are implanted and the two parts of the prosthesis are attached.

POSTOPERATIVE MANAGEMENT

Full weight bearing allowed immediately. A luxation prophylaxis, in the form of a self-developed hip bodice (the so-called Yale bandage), is used until the end of the 4th postoperative week. Discharge from hospital is possible after just a few days. Upon discharge, the patient is sent to a rehabilitation facility, either as a resident or as an outpatient, for approximately 3 weeks. Return to the workplace, with only light physical activity, is possible once the wound has healed completely; this could be as soon as 14 days after the operation. Checkups are made after 4 weeks, 6 months, 1 year and then every year; these checkups include a full examination, X-rays and laboratory tests. Full exposure to sport or heavy manual labor is usually approved after the 6-month checkup.

RESULTS

Between October 2004 and April 2006, a total of 221 patients underwent surgery using this new technique (of these 15 patients underwent two-stage bilateral hip joint replacements). Patients were followed up for a minimum of 12 months and a maximum of 30 months. The Harris Hip Score improved from an average of 45.25 preoperatively to 96.4 postoperatively.

Is early weight bearing resumption beneficial after total hip replacement?

OBJECTIVE

Current rehabilitation protocols of patients following total hip replacement recommend weight bearing on the operated extremity as early as possible. This strategy is likely to induce specific consequences on postural balance control; this study seeks to highlight these reactions to early loading.

MATERIALS AND METHODS

Eight men and six women, ranging in age from 57 to 85 years, volunteered enrolling this study on their arrival at our rehabilitation center. This study assessed their postural behavior using a system composed of two separate force platforms under two loading situations; in the course of these tests they were required to minimize their body sway as much as possible by keeping their eyes open. In the natural uncontrolled situation, the subjects adopted a comfortable body weight distribution. In the imposed (IMP) situation, they had to load their operated extremity more than in regular natural conditions in order to distribute their body weight more evenly. Three successive 32-s trials (sampled at 64 Hz) with intermediate recovery periods of equivalent duration were performed allowing period of rest between each trial. The balance strategies were evaluated through a frequency analysis of the resultant and plantar centers of pressure (CP(Res)) of each foot and of the estimated trajectories of the vertical projection of the center of gravity (CG), and from the difference CP(Res)-CG.

RESULTS

No difference was found for the plantar CP trajectories in the situation where body weight is spontaneously distributed, whereas loading the implanted extremity induced increased CP(Res), CG, and CP(Res)-CG trajectory amplitudes along the mediolateral axis. No effect was observed along the anteroposterior axis. Finally, when comparing the two limbs for each testing condition, the statistical analysis demonstrated greater displacements along the ML axis for the trajectories measured under the healthy leg than under the implanted extremity.

DISCUSSION

Loading the operated extremity early in the rehabilitation process leads to less stability (an increase in the CG movements) and to increased energy expenditure (an increase in the CP(Res)-CG movements). These postural behavior alterations can be explained by various factors including a loss of muscle strength, residual apprehension due to the disuse of this limb, and persistent pain, all of which are increased by limb loading. These features should be taken into consideration when elaborating the rehabilitation protocol for these patients.

Survivorship of 2000 tapered titanium porous plasma-sprayed femoral components

Tapered titanium porous plasma-sprayed components have performed well in primary THA. To confirm the literature at longer followup we retrospectively reviewed all 1639 patients who underwent 2000 THAs in which a specific porous femoral component was used. One hundred fourteen patients (134 hips) were lost to followup leaving a cohort of 1525 patients (1866 THAs). The component is a tapered titanium plasma spray-coated design that remained relatively unchanged since its first implantation except for circumferential proximal porous coating added in 1986 and an offset option added in 1999. Minimum followup was 24 months (average, 119 months; range, 24 to 275 months). To date there have been 39 femoral revisions for an implant survival of 98%. Using the Kaplan-Meier method, cumulative survival with any stem revision as the end point was 98.6% at 5 years, 98.4% at 10 years, 97.1% at 15 years, and 95.5% at 20 years. Using aseptic revision for failure of ingrowth as the endpoint, stem survival was 99.1%. Kaplan-Meier cumulative survival with aseptic revision for failure of ingrowth as the endpoint was 99.4% at 5 years, 99.3% at 10, 15 and 20 years. Harris hip pain and total scores improved. This titanium, porous plasma spray-coated femoral component continues to demonstrate high long-term survival with a low rate of component revision for any reason or aseptic failure of ingrowth.

