The operation of the century: total hip replacement

In the 1960s, total hip replacement revolutionised management of elderly patients crippled with arthritis, with very good long-term results. Today, young patients present for hip-replacement surgery hoping to restore their quality of life, which typically includes physically demanding activities. Advances in bioengineering technology have driven development of hip prostheses. Both cemented and uncemented hips can provide durable fixation. Better materials and design have allowed use of large-bore bearings, which provide an increased range of motion with enhanced stability and very low wear. Minimally invasive surgery limits soft-tissue damage and facilitates accelerated discharge and rehabilitation. Short-term objectives must not compromise long-term performance. Computer-assisted surgery will contribute to reproducible and accurate placement of implants. Universal economic constraints in healthcare services dictate that further developments in total hip replacement will be governed by their cost-effectiveness.

Hip disability and osteoarthritis outcome score (HOOS)--validity and responsiveness in total hip replacement

BACKGROUND

The aim of the study was to evaluate if physical functions usually associated with a younger population were of importance for an older population, and to construct an outcome measure for hip osteoarthritis with improved responsiveness compared to the Western Ontario McMaster osteoarthritis score (WOMAC LK 3.0).

METHODS

A 40 item questionnaire (hip disability and osteoarthritis outcome score, HOOS) was constructed to assess patient-relevant outcomes in five separate subscales (pain, symptoms, activity of daily living, sport and recreation function and hip related quality of life). The HOOS contains all WOMAC LK 3.0 questions in unchanged form. The HOOS was distributed to 90 patients with primary hip osteoarthritis (mean age 71.5, range 49-85, 41 females) assigned for total hip replacement for osteoarthritis preoperatively and at six months follow-up.

RESULTS

The HOOS met set criteria of validity and responsiveness. It was more responsive than WOMAC regarding the subscales pain (SRM 2.11 vs. 1.83) and other symptoms (SRM 1.83 vs. 1.28). The responsiveness (SRM) for the two added subscales sport and recreation and quality of life were 1.29 and 1.65, respectively. Patients <or= 66 years of age (range 49-66) reported higher responsiveness in all five subscales than patients >66 years of age (range 67-85) (Pain SRM 2.60 vs. 1.97, other symptoms SRM 3.0 vs. 1.60, activity of daily living SRM 2.51 vs. 1.52, sport and recreation function SRM 1.53 vs. 1.21 and hip related quality of life SRM 1.95 vs. 1.57).

CONCLUSION

The HOOS 2.0 appears to be useful for the evaluation of patient-relevant outcome after THR and is more responsive than the WOMAC LK 3.0. The added subscales sport and recreation function and hip related quality of life were highly responsive for this group of patients, with the responsiveness being highest for those younger than 66.

Metal-on-metal resurfacing of the hip in patients under the age of 55 years with osteoarthritis

The results of conventional hip replacement in young patients with osteoarthritis have not been encouraging even with improvements in the techniques of fixation and in the bearing surfaces. Modern metal-on-metal hip resurfacing was introduced as a less invasive method of joint reconstruction for this particular group.

This is a series of 446 hip resurfacings (384 patients) performed by one of the authors (DJWM) using cemented femoral components and hydroxyapatite-coated uncemented acetabular components with a maximum follow-up of 8.2 years (mean 3.3). Their survival rate, Oxford hip scores and activity levels are reviewed.

Six patients died due to unrelated causes. There was one revision (0.02%) out of 440 hips. The mean Oxford score of the surviving 439 hips is 13.5. None of the patients were told to change their activities at work or leisure; 31% of the men with unilateral resurfacings and 28% with bilateral resurfacings were involved in jobs that they considered heavy or moderately heavy; 92% of men with unilateral hip resurfacings and 87% of the whole group participate in leisure-time sporting activity.

The extremely low rate of failure in spite of the resumption of high level occupational and leisure activities provides early evidence of the suitability of this procedure for young and active patients with arthritis.

