The effect of partial or full weight bearing ambulation after cementless 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.

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.

Complication Rates Following Total Ankle Arthroplasty in Inpatient versus Outpatient Populations: A Systematic Review & Meta-Analysis

Total ankle arthroplasty (TAA) is used as an alternative to ankle arthrodesis for adults with severe ankle arthritis. Numerous orthopedic centers have entered the healthcare market offering fast-tracked joint replacement protocols, meanwhile, TAA has been excluded from these joint centers, and is primarily performed in the inpatient setting. The purpose of this study is to examine short-term complications in the inpatient and outpatient settings following TAA using a systematic review and quantitative analysis. We considered all studies examining short-term complications following TAA performed in the inpatient versus outpatient setting occuring within 1 year of the index operation. We summarized data using a pooled relative risk and random effects model. A pooled sensitivity analysis was performed for studies with data on complication rates for inpatient or outpatient populations, which did not have a control group. The quality of included studies was assessed using the Cochrane risk of bias tool. Nine studies were included in the quantitative analysis, with 4 studies in the final meta-analysis. Subjects undergoing inpatient surgery experienced a 5-times higher risk of short-term complications compared to the outpatient group (risk ratio 5.27, 95% confidence interval 3.31, 8.42). Results did not change after sensitivity analysis (inpatient weighted mean complication rate: 9.62% vs outpatient weighted mean 5.02%, p value <.001). The overall level of evidence of included studies was level III, with a moderate to high risk of bias. Outpatient TAAs do not appear to pose excess complication risks compared to inpatient procedures, and may therefore be a reasonable addition to experienced centers that have established a fast-track outpatient total joint protocol.

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.

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).

Midterm results following uncemented, modular, fully porous coated stem used in revision total hip arthroplasty: Comparison of two stem systems

BACKGROUND

Aim of this study was to evaluate stem subsidence and survivorship of implant following implantation of Revitan (Zimmer) and MP (Waldemar Link) stems.

METHODS

Retrospective case series with clinical and radiological follow-up of 1-10 years.

RESULTS

47 Revitan and 57 MP stems were analyzed. In 12 cases there was subsidence of the stem present. Two Revitan stems and one MP stem were revised as a result of subsidence. Failure rate was 4.3% for Revitan, 1.8% for MP stem and difference was not statistically significant.

CONCLUSION

There is no significant difference in subsidence or survivorship between Revitan and MP stems.

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.

Task-oriented exercises and early full weight-bearing contribute to improving disability after total hip replacement: a randomized controlled trial

Objective:

To evaluate the efficacy of an in-hospital programme based on task-oriented exercises associated with early full weight-bearing in patients with multiple comorbidities undergoing total hip replacement.

Design:

Randomized controlled trial.

Setting:

Specialised rehabilitation centre.

Subjects:

A total of 100 patients (mean age of 69 (8) years; 40 males, 60 females).

Interventions:

The experimental group underwent task-oriented exercises and was encouraged to abandon any walking aids by the end of their in-hospital stay. The control group underwent open chain kinetic exercises, and was recommended to use partial weight-bearing and walking aids until three months after surgery. Both groups individually followed programmes of 90-minute sessions five times a week for three weeks.

Outcome measures:

Western Ontario and McMaster Universities Osteoarthritis Index, Pain Numerical Rating Scale, Functional Independence Measure, and Short-Form Health Survey. The participants were evaluated before, after training, and after a further 12 months.

Results:

There were no significant between-group differences at baseline. After training, a between-group difference of 12 points was found for the Western Ontario and McMaster Universities Osteoarthritis Index – functional subscale, indicating a clinically tangible treatment effect on disability. The Functional Independence Measure increased by 31 and 15 points in the experimental and control group, respectively. A linear mixed model revealed significant effects of time, group, and time by group interaction on disability, pain, activities of daily living, and most of the physical quality of life domains.

Conclusion:

Task-oriented exercises associated with early full weight-bearing improve disability, pain, activities of daily living, and quality of life after total hip replacement.

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.