LEVEL OF EVIDENCE

Level IV, therapeutic study (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Progressive subsidence of a tapered, proximally coated femoral stem in total hip arthroplasty

The purpose of this study was to determine if subsidence of a tapered, proximally porous- and hydroxyapatite-coated femoral implant with immediate postoperative weight-bearing differed between men and women. Modified Harris Hip Pain and Function Scores were collected preoperatively, and six weeks and one year postoperatively. Femoral subsidence was determined at six weeks and one year after surgery. Men demonstrated significantly increased Harris Hip Function Scores at six weeks, with slightly inferior Harris Hip Pain Scores at one year. Regardless of sex, subsidence was greater at one year than at six weeks; however, men subsided significantly more at one year than women (1.7 +/- 2.0 mm vs 1.0 +/- 1.4 mm, p = 0.03). While it appears that this stem provided excellent early fixation in women, it is unclear if the increased subsidence in men was more related to patient-related factors of age, weight and activity level or with specific implant characteristics.

Hip arthroplasty with the thrust plate prosthesis in patients of 65 years of age or older: 67 patients followed 2-7 years

INTRODUCTION

Thrust plate prosthesis (TPP) is a relatively new concept in total hip arthroplasty and advocated to be used in young patients. We retrospectively evaluated the results of 67 patients (71 hips) who were older than 65 years of age and underwent hip arthroplasty using the TPP.

PATIENTS AND METHODS

There were 50 female and 17 male patients with a mean age 71 (range 65-89) years. All patients received accelerated rehabilitation program either with full weight bearing in the second postoperative day or at 6 weeks. All patients were followed-up for at least 2 years (range 28-87 months).

RESULTS

The average Harris hip score improved from 43 (range 8-72) to 93 (range 64-100) at the latest follow-up (p < 0.001). The overall revision rate was 8.4%. However, when the patients with definitive history of trauma were excluded the rate for loosening and technical errors decreased to 4.2%. There was no significant difference between the Harris hip score of patients with full weight bearing in the second postoperative day or 6 weeks (p = 0.57).

CONCLUSION

We conclude that the TPP could be indicated for older patients without age limit and that an accelerated rehabilitation program with early weight bearing can be applied to these patients.

Immediate weight bearing after cementless total hip arthroplasty

This study analyzed 399 Balance femoral stems to determine whether immediate full weight bearing following total hip arthroplasty affected radiographic osseointegration. Postoperatively, all patients were permitted unlimited weight bearing. Findings demonstrated osseointegration was successful in 99.5% of femoral components. Of these, 0.5% subsided in the first 6 postoperative weeks and then osseointegrated; 0.5% failed to osseointegrate. Patients with Dorr C bone had a significantly increased rate of subsidence (P=.006). These findings indicate the Balance stem reliably osseointegrates without subsidence in patients with Dorr A or B bone, despite immediate full weight bearing.

Immediate weight bearing after uncemented total hip arthroplasty with an anteverted stem: a prospective randomized comparison using radiostereometry

BACKGROUND

In uncemented total hip arthroplasty with hydroxyapatite coating, early weight bearing is frequently practiced but there is still not much evidence to support this recommendation.

METHOD

In a prospective randomized study we evaluated the effect of partial and full weight bearing after cementless total hip arthroplasty (ABG; Stryker-Howmedica) using radiostereometric analysis (RSA). Between February 1996 and February 2000, 43 consecutive patients (mean age 53 (41-63) years, 23 women) with hip osteoarthrosis received an uncemented and hydroxyapatite-coated prosthesis with an anteverted stem. All patients were operated in a standardized way by three experienced surgeons and they were randomized to partial (P) or full (F) weight bearing during the first 6 weeks after surgery. The patients in the partial weight bearing group were equipped with a pressuresensitive insole signaling when their load exceeded the prescribed weight limit.

RESULTS

At 3-month follow-up, the mean proximal (+)/ distal (-) migration of the stem was -0.14 mm (-1.93- 0.11) in group P and -0.31 mm (-4.30-0.16) in group F (p=0.6). At 1-year follow-up, the mean migration was -0.17 mm (-2.18-0.21) and -0.28 mm (-4.31-0.11), respectively (p=0.9). There was no significant difference in stem rotations either (p<0.2). The cup translations, rotations, and femoral head penetration were similar in the two groups (p<0.1). There were no re-operations during the first year.

INTERPRETATION

We did not find any adverse effect of full weight bearing immediately after operation, which justifies use of this regimen after uncemented total hip arthroplasty of the ABG type.