Effect of acetabular component orientation on recurrent dislocation, pelvic osteolysis, polyethylene wear, and component migration

We retrospectively reviewed 75 total hip arthroplasties to examine the effect of acetabular component position. In group A, 38 of the components were implanted according to manufacture's instructions with all peripheral fins in contact with acetabular bone; as such, the acetabular components were in a relatively vertical position with a mean angle of inclination of 61.9 degrees. Three of these patients developed recurrent dislocations necessitating revision of the acetabular component. In group B, 37 hips, a more horizontal orientation was used despite the fact that all of the peripheral fins of the acetabular component did not engage acetabular bone; in this group the mean angle of inclination was 49.7 degrees. Only one of these hips recurrently dislocated and required revision. There were no problems in this group associated with provisional component stability caused by inadequate peripheral fixation. Radiographs of all patients were obtained at 4 years after surgery (range, 4.0-4.3 years). Pelvic osteolysis had occurred in 24% of hips in group A and 13% of group B. Asymmetric polyethylene wear was observed in 5.1% of the hips in group A; no hip in group B showed wear asymmetry. Acetabular component migration developed in 19% of group A hips and 5% of group B hips. The Mayo clinical hip score was excellent in both groups: group A 71/80, group B 73/80. At an intermediate follow-up it is clear that significant problems can be encountered when this component is positioned in a relatively vertical position to facilitate engaging all four peripheral fins in bone. We have addressed this problem by placing the cup in a more anatomic position of inclination while maintaining provisional rim fixation. This has resulted in a decreased incidence of pelvic osteolysis and fewer complications overall.

Development of an extremely wear-resistant ultra high molecular weight polyethylene for total hip replacements

Osteolysis induced by ultra high molecular weight polyethylene wear debris is one of the primary factors limiting the lifespan of total hip replacements. Crosslinking polyethylene is known to improve its wear resistance in certain industrial applications, and crosslinked polyethylene acetabular cups have shown improved wear resistance in two clinical studies. In the present study, crosslinked polyethylene cups were produced by two methods. Chemically crosslinked cups were produced by mixing a peroxide with ultra high molecular weight polyethylene powder and then molding the cups directly to shape. Radiation-crosslinked cups were produced by exposing conventional extruded ultra high molecular weight polyethylene bar stock to gamma radiation at various doses from 3.3 to 100 Mrad (1 Mrad = 10 kGy), remelting the bars to extinguish residual free radicals (i.e., to minimize long-term oxidation), and then machining the cups by conventional techniques. In hip-joint simulator tests lasting as long as 5 million cycles, both types of cross-linked cups exhibited dramatically improved resistance to wear. Artificial aging of the cups by heating for 30 days in air at 80 degrees C induced oxidation of the chemically crosslinked cups. However, a chemically crosslinked cup that was aged 2.7 years at room temperature had very little oxidation. Thus, whether substantial oxidation of chemically crosslinked polyethylene would occur at body temperature remains unclear. The radiation-crosslinked remelted cups exhibited excellent resistance to oxidation. Because crosslinking can reduce the ultimate tensile strength, fatigue strength, and elongation to failure of ultra high molecular weight polyethylene, the optimal crosslinking dose provides a balance between these physical properties and the wear resistance of the implant and might substantially reduce the incidence of wear-induced osteolysis with total hip replacements.

