Birmingham Hip Resurfacing vs Total Hip Arthroplasty: A Matched-Pair Comparison of Clinical Outcomes

Establishing minimal clinically important differences and patient acceptable symptom state thresholds following birmingham hip resurfacing

INTRODUCTION

Birmingham Hip Resurfacing (BHR) has emerged as a compelling and innovative alternative to total hip arthroplasty (THA), especially among young, active patients. However, the Minimal Clinically Important Difference (MCID) and the Patient Acceptable Symptom State (PASS) thresholds have not yet been determined for patients undergoing BHR. Therefore, the current study aimed to (1) determine the MCID and PASS thresholds for both the Hip disability and Osteoarthritis Outcome Score (HOOS)-Pain and HOOS physical function shortform (PS), for patients who underwent BHR; and (2) identify factors influencing the achievement of MCID and PASS for HOOS-Pain and HOOS-PS.

METHODS

Prospectively collected data from patients undergoing BHR was analyzed. Patients with osteoarthritis and completed preoperative and 1-year postoperative PROMs were included. Distribution-based and anchored-based approaches were used to estimate MCID and PASS, respectively. The optimal cut-off point for PASS thresholds was calculated using the Youden index.

RESULTS

MCID for HOOS-Pain and PS were calculated to be 9.2 and 9.3, respectively. The PASS threshold for HOOS-Pain and PS were ≥ 77.7 and ≥ 87.3, respectively. The current study identified several factors affecting postoperative achievement of thresholds. Baseline Mental Component Summary (MCS) scores were a predictor for achieving MCID for postoperative HOOS-Pain, achieving MCID for postoperative HOOS-PS, achieving PASS for postoperative HOOS-Pain, and achieving PASS for postoperative HOOS-PS. Furthermore, baseline HOOS-Pain was a significant predictor for achieving MCID for postoperative HOOS-PS, achieving PASS for postoperative HOOS-Pain, and achieving PASS for postoperative HOOS-PS.

CONCLUSIONS

MCID and PASS thresholds were established for HOOS-Pain and PS domains following BHR with most patients achieving these clinically meaningful benchmarks. Additionally, several factors affecting achievement of MCID and PASS were identified, including modifiable risk factors that may allow clinicians to implement optimization strategies and further improve outcomes.

Anterior Approach to Hip Arthroplasty with Early Mobilization Key for Reduced Hospital Length of Stay

Background and Objectives: This study aimed to explore the preoperative factors related to early mobilization and length of stay (LOS) after total hip arthroplasty and the benefits of the anterior approach over the traditional lateral approach. Materials and Methods: Every patient benefits from information regarding details of the surgery approach, possible intra, and postoperative complications, post-operator medical care, and steps in the early mobilization protocol. The patient underwent a pre-anesthetic evaluation, was checked for preoperatory vital function, and was reevaluated for mobilization at 6, 12, 24, 36, 48, and 96 h after total hip arthroplasty using the anterior versus lateral approach. Results: The result of the statistical calculations indicates the independent negative risk factors for reaching the mobilization target: age with a coefficient of -0.046, p = 0.0154 and lateral approach with a relative risk of 0.3802 (95% CI: 0.15-0.90), p = 0.0298. Statistical data concerning the length of stay (LOS) showed significant differences in the total days spent in the hospital. The patients who were operated on using the lateral approach presented a higher body mass index than those with the anterior approach, but this difference did not reach the threshold of statistical significance. Conclusions: In our study, patient mobilization is crucial to reduce LOS.