Simultaneous vs staged cementless bilateral total hip arthroplasty: perioperative risk comparison

Simultaneous vs staged bilateral total hip arthroplasty (THA) continues to evoke controversy, with perioperative complications representing the most significant issue. Previous authors have reported significant cost savings by performing bilateral THA simultaneously, but have failed to address issues of surgeon and hospital reimbursement. This study compares 277 consecutive patients undergoing either simultaneous (334 THAs) or staged bilateral cementless THA (220 THAs) in lateral decubitus position using a single cementless stem design, with emphasis on perioperative complications and reimbursement to surgeon and hospital. There were significantly more inpatient complications and adverse events in patients undergoing simultaneous bilateral THA in the lateral decubitus position, significantly higher transfusion requirement, and more patients failing to reach physical therapy goals during admission requiring more transfers to rehabilitation facilities. Need for subsequent hip surgery was also significantly higher in simultaneous bilateral patients. In addition to these negative results, the hospital system realized a 28% reduction and the surgeon suffered a 15% reduction in potential reimbursement.

Early migration pattern of the uncemented CLS stem in total hip arthroplasties

We performed this investigation to determine the possible migration starting immediately after surgery and the effect of different weightbearing regimens on the migration pattern of an uncemented hip stem (CLS). Stem migration was determined with radiostereometry analysis with baseline when the patients still were anesthetized. Subsequent examinations were done up to 1 year. Twenty-nine patients (mean age, 55 years; range, 26-63 years) were randomized to either unrestricted weightbearing combined with intensive physiotherapy from the first day after surgery or to partial weightbearing and a conservative training regimen for the first 3 months after surgery. At 1 week, subsidence was -0.03 mm in the unrestricted weightbearing group and 0.01 mm in the partial weightbearing group. At 1 year, subsidence was 1.01 mm in the unrestricted weightbearing group and 0.51 mm in the partial weightbearing group. One patient in the unrestricted weightbearing group had revision surgery because of aseptic loosening at 1.5 years after surgery. The CLS stem did not have any migration from the end the surgery until 1 week, but there was small migration from 1 week to 3 months after which the stem remained stable. The degree of early weightbearing did not affect the migration pattern.

Failure of the uncoated titanium ProxiLock femoral hip prosthesis

New prostheses should be evaluated for stability and clinical performance. In a prospective randomized clinical trial, we implanted 22 titanium (Ti) and 20 hydroxyapatite-coated (HA) ProxiLock femoral hip prostheses during total hip arthroplasty in 42 patients. The patients were followed for 24 months with clinical, radiographic and radiostereometric analysis. Full weightbearing was allowed immediately postoperatively. One patient with a titanium stem was lost to followup. During the first two months, 34 of the 41 stems subsided and/or rotated towards retroversion, regardless of stem type. At the 24-month followup 35 of the 41 prostheses were either fully stabilized (16 HA and 11 Ti stems) or had clinical irrelevant migration (four HA and four Ti stems). Six Ti prostheses showed continuous migrations with maximums of 4.7 mm translation and 12.2 degrees retroversion; four of these were revised, the other two had no clinical complaints.

CLINICAL RELEVANCE

The migration pattern we found indicates insufficient primary fixation of the ProxiLock stem in an immediate full weightbearing protocol. The HA coating improves the secondary stability of the prosthesis compared to the uncoated stem. Early migration is associated with an increased risk of possible future loosening and revision, and therefore we discontinued the use of this prosthesis.

LEVEL OF EVIDENCE

Therapeutic Level I. See Guidelines for Authors for a complete description of levels of evidence.

Yoke collar autograft: a technique for improving calcar contact in collared uncemented primary total hip arthroplasty

Yoke collar autograft is a successful means of achieving calcar-collar contact in cementless collared total hip arthroplasty.

Implant migration after early weightbearing in cementless hip replacement

Twenty-nine patients (five women and 24 men) with an average age of 47 years (range, 24-59 years) had 37 total hip arthroplasties using a hydroxyapatite-coated double-wedge press-fit femoral component. All patients had a Type A bone quality. Patients were either mobilized with weightbearing as tolerated or toe-touch weightbearing for 6 weeks postoperatively. After 6 weeks all patients were advanced to weightbearing as tolerated. Radiostereometric analysis radiographs were taken at 3 days, 6 weeks, and 6 months postoperatively to measure migration of the femoral component. Radiostereometric analysis revealed no difference in stem migration between the two groups as defined by maximal total point migration. There was a difference in the vertical (proximal-distal) migration within the first 6 weeks between groups (0.81 mm versus 0.13 mm), but not afterwards (0.17 mm versus 0.18 mm). Continuous migration after 6 weeks was observed in three patients from each group. There was no loosening in either group within a 2-year followup. Weightbearing as tolerated is recommended for young patients with excellent bone quality after cementless total hip arthroplasty with a double-wedge press-fit femoral component.