Single-incision anterior approach for total hip arthroplasty on an orthopaedic table

Dislocation remains the leading early complication of total hip arthroplasty; surgical approach and implant positioning have been recognized as factors influencing total hip arthroplasty stability. We describe a total hip arthroplasty technique done through a single, tissue sparing anterior approach that allows implantation of the femoral and acetabular components without detaching or sectioning any of the muscles and tendons around the hip joint. A series of 437 consecutive, unselected patients who had 494 primary total hip arthroplasty surgeries done through an anterior approach on an orthopaedic table from September 1996 to September 2004 was reviewed. There were 54 hybrid and 442 uncemented hips in the 437 patients (57 bilateral). The average patient age was 64 years. Radiographic analysis showed an average abduction angle of 42 degrees , with 96% in the range of 35 degrees to 50 degrees abduction. The average cup anteversion was 19 degrees with 93% within the target range of 10 degrees to 25 degrees . Postoperative leg length discrepancy averaged 3 +/- 2 mm (range, 0-26 mm). Three patients sustained dislocations for an overall dislocation rate of 0.61%, and no patients required revision surgery for recurrent dislocation. There were 17 operative complications, including one deep infection, three wound infections, one transient femoral nerve palsy, three greater trochanter fracture, two femoral shaft fractures four calcar fractures, and three ankle fractures. Operative time averaged 75 minutes (range 40-150 minutes), and the average blood loss was 350 mL (range, 100-1300 mL). The mean hospital stay was 3 days (range, 1-17 days). The anterior approach on the orthopaedic table is a minimally invasive technique applicable to all primary hip patients. This technique allows accurate and reproducible component positioning and leg-length restoration and does not increase the rate of hip dislocation.

LEVEL OF EVIDENCE

Therapeutic study, Level IV-1 (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Reducing the risk of dislocation after total hip arthroplasty: the effect of orientation of the acetabular component

Malposition of the acetabular component is a risk factor for post-operative dislocation after total hip replacement (THR). We have investigated the influence of the orientation of the acetabular component on the probability of dislocation. Radiological anteversion and abduction of the component of 127 hips which dislocated post-operatively were measured by Einzel-Bild-Röentgen-Analysis and compared with those in a control group of 342 patients. In the control group, the mean value of anteversion was 15 degrees and of abduction 44 degrees. Patients with anterior dislocation after primary THR showed significant differences in the mean angle of anteversion (17 degrees), and abduction (48 degrees) as did patients with posterior dislocation (anteversion 11 degrees, abduction 42 degrees). After revision patients with posterior dislocation showed significant differences in anteversion (12 degrees) and abduction (40 degrees). Our results demonstrate the importance of accurate positioning of the acetabular component in order to reduce the frequency of subsequent dislocations. Radiological anteversion of 15 degrees and abduction of 45 degrees are the lowest at-risk values for dislocation.

Hip arthroplasty

Total hip arthroplasty is a cost-effective surgical procedure undertaken to relieve pain and restore function to the arthritic hip joint. More than 1 million arthroplasties are done every year worldwide, and this number is projected to double within the next two decades. Symptomatic osteoarthritis is the indication for surgery in more than 90% of patients, and its incidence is increasing because of an ageing population and the obesity epidemic. Excellent functional outcomes are reported; however, careful patient selection is needed to achieve best possible results. The present economic situation in many developed countries will place increased pressure on containment of costs. Future demand for hip arthroplasty, especially in patients younger than 65 years, emphasises the need for objective outcome measures and joint registries that can track lifetime implant survivorship. New generations of bearing surfaces such as metal-on-metal, ceramic-on-ceramic, and metal-on-ceramic, and techniques such as resurfacing arthroplasty have the potential to improve outcomes and survivorship, but findings from prospective trials are needed to show efficacy. With the recall of some metal-on-metal bearings, new bearing surfaces have to be monitored carefully before they can be assumed to be better than traditional bearings.