Total hip arthroplasty for fractures of the proximal femur in older patients

Displaced fractures of the proximal femur are common in older patients. The optimal treatment is still under debate. We retrospectively reviewed the results of 53 consecutive total hip arthroplasties (THA) performed in 12 men and 41 women for treatment of an acute fracture of the proximal femur. Men had an average age of 75.1 years (range, 61 to 90) and women 78.2 years (range, 61 to 91). At time of fracture, 42 patients (79.3 %) had radiological signs of hip osteoarthritis. At time of surgery, 8 patients (15.1%) needed trochanteric reconstruction in addition to the implanted THA.Clinical and radiological follow-up was available for 39 patients (73.6 %). The average follow-up time was 55.5 months. The mean Harris Hip Score was 86.3 points (range, 68-97.7). The 4 month mortality rate was 1.9 % (1 patient). Four patients (7.5%) had had early postoperative complications, including dislocation in 3 patients (5.6%) and one (1.9%) minor reoperation (wound haematoma). One patient (1.9%) had revision surgery because of aseptic stem loosening 67 months after primary implantation. In elderly patients, THA is a safe long-term solution for treatment of displaced fractures of the proximal femur, allowing early weight bearing and assisting with rehabilitation.

Cementless total hip arthroplasty specifically designed for asians: clinical and radiologic results at a mean of 10 years

It is known that the proximal femoral osteometry is different between Asians and whites. An uncemented femoral stem was therefore designed by us specifically for Asians, and we now report the medium-term clinical results. Results of a proximally porous-coated femoral component anatomically matched for Asians were analyzed in a consecutive cohort of 48 hips. The mean follow-up was 10.3 years. The mean Harris hip score was 39.4 preoperatively and 94.2 at last follow-up (P < .001). All stems had bone ingrowth. Stem survival was 100% up to 14 years using revision as the end point. Eight acetabular component revisions were performed for bearing surface failures and osteolysis. This femoral stem, specifically designed for better fit in an Asian population, had excellent clinical and radiologic outcome.

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.

[Konzept Perioperative management for endoprosthetic hip joint replacement. The functional interdisciplinary therapy (FIT) concept]

During the last decade there have been significant changes in the perioperative management of total hip replacement patients. This process begins in the preoperative phase. Many patients are much better informed and standardized preoperative patient programs improve patient outcome and optimize the clinical pathways. The techniques in perioperative pain management have also significantly improved. The surgeon should not only rely on the anesthesiologist but should also use the options available during surgery. Postoperative weight bearing is handled in a much more progressive way than previously. In a standard primary hip replacement pain-adapted full weight bearing is possible if there are no patient-specific problems. There has also been a shift in the postoperative capability of performing athletic or recreational activities. In general patients can perform those activities that were performed before the surgery, which also includes, for example downhill skiing.

[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.

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.

The effect of early weight bearing on migration pattern of the uncemented CLS stem in total hip arthroplasty

Forty-two patients (younger than 65 years) with osteoarthritis were operated on with an uncemented CLS stem and randomized to early unrestricted weight bearing combined with intensive physiotherapy or to partial weight bearing combined with self-training. Radiostereometric analysis showed 1.2 (+0.11 to -6.76) mm subsidence of the stem at 24 months in both groups. There was no significant difference in the migration pattern between the unrestricted and partial weight bearing groups. Actual loading on the operated leg, measured with the F-scan system, did not influence the migration of the stem. There was a strong correlation between the average subsidence at 3 and 24 months (r = 0.96). Early full weight bearing and active rehabilitation can be used for the uncemented CLS stem without increased risk of early loosening.

Effect of robotic milling on periprosthetic bone remodeling

The ROBODOC system has provided better fit and fill of the stem and less destruction of the bony architecture than with manual surgery. These benefits might affect femoral periprosthetic bone remodeling. We evaluated the effects of robotic milling in cementless total hip arthroplasty (THA) in a longitudinal 24-month follow-up study using dual energy X-ray absorptiometry (DEXA) and plain radiographs of 29 patients (31 hips) after ROBODOC THA and 24 patients (27 hips) after manual THA with the same stem design. To minimize the influence of other factors on bone remodeling, only female osteoarthritis patients, who had no drugs that might affect bone metabolism were enrolled. Significantly less bone loss occurred at the proximal periprosthetic areas in the ROBODOC group. In zone 1, the decrease was 15.5 versus 29.9% using conventional rasping; in zone 7, the loss was 17.0% with ROBODOC compared to 30.5% with conventional rasping (p < 0.05). On radiographs, endosteal spot welds in the proximal medial portion were more pronounced in the ROBODOC group (48 vs. 11% in the conventional group, p < 0.05). Our results suggest that robotic milling is effective in facilitating proximal load transfer around the femoral component and minimizing bone loss after cementless THA.

A comparison of the results of total hip and knee arthroplasty performed on a teaching service or a private practice service

BACKGROUND

Active participation of residents and fellows in the performance of total hip and total knee arthroplasties may affect the outcomes of these procedures. We evaluated the early clinical results and complications associated with primary total hip and knee arthroplasties at a hospital that had both university teaching and private practice orthopaedic services.