LEVEL OF EVIDENCE

Diagnostic study, Level I (testing of previously developed diagnostic criteria in series of consecutive patients--with previously applied reference gold standard). See the Guidelines for Authors for a complete description of levels of evidence.

Rapid rehabilitation and recovery with minimally invasive total hip arthroplasty

To assess the potential recovery rate of a minimally invasive total hip replacement technique with minimal soft tissue disruption, an accelerated rehabilitation protocol was implemented with weightbearing as tolerated on the day of surgery. One hundred consecutive patients were enrolled in this prospective study. Ninety-seven patients (97%) met all the inpatient physical therapy goals required for discharge to home on the day of surgery; 100% of patients achieved these goals within 23 hours of surgery. Outpatient therapy was initiated in 9% of patients immediately, 62% of patients by 1 week, and all patients by 2 weeks. The mean time to discontinued use of crutches, discontinued use of narcotic pain medications, and resumed driving was 6 days postoperatively. The mean time to return to work was 8 days, discontinued use of any assistive device was 9 days, and resumption of all activities of daily living was 10 days. The mean time to walk (1/2) mile was 16 days. Furthermore, there were no readmissions, no dislocations, and no reoperations. Therefore, a rapid rehabilitation protocol is safe and fulfills the potential benefits of a rapid recovery with minimally invasive total hip arthroplasty.

Direct two-incision total hip replacement without fluoroscopy

A new direct anatomic two-incision approach for total hip replacement without the use of fluoroscopy is described. The anterior incision is the distal one third of a Smith-Peterson approach and the posterior incision is the proximal one third of the Moore approach. It has been used on 142 unselected consecutive.

How accurate is partial weightbearing?

The accuracy of partial weightbearing was assessed in six healthy volunteers and 23 patients who had sustained either a fracture of a lower limb or surgery. They were trained to weightbear partially using the conventional bathroom scale method and were assessed in a gait laboratory using force platforms. The amount of weight exerted on the involved limb during three-point crutch walking was determined. Four of six volunteers exerted a mean of 27% of body weight more than required. The remaining two volunteers exerted a mean of 8.5% of body weight less than required. Of the 23 patients, 21 exerted a mean of 35.3% of body weight more than that prescribed and two patients exerted a mean of 11.97% of body weight less than that prescribed. In both groups there was little relationship between the weightbearing prescribed and actual weightbearing. None of the patients or volunteers was able to reproduce the extent of partial weightbearing for which they were trained using the bathroom scale method, confirming that this technique of instructing patients in partial weightbearing is inaccurate.

Comparison of two different rehabilitation programmes for thrust plate prosthesis: a randomized controlled study

OBJECTIVE

Weight bearing after total hip arthroplasty is postponed in order to prevent early loosening, but this negatively affects the rehabilitation programme. For the force transfer characteristics of thrust plate prosthesis (TPP), a new type of hip prosthesis used without cement is similar to the normal hip. We evaluated the possibilities of early weight bearing after TPP by comparing early partial with early full weight bearing.

DESIGN

Randomized controlled study.

SETTING

Department of orthopaedics and traumatology in a university hospital.

SUBJECTS

Sixty hips of 51 patients who underwent total hip arthroplasty with TPP were randomly assigned into two groups.

INTERVENTIONS

Both groups received accelerated rehabilitation programmes: group 1 with early partial weight bearing and group 2 with early full weight bearing.

MAIN OUTCOME MEASURES

Patients were evaluated by a blind observer preoperatively, at three months after surgery by clinical (measurement of range of hip motion (universal goniometry), muscle strength (Manual Muscle Test), functional test (6-minute walk test), hip function (Harris Hip Scoring System)) and radiographical parameters and one year after surgery by clinical (Harris Hip Scoring System) and radiographical parameters.

RESULTS

Group 2 performed transfer activities earlier, had more walking distance at the time of discharge and shorter hospital stay than group 1. At three months, Harris Hip Score, muscle strength, 6-minute walk test, and duration of crutch use were significantly (p < 0.05) in favour of group 2. None of the patients in either group showed signs of loosening one year after the operation.

CONCLUSIONS

These results suggest that patients with TPP can tolerate an accelerated rehabilitation programme with early weight bearing and will gain the goals of rehabilitation earlier.

