Impact of preoperative variables on the functional and radiological outcome of an uncemented femoral stem: a prospective two-year follow-up

Bone remodeling, around an anatomical hip stem: a one year prospective study using DEXA

INTRODUCTION

The loss of bone mass, as a consequence of bone remodelling, in the proximal third of the femur, is a factor that contributes to the failure of hip prostheses in the medium to long term. This periprosthetic remodelling occurs mainly during the first 12 months after the operation. The aim is to evaluate the behaviour at one year of a new anatomical stem, the ANATO® stem (2015-Stryker®), which is a redesign of its predecessor (ABG-ii®-Stryker stem) by means of bone densitometry.

METHOD

Prospective, controlled study in which the changes in bone mineral density (BMD) observed around the seven areas of Gruen in a group of 61 patients affected by primary coxarthrosis, in whom an ANATO® stem was implanted, are analysed densitometrically. The healthy hip was taken as the control group. The existence of differences in the remodelling pattern according to sex, age and body mass index (BMI) was compared. The follow-up was during the first year after the intervention.

RESULTS

After one year of follow-up, decreases of bone mineral density in zone seven of -5.9% were observed, being this decrease statistically significant. No differences were found in the remodelling pattern according to age, sex and body mass index.

CONCLUSION

The ANATO® stem allows an efficient transmission of loads from the stem to the proximal femur. Only in zone seven significant bone atrophy is observed. Differences in age, BMI and sex do not seem to influence the bone remodelling around this new stem.

No Difference in Outcomes 12 and 24 Months After Lower Extremity Total Joint Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

A better understanding of how patient-reported outcome measures (PROMs) change after total knee and hip arthroplasties (TKA and THA) is needed to support the minimum arbitrary follow-up of 24-months required by orthopedic journals. Therefore, our purpose was to perform a systematic review and meta-analysis of the THA and TKA literature to determine if equivalence exists between 12- and 24-month outcomes data.

METHODS

A search was performed using the PubMed and EMBASE databases for primary and revision THA and TKA studies reporting PROMs data at both 12 and 24 months. Reports on PROMs for TKA and THAs were included for meta-analysis to detect statistical differences at 12 and 24 months.

RESULTS

A total of 15 reports from 9 TKA (n = 1564) and 6 THA (n = 740) reports were analyzed. The mean change between 12 and 24 months for Knee Society Score was 0.15 absolute points (95% confidence interval [CI]: 0.97-1.06, P = .13) and for Western Ontario and McMaster Universities Osteoarthritis index was 0.50 absolute points (95% CI: 0.94-1.07, P = .49). The mean change between 12 and 24 months for Harris Hip Score was 2.01 absolute points (95% CI: 0.94-1.1, P = .22) and for short form was 0.02 absolute points (95% CI: 0.92-1.08, P = .94).

CONCLUSION

No different outcomes were found within THA and TKA for 4 PROMs at 12- and 24-month follow-up. Although the findings from this study do not alleviate the need for collecting data from longer follow-up periods, there may not be additional value in collecting short-term outcomes data in routine practice at both 1 and 2 years.

Predictors of physical functioning after total hip arthroplasty: a systematic review

OBJECTIVE

The objective of this systematic review of the literature was to identify the predictors of functional outcome after total hip arthroplasty (THA).

METHOD

A systematic literature search in Web of Science, CINAHL, EMBASE and PubMed was conducted on 23 June 2015. The articles were selected based on their quality, relevance and measurement of the predictive factor. The level of evidence of all studies was determined using the GRADE rating scheme.

RESULTS

The initial search resulted in 1092 citations. After application of the inclusion and exclusion criteria, 33 articles met our eligibility criteria and were graded. Included studies were classified as level of evidence low (11), moderate (17) or high (5). Of the included studies, 18 evaluated body mass index (BMI), 17 evaluated preoperative physical functions, 15 evaluated age, 15 evaluated gender and 13 evaluated comorbidity. There was strong evidence suggesting an association between BMI, age, comorbidity, preoperative physical functions and mental health with functional outcome after THA. There was weak evidence suggesting an association between quadriceps strength and education with functional outcome after THA. The evidence was inconsistent for associations with gender and socioeconomic status and functional outcome following THA. We found limited evidence suggesting that alcohol consumption, vitamin D insufficiency and allergies were predictors of functional outcome following THA.

CONCLUSIONS

We have identified multiple predictors of functional outcome after THA, which will enable general practitioners and orthopaedic surgeons to better predict the improvement in physical functioning for their patients with THA. They can use this information to provide patient-specific advice regarding the referral for THA and the expected outcomes after THA. Further research with consistent measurement tools, outcomes and duration of follow-up across studies is needed to confirm the influence of these factors.

Coexistent lumbar spine disorders have a crucial impact on the clinical outcome after total hip replacement

BACKGROUND

Degenerative hip and spine disease are known to frequently coexist. Lumbar spine disorders (LSDs), as opposed to other patient-related factors, are disregarded in the assessment of the clinical outcome after total hip replacement (THR). This prospective study investigates the influence of LSDs on the pre- and postoperative health-related quality of life and functional outcome of patients undergoing THR.