Consensus statement for perioperative care in total hip replacement and total knee replacement surgery: Enhanced Recovery After Surgery (ERAS®) Society recommendations

Background and purpose - There is a large volume of heterogeneous studies across all Enhanced Recovery After Surgery (ERAS®) components within total hip and total knee replacement surgery. This multidisciplinary consensus review summarizes the literature, and proposes recommendations for the perioperative care of patients undergoing total hip replacement and total knee replacement with an ERAS program.Methods - Studies were selected with particular attention being paid to meta-analyses, randomized controlled trials, and large prospective cohort studies that evaluated the efficacy of individual items of the perioperative treatment pathway to expedite the achievement of discharge criteria. A consensus recommendation was reached by the group after critical appraisal of the literature.Results - This consensus statement includes 17 topic areas. Best practice includes optimizing preoperative patient education, anesthetic technique, and transfusion strategy, in combination with an opioid-sparing multimodal analgesic approach and early mobilization. There is insufficient evidence to recommend that one surgical technique (type of approach, use of a minimally invasive technique, prosthesis choice, or use of computer-assisted surgery) over another will independently effect achievement of discharge criteria.Interpretation - Based on the evidence available for each element of perioperative care pathways, the ERAS® Society presents a comprehensive consensus review, for the perioperative care of patients undergoing total hip replacement and total knee replacement surgery within an ERAS® program. This unified protocol should now be further evaluated in order to refine the protocol and verify the strength of these recommendations.

Birmingham hip resurfacing arthroplasty

We report the survival at five years of 144 consecutive metal-on-metal resurfacings of the hip implanted between August 1997 and May 1998. Failure was defined as revision of either the acetabular or femoral component for any reason during the study period. The survival at the end of five years was 98% overall and 99% for aseptic revisions only. The mean age of the patients at implantation was 52.1 years.

Three femoral components failed during the first two years, two were infected and one fractured. A single stage revision was carried out in each case. No other revisions were performed or are impending. No patients were lost to follow-up. Four died from unrelated causes during the study period.

This study confirms that hip resurfacing using a metal-on-metal bearing of known provenance can provide a solution in the medium term for the younger more active adult who requires surgical intervention for hip disease.

Tranexamic acid use and postoperative outcomes in patients undergoing total hip or knee arthroplasty in the United States: retrospective analysis of effectiveness and safety

OBJECTIVE

To determine the effectiveness and safety of perioperative tranexamic acid use in patients undergoing total hip or knee arthroplasty in the United States.

DESIGN

Retrospective cohort study; multilevel multivariable logistic regression models measured the association between tranexamic acid use in the perioperative period and outcomes.

SETTING

510 US hospitals from the claims based Premier Perspective database for 2006-12.

PARTICIPANTS

872,416 patients who had total hip or knee arthroplasty.

INTERVENTION

Perioperative intravenous tranexamic acid use by dose categories (none, ≤ 1000 mg, 2000 mg, and ≥ 3000 mg).

MAIN OUTCOME MEASURES

Allogeneic or autologous transfusion, thromboembolic complications (pulmonary embolism, deep venous thrombosis), acute renal failure, and combined complications (thromboembolic complications, acute renal failure, cerebrovascular events, myocardial infarction, in-hospital mortality).

RESULTS

While comparable regarding average age and comorbidity index, patients receiving tranexamic acid (versus those who did not) showed lower rates of allogeneic or autologous transfusion (7.7% v 20.1%), thromboembolic complications (0.6% v 0.8%), acute renal failure (1.2% v 1.6%), and combined complications (1.9% v 2.6%); all P<0.01. In the multilevel models, tranexamic acid dose categories (versus no tranexamic acid use) were associated with significantly (P<0.001) decreased odds for allogeneic or autologous blood transfusions (odds ratio 0.31 to 0.38 by dose category) and no significantly increased risk for complications: thromboembolic complications (odds ratio 0.85 to 1.02), acute renal failure (0.70 to 1.11), and combined complications (0.75 to 0.98).

CONCLUSIONS

Tranexamic acid was effective in reducing the need for blood transfusions while not increasing the risk of complications, including thromboembolic events and renal failure. Thus our data provide incremental evidence of the potential effectiveness and safety of tranexamic acid in patients requiring orthopedic surgery.