METHODS

We performed a retrospective study on a consecutive series of 347 patients who had undergone 230 total hip and 171 total knee procedures performed by one attending surgeon. One hundred and sixty-nine patients underwent an arthroplasty during which a resident or fellow on a teaching service assisted the attending surgeon; during these procedures, the resident or fellow performed part of the arthroplasty under the direct supervision of the attending surgeon. Subsequently, 178 patients underwent an arthroplasty performed by the same surgeon without resident or fellow participation.

RESULTS

Significantly longer operative times were recorded for both total hip arthroplasty (average, seventy-three compared with sixty-one minutes; p < 0.0001) and total knee arthroplasty (average, eighty compared with seventy-three minutes; p = 0.0028) when the procedures were performed with the participation of residents or fellows. For total hip arthroplasty the complication rates were 8% for the teaching service and 10% for the private practice service, and for total knee arthroplasty they were 3% for each service. With the numbers studied, there were no differences in any clinical outcomes between the groups.

CONCLUSIONS

Teaching and active participation from residents and fellows during total hip and total knee arthroplasty did not have a detrimental effect on the early clinical results, except for a longer surgical time.

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.

Early outcomes following minimally invasive total hip arthroplasty using a two-incision approach versus a mini-posterior approach

We evaluated early clinical results and radiographic findings of MIS THA using 2-incsion approach and mini-posterior approach. A consecutive series of 35 patients (40 hips) with 2-incision THA and a consecutive series of 35 patients (36 hips) with mini-posterior THA performed in the same period were evaluated. The patient groups were not randomised. At the mean follow-up of 20.2 months (range, 12-36 months), the 2-incision group had significantly earlier ambulation, driving ability and return to work. However, it had significantly more operative time, blood loss, blood transfusion and complications. Regarding radiographic findings of 2-incision group and mini-posterior group, the mean radiographic acetabular abduction of was 46.7 degrees (89% was within 35- 55) and 44.8 degrees (84% was within 35-55), respectively. The femoral stem was in neutral position in 80% and 83%, respectively. There was no statistical difference of the implant position between groups. Although MIS 2-incison THA provided faster, early ambulation than the mini-posterior THA, surgeons have to weigh the advantages and disadvantages of this technique including, increased operative time, blood loss and their familiarity with similar standard incisions and landmarks.

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.

Comparison of primary total hip replacements performed with a standard incision or a mini-incision

BACKGROUND

Primary total hip replacement performed through an incision that is </=10 cm in length has been advocated as a minimally invasive technique. Proponents have claimed that mini-incision techniques reduce blood loss, transfusion requirements, postoperative pain, and the length of the hospital stay compared with standard techniques through a longer incision. However, we are aware of no well-designed comparison study that supports these claims. The purpose of the present study was to compare the short-term results of a mini-incision with a standard incision technique for total hip replacement.

METHODS

A consecutive series of patients who underwent 135 primary unilateral total hip replacements (fifty with use of a mini-incision [</=10 cm] and eighty-five with use of a standard incision) by three surgeons at one hospital were studied. Each surgeon selected patients to have a mini-incision procedure and performed a standard approach in the remaining patients. A posterior approach was used for all procedures. In-hospital data were collected retrospectively, and the initial postoperative radiographs were analyzed. Because of the selection process, the patients who had a mini-incision had both a significantly lower average body-mass index (p = 0.008) and a lower average score on the American Society of Anesthesiologists rating (p = 0.006), indicating that they were thinner and healthier than the patients who had a standard incision.

RESULTS

With the numbers of patients available, no significant differences were found between the groups with respect to the average surgical time, intraoperative blood loss, in-hospital transfusion rate, length of hospital stay, or the patients' disposition after discharge. The mini-incision group was found to have a significantly higher risk of a wound complication (p = 0.02), a higher percentage of acetabular component malposition (p = 0.04), and poor fit and fill of femoral components inserted without cement (p = 0.0036).

CONCLUSIONS

There was no evidence that the mini-incision technique resulted in less bleeding or less trauma to the soft tissues of the hip, factors that would have produced a quicker recovery and a shorter hospital stay, than did the standard technique. The present study, which was based on the authors' initial experience with the mini-incision technique, failed to confirm the positive clinical outcomes reported by previous uncontrolled cohort studies, and the findings suggest that further analysis of this new technique is needed before it can be recommended for general use.

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.