Resurfacing Hip Arthroplasty Is a Safe and Effective Alternative to Total Hip Arthroplasty in Young Patients: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed at comparing resurfacing hip arthroplasty (RHA) and total hip arthroplasty (THA) in terms of rate of complications, revisions, functional outcomes, blood loss, operative time and metal ions levels. The search was conducted on three databases (PubMed, Cochrane and Web of Science) updated until 13 October 2022. The inclusion criteria were RCTs) written in the English language, with no time limitation, comparing RHA and THA. Among the retrieved 4748 articles, 18 RCTs were eligible for a total of 776 patients (mean age 53.1 ± 5.0). A meta-analysis was performed. RHA reported significantly lower blood loss compared to THA (p < 0.001) but with longer operative time (p < 0.001). No statistically significant difference was found between RHA and THA in terms of complications (12.08% and 16.24%, respectively) and revisions (6.32% and 6.14%, respectively). Both RHA and THA provide excellent clinical results in a population of young and active patients. Functional outcomes were not significantly different between the groups. Moreover, no significant difference in metal ion levels was found. These findings provide evidence concerning the safety and clinical effectiveness of RHA. Because of its bone-preserving properties, the lack of drawbacks and good outcomes, RHA appears to be a valid alternative to THA in young and active patients.

Comparison of the long-term cause of failure and survivorship of four hundred and twenty seven metal-on-metal hip arthroplasties: resurfacing versus large head total hip arthroplasty

Introduction

Comparison of mid- to long-term cause of failure and survivorship of metal-on-metal (MoM) resurfacing hip arthroplasty (RHA) and large head total hip arthroplasty (THA) remains sparse. This study aimed to identify and compare the cause of failure and survivorship of MoM RHA and THA at a minimum ten year follow-up.

Methods

Four hundred twenty-seven MoM hip arthroplasties (286 THA and 141 RHA) were retrospectively analyzed at a mean follow-up of 13 ± three years. Causes of failure were reported as MoM specific (i.e., adverse reaction to metal debris (ARMD) and painful hip with ion elevation) or MoM non-specific (i.e., fracture, infection, and dislocation). Chromium (Cr) and cobalt (Co) ion levels and Co/Cr ratio were compared. Survivorship was compared according to the cause of failure with revision as the endpoint.

Results

The rate of ARMD was significantly higher in THA (OR = 2.9 [95%-CI: 1–7]; p = 0.02). No significant difference was detected in failure rate due to other causes between the two groups (p = 0.2–0.9). Ion levels and Co/Cr ratio were both significantly higher in THA (p < 0.01). Survivorship was significantly lower in THA compared to RHA at ten years [89% (95%-CI: 85%–91%) vs 96% (95%-CI: 91%–98%); p = 0.01] and 15 years [73% (95%-CI: 67%–78%) vs 83% (95%-CI: 73%–90%); p = 0.01].

Conclusion

RHA survivorship was significantly higher at any time point. Failure rate due to ARMD was significantly higher in THA while no significant difference in other causes of failure was observed between the two groups. This result emphasizes the role of fretting corrosion at the head-neck junction (i.e., trunnionosis) with significantly higher ion levels and Co/Cr ratio dissociation in THA.

Minimum Five-Year Outcomes of Hip Resurfacing: Propensity-Score Matched Against Total Hip Arthroplasty Control Groups

BACKGROUND

The aim of this study is to evaluate clinical outcomes of patients undergoing Birmingham hip resurfacing (BHR) with a minimum 5-year follow-up and compare these outcomes to 2 matched control groups of patients undergoing either direct anterior approach (DAA) or posterior approach (PA) total hip arthroplasty (THA).

METHODS

Data between September 2008 and April 2015 were retrospectively reviewed. Male patients were included if they underwent a THA or BHR with minimum 5-year patient-reported outcomes. BHR patients were propensity-score matched in a 1:1 ratio to 2 control groups of patients: one group who underwent DAA THA and one group who underwent PA THA.

RESULTS

Fifty BHR patients were propensity-score matched to 2 control groups: 50 cases of PA THA and 50 cases of DAA THA. Both control groups were well matched with respect to demographics. The BHR 5-year patient-reported outcomes were comparable to both control groups. The BHR cohort compared favorably to the PA THA group with no significant differences in their average Forgotten Joint Score (77.9, 79.4, P = .84 respectively) and the number of patients reporting a score greater than or equal to 50 were also comparable, 41 (82%), 42 (84%), P = .79 respectively.