Infection of the surgical site after arthroplasty of the hip

We wished to estimate the incidence of surgical-site infection (SSI) after total hip replacement (THR) and hemiarthroplasty and its strength of association with major risk factors. The SSI surveillance service prospectively gathered clinical, operative and infection data on inpatients from 102 hospitals in England during a four-year period. The overall incidence of SSI was 2.23% for 16,291 THRs, 4.97% for 5769 hemiarthroplasty procedures, 3.68% for 2550 revision THRs and 7.6% for 198 revision hemiarthroplasties. Staphylococcus aureus was identified in 50% of SSIs; 59% of these isolates were methicillin-resistant (MRSA). In the single variable analysis of THRs, age, female gender, American Society of Anesthesiologists (ASA) score, body mass index, trauma, duration of operation and pre-operative stay were significantly associated with the risk of SSI (p < 0.05). For hemiarthroplasty, the ASA score and age were significant factors. In revision THRs male gender, ASA score, trauma, wound class, duration of operation and pre-operative stay were significant risk factors. The median time to detection of SSI was eight days for superficial incisional, 11 days for deep incisional and 11 days for joint/bone infections. For each procedure the mean length of stay doubled for patients with SSI. The multivariate analysis identified age group, trauma, duration of operation and ASA score as significant, independent risk factors for SSI. There was significant interhospital variation in the rates of SSI. MRSA was the most common pathogen to cause SSI in hip arthroplasty, especially in patients undergoing hemiarthroplasty, but coagulase-negative Staph. aureus may be more important in deep infections involving the joint.

Long-term registration has improved the quality of hip replacement: a review of the Swedish THR Register comparing 160,000 cases

The Swedish Hip Register has defined the epidemiology of total hip replacement in Sweden. Most hip implants are fully cemented. Serious complications and rates of revision have declined significantly despite an increasing number of patients at risk. During the past 5 years, only 8-9% of hip replacements are revisions. Aseptic loosening with or without osteolysis is the major problem and constitutes 71% of the revisions, but the incidence had decreased three times during the past 15 years to less than 3% at 10 years. The effectiveness of the surgical technique is the most important factor for reducing the risk of revision because of aseptic loosening, but choice of implant is also important. In practice, total hip replacement in Sweden has improved, as judged by information from this Register about individualized patient risks, implant safety, and the greater efficacy of surgical and cementing techniques.

Perioperative comparative effectiveness of anesthetic technique in orthopedic patients

BACKGROUND

The impact of anesthetic technique on perioperative outcomes remains controversial. We studied a large national sample of primary joint arthroplasty recipients and hypothesized that neuraxial anesthesia favorably influences perioperative outcomes.

METHODS

Data from approximately 400 hospitals between 2006 and 2010 were accessed. Patients who underwent primary hip or knee arthroplasty were identified and subgrouped by anesthesia technique: general, neuraxial, and combined neuraxial-general. Demographics, postoperative complications, 30-day mortality, length of stay, and patient cost were analyzed and compared. Multivariable analyses were conducted to identify the independent impact of choice of anesthetic on outcomes.

RESULTS

Of 528,495 entries of patients undergoing primary hip or knee arthroplasty, information on anesthesia type was available for 382,236 (71.4%) records. Eleven percent were performed under neuraxial, 14.2% under combined neuraxial-general, and 74.8% under general anesthesia. Average age and comorbidity burden differed modestly between groups. When neuraxial anesthesia was used, 30-day mortality was significantly lower (0.10, 0.10, and 0.18%; P < 0.001), as was the incidence of prolonged (>75th percentile) length of stay, increased cost, and in-hospital complications. In the multivariable regression, neuraxial anesthesia was associated with the most favorable complication risk profile. Thirty-day mortality remained significantly higher in the general compared with the neuraxial or neuraxial-general group for total knee arthroplasty (adjusted odds ratio [OR] of 1.83, 95% CI 1.08-3.1, P = 0.02; OR of 1.70, 95% CI 1.06-2.74, P = 0.02, respectively).