METHODS

According to clearly defined criteria, 42 patients scheduled for cementless THR were assigned either to the LSD (13 patients with LSDs) or non-LSD group (29 patients without LSDs). A clinical assessment was performed preoperatively as well as 12, 24 and 60 months postoperatively using the Harris hip score (HHS), the Western Ontario and McMaster University osteoarthritis index (WOMAC) and the 36-item short form health survey (SF-36).

RESULTS

The statistical analysis comparing the pre- and postoperative status within both groups showed an ongoing improvement of mean HHS and WOMAC after THR. The non-LSD group had a significantly higher postoperative HHS and WOMAC after 12, 24 and 60 months as well as SF-36 after 24 and 60 months. The LSD group improved significantly in the HHS at 24 and 60 months and the WOMAC at 12, 24 and 60 months postoperatively, whereas the SF-36 improvement was not significant. Comparison of preoperative data in both groups revealed a significantly higher SF-36 in the non-LSD group but no difference between the HHS and WOMAC. At each postoperative assessment, the HHS, WOMAC and SF-36, including its physical and mental health sum scores, were significantly higher in the non-LSD group, except for the WOMAC after 60 months.

CONCLUSION

Owing to their crucial impact on hip function scores and health-related quality of life, it is recommended to consider LSDs preoperatively in studies dealing with the clinical outcome after THR.

[Influence of preoperative bone mass density in periprosthetic bone remodeling after implantation of ABG-II prosthesis: A 10-year follow-up]

INTRODUCTION

Preoperative bone mass index has shown to be an important factor in peri-prosthetic bone remodelling in short follow-up studies.

MATERIAL AND METHODS

Bone density scans (DXA) were used to perform a 10-year follow-up study of 39 patients with a unilateral, uncemented hip replacement. Bone mass index measurements were made at 6 months, one year, 3 years, 5 years, and 10 years after surgery. Pearson coefficient was used to quantify correlations between preoperative bone mass density (BMD) and peri-prosthetic BMD in the 7 Gruen zones at 6 months, one year, 3 years, 5 years, and 10 years.

RESULTS

Pre-operative BMD was a good predictor of peri-prosthetic BMD one year after surgery in zones 1, 2, 4, 5 and 6 (Pearson index from 0.61 to 0.75). Three years after surgery it has good predictive power in zones 1, 4 and 5 (0.71-0.61), although in zones 3 and 7 low correlation was observed one year after surgery (0.51 and 0.57, respectively). At the end of the follow-up low correlation was observed in the 7 Gruen zones. Sex and BMI were found to not have a statistically significant influence on peri-prosthetic bone remodelling.

CONCLUSION

Although preoperative BMD seems to be an important factor in peri-prosthetic remodelling one year after hip replacement, it loses its predictive power progressively, until not being a major factor in peri-prosthetic remodelling ten years after surgery.

Endoprosthesis and obesity

INTRODUCTION

Obesity represents a significant risk factor in the pathophysiology of degenerative changes in coxarthrosis.

OBJECTIVE

The study aims to investigate obesity as a risk factor in the examined sample comprising 136 patients who underwent hip endoprothesis implantation.

MATERIAL AND METHODS

The series comprised 136 patients with a hip endoprosthesis implanted, where the patients' BMI, amount of blood used, duration of surgery, number of assistants, and type of anaesthesia were observed. Wounds and late post-operative complications, infections, haemorrhage, vein thrombosis, endoprosthesis dislocations, length of inpatient stay, start of physical therapy and full weight-bearing were also observed. The observation period lasted six months on average.

DISCUSSION

In simple terms, the three greatest factors when implanting a hip endoprosthesis are as follows: properties of the endoprosthesis, the orthopaedic surgeon's skill and experience, and individual characteristics of the patient, i.e. age, sex, health condition, body weight, BMI, adequate physical therapy.

CONCLUSION

We believe that the implantation of a hip endoprosthesis should be postponed for patients with a BMI exceeding 29.99. Such patients should receive endocrine treatment, they should undergo a weight loss programme in order to reduce their body weight and in order to reduce their BMI to under 29.99.

Obesity in total hip arthroplasty--does it really matter? A meta-analysis

BACKGROUND AND PURPOSE

Discussion persists as to whether obesity negatively influences the outcome of hip arthroplasty. We performed a meta-analysis with the primary research question of whether obesity has a negative effect on short- and long-term outcome of total hip arthroplasty.

METHODS

We searched the literature and included studies comparing the outcome of hip arthroplasty in different weight groups. The methodology of the studies included was scored according to the Cochrane guidelines. We extracted and pooled the data. For continuous data, we calculated a weighted mean difference and for dichotomous variables we calculated a weighted odds ratio (OR). Heterogeneity was calculated using I(2) statistics.

RESULTS

15 studies were eligible for data extraction. In obese patients, dislocation of the hip (OR = 0.54, 95% CI: 0.38-0.75) (10 studies, n = 8,634), aseptic loosening (OR = 0.64, CI: 0.43-0.96) (6 studies, n = 5,137), infection (OR = 0.3, CI: 0.19-0.49) (10 studies, n = 7,500), and venous thromboembolism (OR = 0.56, CI: 0.32-0.98) (7 studies, n = 3,716) occurred more often. Concerning septic loosening and intraoperative fractures, no statistically significant differences were found, possibly due to low power. Subjective outcome measurements did not allow pooling because of high heterogeneity (I(2) = 68%).

INTERPRETATION

Obesity appears to have a negative influence on the outcome of total hip replacement.