CONCLUSION

BHR yielded good functional status and outcomes, which compared favorably with control groups of DAA THA and PA THA. Decision-making should be based upon other factors such as potential risk factors, the surgeon's and patient's preferences, and the patient's physical demand.

Hip resurfacing arthroplasty and total hip arthroplasty in the same patient: which do they prefer?

INTRODUCTION

Hip resurfacing arthroplasty (HRA) is an alternative to conventional total hip arthroplasty (THA) with potential advantages of preserving femoral bone stock and the ability to participate in higher impact activities. This study compares outcomes, satisfaction and preference in patients who underwent HRA in 1 hip and THA on the contralateral side.

METHODS

62 Patients with an HRA in 1 hip and a contralateral THA were retrospectively identified at 3 centres, consisting of 38 males and 24 females with 53 patients (85.5%) undergoing HRA first. A survey regarding satisfaction and preference for each procedure and outcome scores were obtained.

RESULTS

Patients were younger (51.5 vs. 56.6 years, p = 0.002) and had longer follow-up on the HRA hip (11.0 vs. 6.0 years, p < 0.001). HRA was associated with larger increase in Harris Hip Score from preoperative to final follow-up (35.8 vs. 30.6, p = 0.035). 18 Patients (29.0%) preferred HRA, 19 (30.6%) preferred THA and 25 (40.3%) had no preference (p = 0.844). When asked what they would choose if they could only have 1 surgery again, 41 (66.1%, p < 0.001) picked HRA. Overall satisfaction (p = 0.504), willingness to live with their HRA versus THA for the rest of their life (p = 0.295) and recommendation to others (p = 0.097) were similar.

CONCLUSIONS

Although HRA is associated with risks related to metal-on-metal bearings, it showed greater increase in patient-reported outcomes and a small subjective preference amongst patients who have undergone both conventional and resurfacing arthroplasty.

Safety and Efficacy of Same-Day Hip Resurfacing

Same-day discharge (SDD) surgery in total hip arthroplasty (THA) has been shown to have similar outcomes to non-SDD THA in select patient populations. Hip resurfacing arthroplasty (HRA) is an alternative to THA for young, active patients, making them ideal candidates for SDD. This study compared the safety and efficacy of non-SDD HRA and SDD HRA for specific postoperative outcomes. An electronic data warehouse query was performed for procedures labeled "hip resurfacing." Data collected included demographics, surgical factors, and quality metrics. Statistical analyses were evaluated using a graphing and statistics software program. Categorical variables were analyzed with chi-square tests and continuous variables with Student's t tests, with P<.05 deemed significant. Sixty-three of 274 total HRAs were enrolled in this SDD HRA protocol. No significant difference was observed between SDD HRA and non-SDD HRA baseline characteristics. On postoperative day 0, 98.41% of SDD HRA recipients were discharged successfully. The SDD HRA recipients had shorter stays, with 1.59% requiring a hospital stay of 2 days or more compared with 56.87% of non-SDD HRA recipients (P<.0001). The non-SDD HRA recipients were found to have shorter surgical times than SDD HRA recipients (104.74 vs 125.51 minutes, P=.01). Rates of infection, periprosthetic fractures, emergency department visits, and hospital readmissions were equivalent (P=.99). Same-day discharge HRA is a safe and effective procedure with similar outcomes to non-SDD HRA regarding infections, fractures, emergency department visits, and readmissions. The major benefit of SDD is a shorter hospital stay that may lead to decreased cost while preserving and enhancing quality of care and patient satisfaction. [Orthopedics. 2020;43(6):e595-e600.].