CONCLUSIONS

The utilization of neuraxial versus general anesthesia for primary joint arthroplasty is associated with superior perioperative outcomes. More research is needed to study potential mechanisms for these findings.

Surgical approach, abductor function, and total hip arthroplasty dislocation

Dislocation is a leading early complication of total hip arthroplasty. The effect of surgical approach on instability and abductor function is a controversial topic. A comprehensive literature review was done to evaluate the correlation of surgical approach and primary total hip arthroplasty dislocation. Two hundred sixty clinical studies were identified between 1970 and 2001. Four prospective studies were identified but individually they contained insufficient power or control groups to reach statistical significance regarding surgical approach and dislocation. Fourteen studies involving 13,203 primary total hip arthroplasties met the inclusion criteria based on variables previously shown to affect stability. These studies were evaluated with respect to surgical approach and dislocation. The combined dislocation rate for these studies was 1.27% for the transtrochanteric approach, 3.23% for the posterior approach (3.95% without posterior repair and 2.03% with posterior repair), 2.18% for the anterolateral approach, and 0.55% for the direct lateral approach. Eight studies involving 2455 primary total hip arthroplasties evaluated postoperative limp. The incidence of postoperative limp was 4% to 20% for patients who had the lateral approach and 0% to 16% for patients who had the posterior approach. The quality of the literature regarding surgical approach, dislocation rates, and abductor function is limited. Larger controlled prospective studies are needed to investigate the potential benefits of the posterior approach in lieu of a dislocation rate six times higher than the direct lateral approach for primary total hip arthroplasty.

Posterior approach to total hip replacement using enhanced posterior soft tissue repair

The two senior authors (PMP, RP) independently began using an identical enhanced posterior soft tissue repair after total hip replacement through a posterior approach. In the first author's experience, a dislocation rate of 4% in 395 patients before using the enhanced closure was reduced to 0% in 395 patients in whom the enhanced closure was performed. In the second author's experience, 160 total hip replacements had a dislocation rate of 6.2% before the enhanced closure whereas 124 total hip replacements had a dislocation rate of 0.8% after the enhanced closure. These results are highly statistically significant.

Operative management of displaced femoral neck fractures in elderly patients. An international survey

BACKGROUND

Hip fractures occur in 280,000 North Americans each year. Although surgeons have reached consensus with regard to the treatment of undisplaced fractures of the hip, the surgical treatment of displaced fractures remains controversial. Identifying surgeons' preferences in techniques, and the rationale for their choices, may aid in focusing educational activities to the orthopaedic community as well as planning future clinical trials. Our objective was to clarify current opinion with regard to the operative treatment of displaced fractures of the femoral neck.

METHODS

We used a cross-sectional survey design and a sample-to-redundancy strategy to examine surgeons' preferences in the treatment of displaced femoral neck fractures. We mailed this survey to members of the Orthopaedic Trauma Association and European-AO International-affiliated trauma centers.

RESULTS

Of 442 surgeons who received the questionnaire, 298 (67%) responded. The typical respondent was a North American man over the age of forty years who was in academic practice, supervised residents, had fellowship training in trauma, and worked in a low-volume center (<100 hip fractures per year), treating an equal proportion of displaced and undisplaced femoral neck fractures. Most surgeons believed that internal fixation was the procedure of choice in younger patients (those who are less than sixty years old) with a displaced fracture (Garden type III or IV). For patients over eighty years old with Garden type-III or IV fractures, almost all surgeons preferred arthroplasty. Respondents varied widely in their preferences for the treatment of patients who were sixty to eighty years old with a displaced fracture (Garden type III or IV) or active patients with a Garden type-III fracture. Many surgeons believed there was no difference between arthroplasty and internal fixation when considering mortality (45%), infection rates (30%), and quality of life (37%). Surgeons also revealed variable preferences in their choice of the optimal approach to arthroplasty for patients between sixty and eighty years old with a type-IV fracture (32% preferred unipolar; 41%, bipolar; and 17%, total hip arthroplasty) and in the optimal choice of implant for internal fixation.