The effect of partial or full weight bearing ambulation after cementless total hip arthroplasty

The clinical and radiographic results of 46 patients who underwent 50 consecutive primary total hip arthroplasties using a fully porous-coated collared femoral component were determined at a minimum of 2 years' follow-up. Twenty-four patients (25 hips) who were allowed to bear full weight immediately postoperatively were compared with a historical control group of 24 patients (25 hips) who were instructed to bear < or =50 lb of weight for 6 weeks. The average Harris hip score for the partial weight bearing group was 95 compared with 97 for the full weight bearing group. All femoral components in both groups had radiographic evidence of bone ingrowth fixation at the final follow-up. When solid initial fixation is obtained intraoperatively and radiographically using a fully porous-coated (AML) femoral component, it seems that bone ingrowth fixation reliably occurs whether or not a partial or full weight-bearing postoperative protocol is followed.

Total hip arthroplasty using two different cementless tapered stems

The authors report their 15-year experience with primary total hip arthroplasty using collarless, tapered, porous-coated femoral stems (Trilock and Taperloc) in patients with osteoarthritis, rheumatoid arthritis, and in octogenarians. Excellent clinical results were achieved in all groups at latest followup. For the patients with Trilock stems, Taperloc stems, and patients who were octogenarians and patients with rheumatoid arthritis, Charnley pain scores were 5.6, 5.5, 5.7, and 5.7; Charnley function scores were 5.2, 5.1, 4.2, and 5.3; Harris hip scores were 92, 92, 82, and 93 points, respectively. There was a 2% rate of thigh pain with the Trilock, 4% with Taperloc, 4% in octogenarians, and 2% in patients with rheumatoid arthritis. In 96% of the patients in the Trilock group, in 100% of the patients in the Taperloc group, in 100% of the patients who were octogenarians, and in 100% of the patients with rheumatoid arthritis, femoral components showed radiographic evidence of bone ingrowth. There were six (12%) femoral component revisions in the Trilock group (all secondary to nonmodularity of the component at the time of acetabular revision), one femoral component revision in the Taperloc group and no femoral component revisions in the patients who were octogenarians or who had rheumatoid arthritis. Design features (collarless tapered wedge fit, circumferentially porous-coated) virtually ensure bone ingrowth and are thought to be responsible for the excellent clinical results and longevity.

Immediate or late weight bearing after uncemented total hip arthroplasty: a study of functional recovery

Late weight bearing on the operated leg after uncemented total hip arthroplasty may slow the patient's rehabilitation. The aim of this study was to find out whether 12 weeks of non-weight-bearing gait had any influence on passive hip extension, muscle strength, gait velocity, pain, and walking pattern during the first 24 postoperative weeks. There were no significant differences in results 24 weeks after surgery between 10 patients with late weight bearing and 11 patients with immediate weight bearing. As expected, however, there was a difference in muscle strength between the operated and the nonoperated leg. This study shows no evidence that late weight bearing after uncemented total hip arthroplasty implies any serious adverse effects on functional recovery after 24 weeks compared with immediate postoperative weight bearing.

Late deep venous thrombosis and delayed weightbearing after total hip arthroplasty

One hundred ninety-nine patients who underwent primary total hip arthroplasty and used in hospital pneumatic compression stockings and aspirin as thromboembolic prophylaxis were screened for deep venous thrombosis using duplex ultrasonography on the fourth postoperative day. Of the initial 98 patients, 21 underwent noncemented arthroplasty, maintained touchdown weightbearing for 6 weeks after surgery, and then began progressive partial weightbearing. Of the subsequent 101 patients, 28 underwent noncemented arthroplasty and began progressive weightbearing immediately after surgery. All other patients underwent hybrid arthroplasty and began weightbearing to tolerance immediately after surgery. After duplex screening examination, patients with proximal deep venous thrombosis were given anticoagulation therapy, and patients with negative study results were observed clinically. The relative risk of proximal deep venous thrombosis after noncemented arthroplasty using delayed weightbearing was compared with that after noncemented arthroplasty using immediate progressive weightbearing. Of patients with noncemented arthroplasty, the prevalence of proximal deep venous thrombosis was significantly lower in those using progressive weightbearing immediately after surgery (none) than in those using delayed weightbearing rehabilitation (19%). This study showed that patients undergoing noncemented total hip arthroplasty with delayed weightbearing rehabilitation risk greater potential for deep venous thrombosis after hospital discharge. This study suggests consideration for continued thromboembolic prophylaxis or routine deep venous thrombosis surveillance, or both measures, after hospital discharge, unless more rapid progression of weightbearing is allowed.