Is the Survivorship of Birmingham Hip Resurfacing Better Than Selected Conventional Hip Arthroplasties in Men Younger Than 65 Years of Age? A Study from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

The Birmingham Hip Resurfacing (BHR) prosthesis is the most commonly used metal-on-metal hip resurfacing arthroplasty device. The current manufacturer-recommended target demographic for the BHR is male patients, younger than 65 years requiring a femoral head size of ≥ 50 mm. Female patients, older patients, and individuals with smaller femoral-head diameter (≤ 50 mm) are known to have higher revision rates. Prior studies suggest that the survivorship of the BHR when used in the target demographic is comparable with that of primary conventional THA, but comparing survivorship of the most durable hip resurfacing arthroplasty device to the survivorship of all conventional THA prostheses is not ideal because the THA group comprises a large number of different types of prostheses that have considerable variation in prosthesis survival. A more informative comparison would be with the THA implants with the best survivorship, as this might help address the question of whether survivorship in the BHR target population can be improved by using a well-performing conventional THA.

QUESTIONS/PURPOSES

We compared the difference in cumulative percent revision, reasons for revision and types of revision for procedures reported to the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) using the BHR prosthesis (femoral-head size > 50 mm) and three conventional THA prostheses identified as having the lowest 10-year cumulative percent revision in the currently recommended BHR target population to ask: (1) Does the BHR have a lower cumulative revision rate than the group of three conventional THA prostheses? (2) Is there a difference in the revision diagnosis between the BHR and the three best conventional THA prostheses? (3) What is the difference in the components used for a revision of a BHR compared with the three best conventional THA prostheses?

METHODS

Data reported to the AOANJRR between September 1, 1999 and December 31, 2018 was used for this analysis. This study period includes almost the entire use of the BHR in Australia. The AOANJRR is a large national joint registry with almost 100% completeness, high accuracy, rigorous validation, and little to no loss to follow-up. The study population included males younger than 65 years that had received one hip replacement procedure for osteoarthritis. All patients with bilateral procedures, no matter the time interval between hips, were excluded. Only BHR prostheses with a femoral-head size ≥ 50 mm and conventional THA prostheses with femoral head sizes ≥ 32 mm and either ceramic-on-ceramic or metal, ceramic, ceramicized metal-on-crosslinked polyethylene (XLPE) bearings were included. These femoral head sizes and bearings were selected because they reflect modern conventional THA practice. There is no difference in the revision rate of these bearings in the AOANJRR. There were 4790 BHR procedures and 2696 conventional THA procedures in the study group. The mean (± SD) age for BHR procedures was 52 ± 7.8 years and 56 ± 7.1 years for conventional THA procedures. All comparative analyses were adjusted for age. Other demographics data including American Society Anesthesiologists (ASA) score and BMI were only included in AOANJRR data collection since 2012 and 2015, respectively, and have not been included in this analysis because of the low use of BHR in Australia since that time. The maximum follow-up was 18.7 years for both groups and mean follow-up of 11.9 years for the BHR and 9.3 years for the conventional THA group. Revision rates were determined using Kaplan-Meier estimates of survivorship to describe the time to the first revision, with censoring at the time of death or closure of the database at the time of analysis. A revision was defined as removal, replacement or addition of any component of a joint replacement. Revisions can be further classified as major revisions (removal of a component articulating with bone-usually the stem and/or the shell) or minor revisions (removal of other components-usually the head and/or the liner). The unadjusted cumulative percent revision after the primary arthroplasty (with 95% confidence intervals) was calculated and compared using Cox proportional hazard models adjusted for age.

RESULTS

The BHR prosthesis had a statistically higher rate of all-cause revision at 17 years than the selected conventional THA prostheses (HR 2.77 [95% CI 1.78 to 4.32]; p < 0.001). The revision diagnoses differed between the groups, with the BHR demonstrating a higher revision rate for loosening after 2 years than the conventional THA protheses (HR 4.64 [95% CI 1.66 to 12.97]; p = 0.003), as well as a higher fracture rate during the entire period (HR 2.57 [95% CI 1.24 to 5.33]; p = 0.01). There was a lower revision rate for infection for the BHR compared with the THA group in the first 5 years, with no difference between the two groups after this time. All revisions of the BHR were major revisions (such as, removal or exchange of the femoral and/or acetabular components) and this occurred in 4.5% of the primary BHR procedures. Major revision was the most common type of revision for primary THA accounting for 1.7% of all primary THA procedures. Minor revisions (head, inset or both) were undertaken in a further 0.6% of primary THA procedures.