CONCLUSIONS

While surgeons prefer internal fixation for younger patients and arthroplasty for older patients, they disagree about the optimal approach to the management of patients between sixty and eighty years old with a displaced fracture and active patients with a Garden type-III fracture. Surgeons also disagree on the optimal implants for internal fixation or arthroplasty.

A randomised controlled trial comparing bipolar hemiarthroplasty with total hip replacement for displaced intracapsular fractures of the femoral neck in elderly patients

The best treatment for the active and lucid elderly patient with a displaced intracapsular fracture of the femoral neck is still controversial. Randomised controlled trials have shown that a primary total hip replacement is superior to internal fixation as regards the need for secondary surgery, hip function and health-related quality of life. Despite good results achieved with total hip replacement in this group, most orthopaedic surgeons still advocate hemiarthroplasty for this injury. We studied 120 patients with a mean age of 81 years (70 to 90) with an acute displaced intracapsular fracture of the femoral neck. They were randomly allocated to be treated with either a bipolar hemiarthroplasty or total hip replacement. Outcome measurements included peri-operative data, general and hip-specific complications, hip function and health-related quality of life. The patients were reviewed at four and 12 months.

The duration of surgery was longer in the total hip replacement group (102 minutes (70 to 151)) versus 78 minutes (43 to 131) (p < 0.001), and the intra-operative blood loss was increased 460 ml (100 to 1100) versus 320 ml (50 to 850) (p < 0.001), but there were no differences between the groups regarding any complications or mortality. There were no dislocations in either group. Hip function measured by the Harris hip score was significantly better in the total hip replacement group at both follow-up periods (p = 0.011 and p < 0.001, respectively). The health-related quality of life measure was in favour of the total hip replacement group but did not reach statistical significance (p = 0.818 at four months and p = 0.636 at 12 months).

These results indicate that a total hip replacement provides better function than a bipolar hemiarthroplasty as soon as one year post-operatively, without increasing the complication rate. We recommend total hip replacement as the primary treatment for this group of patients.

A minimal-incision technique in total hip arthroplasty does not improve early postoperative outcomes. A prospective, randomized, controlled trial

BACKGROUND

Minimally invasive total hip arthroplasty has stirred substantial controversy with regard to whether it provides superior outcomes compared with total hip arthroplasty performed through longer incisions. The orthopaedic literature is deficient in well-designed scientific studies to support the clinical superiority of this approach. The objective of this study was to compare the results of a single mini-incision approach with those of a standard-incision total hip arthroplasty in the early postoperative period.

METHODS

Two hundred and nineteen patients (219 hips) admitted for unilateral total hip arthroplasty between December 2003 and June 2004 were randomized to undergo surgery through a short incision of <or=10 cm or a standard incision of 16 cm. All patients were blinded to the size of the incision for the duration of the hospital stay. The anesthetic, analgesic, and postoperative physiotherapy protocols were standardized, with the staff also blinded to the technique used. A single surgeon, who had performed more than 300 short-incision hip replacements prior to the start of this study and who performs an average of 415 primary total hip replacements a year, performed all procedures through a single-incision posterior approach using a cementless cup and cemented stem.

RESULTS

The two groups were matched for age, grade according to the system of the American Society of Anesthesiologists, and body mass index. No significant difference was detected with respect to postoperative hematocrit, blood transfusion requirements, pain scores, or analgesic use. We found no difference in early walking ability or length of hospital stay and no difference in component placement, cement-mantle quality, or functional outcome scores at six weeks. The patient variables significantly associated with a probability of early discharge independent of incision length were patient age and preoperative hemoglobin levels (p < 0.05). The surgical scars contracted significantly over six weeks (p < 0.05) but by a similar proportion of 11% to 12% in both groups.

CONCLUSIONS

Minimally invasive total hip arthroplasty performed through a single-incision posterior approach by a high-volume hip surgeon with extensive experience in less invasive approaches to the hip is safe and reproducible. However, it offers no significant benefit in the early postoperative period compared with a standard incision of 16 cm. As it is not known whether lower-volume and less-experienced surgeons can achieve similar results, the mini-incision technique merits further study before wide dissemination and implementation of this family of surgical approaches can be recommended.

Internal fixation versus hemiarthroplasty versus total hip arthroplasty for displaced subcapital fractures of femur--13 year results of a prospective randomised study

In this prospective randomised trial we compare the mortality, morbidity and functional results of patients following each of the three principal methods of treatment for displaced subcapital fractures of the femur. Two hundred and ninety patients over the age of 65 years were included and randomly allocated to undergo closed reduction and internal fixation with a sliding compression screw plate or uncemented Austin Moore hemiarthroplasty or cemented Howse II total hip arthroplasty (THA). Nineteen patients were subsequently excluded. The 13 year results show that there was no statistical difference in the mortality between the three groups (81, 85 and 91% respectively). Internal fixation and hemiarthroplasty groups fared poorly with a revision rate of 33 and 24%, respectively, compared with 6.75% in the THA group. The dislocation rate was 13% following hemiarthroplasty and 20% following THA. Average Harris hip scores were 62, 55 and 80, respectively, for the internal fixation, hemiarthroplasty and THA groups. In the long term, both internal fixation and hemiarthroplasty resulted in a poor outcome with respect to pain and mobility. Despite high early complications, THA resulted in least pain and most mobility both in the short and long-term and was encouraging with a revision rate of only 6.25%. THA should be seriously considered in physiologically active patients with a displaced subcapital fracture of the femur.

Squeaking in ceramic-on-ceramic hips: the importance of acetabular component orientation

Audible squeaking in total hip replacements with ceramic-on-ceramic bearings is a rare problem. Acetabular component orientation was compared for 17 squeaking hips and 17 matched controls. Ninety-four percent of control hips were in a range of 25 degrees +/- 10 degrees anteversion and 45 degrees +/- 10 degrees inclination, but only 35% of squeaking hips were in this range (P = .0003). Eight hips squeak with bending. Four hips squeak with walking, and 5 hips squeak after prolonged periods of walking. Hips that squeaked with walking had acetabular components that were more anteverted (40 degrees ) than hips that squeaked with bending (19 degrees ) (P = .001) or prolonged walking (18 degrees ) (P = .020). The hips started squeaking after an average of 14 months. Patients with squeaking hips were younger, heavier, and taller than patients with silent hips.

Minimum 10-year-results of extensively porous-coated stems in revision hip arthroplasty

Obtaining predictable, stable fixation of revision femoral implants is important for the long-term success of revision hip arthroplasty. The authors report on minimum 10 years clinical and radiographic followup of 170 patients with extensively coated cementless revision femoral components. With a range of followup of 10 to 16 years and a mean of 13.2 years, a survivorship of greater than 95% was reported. Clinically, the average Postel-D'Aubigne pain and walking score improved from a preoperative score of 5.4 points to 10.8 points postoperatively. Eighty-two percent of the hips had radiographic evidence of a bone-ingrown prosthesis and 13.9% had evidence of stable fibrous fixation. Four percent of stems were unstable as seen on radiographs. Six stems were revised to larger extensively coated stems and one stem is causing pain and is unstable but has yet to be revised. The overall mechanical failure rate was 4.1%. Stress shielding was greatest in patients with stems larger than 16.5 mm and in osteoporotic bone (Dorr Type C). Nine percent of patients had significant thigh pain including all of the patients with unstable stems. In the presence of bone loss in the proximal metaphyseal region of the femur, fixation of the femoral component is predictable when optimizing prosthetic-bone fit in the diaphyseal region of the femur using an extensively coated femoral component.