CONCLUSIONS

Given the increasing revision risk of the BHR compared with better-performing conventional THA prostheses in the target population, we recommend that patients be counseled about this risk. We suggest that a THA with proven low revision rates might be the better choice, particularly for patients who are concerned about implant durability. Well-controlled prospective studies that show appreciable clinically important differences in patient-reported outcomes and functional results favoring the BHR over conventional THA prostheses using modern bearings are needed to justify the use of the BHR in view of this revision risk.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Hip Replacement or Hip Resurfacing with a Highly Cross-Linked Polyethylene Acetabular Bearing: A Qualitative and Quantitative Preference Study

Background

Most surgeons strongly prefer total hip arthroplasty (THA) over hip resurfacing arthroplasty (HRA). However, it is unknown whether patients prefer the results of 1 procedure over the other. The purpose of this study was to answer 3 questions: (1) Do patients with an HRA on 1 side and a THA on the other notice a difference? (2) Do patients have a preference? (3) What are the reasons for their preference?

Methods

Between 1998 and 2012, 332 patients underwent staged bilateral hip arthroplasties with cementless THA on 1 side and HRA on the other, with a highly cross-linked polyethylene acetabular component used for both. Patient preferences, Harris hip scores, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were recorded by blinded examiners. Patients provided reasons for their preference in semi-structured interviews using both quantitative and qualitative measures.

Results

The mean follow-up was 11 years (range, 7 to 21 years). Of 324 patients with complete data, 279 (86%) preferred the HRA, 19 (6%) preferred the THA, and 26 (8%) had no preference. The most common reasons for preference for the HRA were better balance (n = 143), felt more normal (n = 141), better activity participation/more reliable hip during sports (n = 139), and stronger on stairs (n = 129). A fair or poor outcome was reported by the patient after 4 HRAs and 7 THAs. The remainder of the patients reported improved function and satisfactory pain relief and range of motion for both hips.

Conclusions

In conclusion, most patients in this study preferred the side on which the HRA had been done. Since essentially all current hip prostheses perform well, a paired bilateral study may be the optimal way to determine patient preferences and values of HRA compared with THA.

Level of Evidence

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Robotic-assisted unicompartmental knee arthroplasty has a greater early functional outcome when compared to manual total knee arthroplasty for isolated medial compartment arthritis

Aims

The primary aim of the study was to compare the knee-specific functional outcome of robotic unicompartmental knee arthroplasty (rUKA) with manual total knee arthroplasty (mTKA) for the management of isolated medial compartment osteoarthritis. Secondary aims were to compare length of hospital stay, general health improvement, and satisfaction between rUKA and mTKA.

Methods

A powered (1:3 ratio) cohort study was performed. A total of 30 patients undergoing rUKA were propensity score matched to 90 patients undergoing mTKA for isolated medial compartment arthritis. Patients were matched for age, sex, body mass index (BMI), and preoperative function. The Oxford Knee Score (OKS) and EuroQol five-dimension questionnaire (EQ-5D) were collected preoperatively and six months postoperatively. The Forgotten Joint Score (FJS) and patient satisfaction were collected six months postoperatively. Length of hospital stay was also recorded.

Results

There were no significant differences in the preoperative demographics (p ⩾ 0.150) or function (p ⩾ 0.230) between the groups. The six-month OKS was significantly greater in the rUKA group when compared with the mTKA group (difference 7.7, p < 0.001). There was also a greater six-month postoperative EQ-5D (difference 0.148, p = 0.002) and FJS (difference 24.2, p < 0.001) for the rUKA when compared to the mTKA. No patient was dissatisfied in the rUKA group and five (6%) were dissatisfied in the mTKA, but this was not significant (p = 0.210). Length of stay was significantly (p < 0.001) shorter in the rUKA group (median two days, interquartile range (IQR) 1 to 3) compared to the mTKA (median four days, IQR 3 to 5).

Conclusion

Patients with isolated medial compartment arthritis had a greater knee-specific functional outcome and generic health with a shorter length of hospital stay after rUKA when compared to mTKA.

Cite this article: Bone Joint Res 2019;9(1):15–22.

Hip resurfacing generates a more physiological gait than total hip replacement: A case-control study

BACKGROUND

Restoration of the constitutional joint anatomy after hip replacement favours physiological peri-articular soft-tissue tension and kinematics, and is likely to be functionally beneficial. Hip resurfacing (HR) and conventional total hip replacement (THR) are two different options for replacing degenerated hips, and are likely to result in different anatomical reconstruction. We initiated this study to investigate the differences in gait performance between these two prosthetic options, and aimed to answer the following questions: (1) does HR result in better restoration of the frontal hip anatomical parameters, (2) and generate a more physiological gait compared to THR? (3) Does the quality of the anatomical restoration after THR influence gait performance?

HYPOTHESES

Our hypothesis was that a better anatomical restoration using HR versus THR would produce more physiological (symmetric) gait.

METHODS

We retrospectively reviewed 52 patients who had unilateral primary osteoarthritis successfully treated by replacement (40 THRs and 12 HRs). Hip anatomical parameters were measured on standing pelvic radiographs on both the prosthetic and the contralateral healthy hips. Patients undertook gait assessment under both normal and stress conditions at a mean follow-up of 14 months (7 to 16 months). Gait performances were compared between HR and THR, and the relationship between gait performances and quality of frontal anatomical restoration (estimated on radiograph) were assessed.

RESULTS

Compared to the native contralateral side, the HR procedure tended to decrease all independent anatomical radiographic parameters with the exception of the vertical centre of rotation offset, whilst the THR procedure tended to increase them; the difference between HR and THR was only statistically significant for femoral offset and global horizontal offset (increased after THR while reduced after HR). Only 50% of THR and 25% of HR procedures closely anatomically (±15%) recreated both global horizontal offset and global vertical offset. Under normal conditions (normal walking speed and flat ramp), the gait was fairly symmetric for both the HR and the THR patients with a symmetry index of 0.62% and 3.14% respectively. At high walking speed (stress conditions), the symmetry index degraded for both groups, but the gait remained more symmetric in the HR group (2.09%), compared to the THR group (5.74%); nevertheless, the difference remained not statistically significant (p=0.159). We were unable to detect any significant relationship between gait performances and radiographically measured hip frontal anatomical parameters.

DISCUSSION/CONCLUSIONS

HR procedure is more consistent than conventional THR in generating a more physiological gait under stress conditions. Radiographic estimation of the quality of the frontal anatomical hip restoration is of poor value to predict gait performances of THR patients.

LEVEL OF EVIDENCE

III - retrospective case-control study with prospective data collection.

Gait after Birmingham Hip Resurfacing: an age-matched controlled prospective study

Aims

The aim of this study was to assess the functional gain achieved following hip resurfacing arthroplasty (HRA).

Patients and Methods

A total of 28 patients (23 male, five female; mean age, 56 years (25 to 73)) awaiting Birmingham HRA volunteered for this prospective gait study, with an age-matched control group of 26 healthy adults (16 male, ten female; mean age, 56 years (33 to 84)). The Oxford Hip Score (OHS) and gait analysis using an instrumented treadmill were used preoperatively and more than two years postoperatively to measure the functional change attributable to the intervention.

Results

The mean OHS improved significantly from 27 to 46 points (p < 0.001) at a mean of 29 months (12 to 60) after HRA. The mean metal ion levels at a mean 32 months (13 to 60) postoperatively were 1.71 (0.77 to 4.83) µg/l (ppb) and 1.77 (0.68 to 4.16) µg/l (ppb) for cobalt and chromium, respectively. When compared with healthy controls, preoperative patients overloaded the contralateral good hip, limping significantly. After HRA, patients walked at high speeds, with symmetrical gait, statistically indistinguishable from healthy controls over almost all characteristics. The control group could only be distinguished by an increased push-off force at higher speeds, which may reflect the operative approach.

Conclusion

Patients undergoing HRA improved their preoperative gait pattern of a significant limp to a symmetrical gait at high speeds and on inclines, almost indistinguishable from normal controls. HRA with an approved device offers substantial functional gains, almost indistinguishable from healthy controls.

Cite this article: Bone Joint J 2019;101-B:1423–1430.

Anatomic study on the blood supply to the femoral head following hip resurfacing using the posterior approach

OBJECTIVES

The aim of this study was to investigate femoral head perfusion following cadaveric hip resurfacing using the posterior approach.

METHODS

This cadaveric study involved injecting Higgins India ink into the common iliac arteries and evaluating the distribution of ink in the resurfaced heads using the modified Spalteholz technique. The study consisted of 2 parts. The 1st part involved utilisation of 22 cadaveric hips for establishing the injection and histological technique. The 2nd part of the study included 4 control cadaveric hips and 12 cadaveric hips with posterior approach hip resurfacing. Each specimen was divided into 15 zones (12 head zones and 3 neck zones) to evaluate detailed geographic distribution of dye-containing blood vessels.

RESULTS

All 4 controls had good flow of ink to all head zones and the neck region. In all the resurfaced heads, there was good flow to all the neck zones. 6 resurfaced specimens had no dye flow to any of the head zones. In the remaining 6, dye-stained vessels were seen variably in the anterior and middle zones but were consistently absent in the posterior zones of the head. Zones representing the antero-inferior parts of femoral head had the maximum flow of ink, followed by zones representing middle-inferior parts.

CONCLUSIONS

Posterior approach for hip resurfacing arthroplasty results in vascular insult to the femoral head, with posterior zones more affected than the anterior zones. The persistence of the dye in the intraosseous blood vessels of the neck and in anteroinferior head may be a source of revascularisation of the femoral head after posterior approach hip resurfacing.

Patient-reported outcomes in hip resurfacing versus conventional total hip arthroplasty: a register-based matched cohort study of 726 patients

Background and purpose - The theoretical mechanical advantages of metal-on-metal hip resurfacing (MoM-HR) compared with conventional total hip arthroplasty (THA) have been questioned. Studies including measures of patient-reported function, physical activity, or health-related quality of life have been sparse. We compared patient-reported outcomes in MoM-HR patients with a matched group of patients with conventional THA at 7 years post-surgery. Patients and methods - Patients and patient data were retrieved from the Swedish Hip Arthroplasty Register. The case group, consisting of 363 patients with MoM-HR, was matched 1:1 with a control group, consisting of patients with a conventional THA. Patients were sent a postal patient-reported outcome measures (PROM) questionnaire including the Hip Disability and Osteoarthritis Outcome Score (HOOS), EQ-5D, and VAS pain. We used multivariable linear regression analyses to investigate the influence of prosthesis type. Results - 569 patients (78%) returned the questionnaire with complete responses (299 MoM-HRs and 270 conventional THAs). MoM-HR was associated with better scores in HOOS function of daily living (4 percentage units) and HOOS function in sport and recreation (8 percentage units) subscales. Type of prosthesis did not influence HOOS quality of life, HOOS pain, HOOS symptoms, EQ-5D index, hip pain, or satisfaction as measured with visual analog scales. Interpretation - At mean 7 years post-surgery, patients with hip resurfacing had somewhat better self-reported hip function than patients with conventional THA. The largest difference between groups was seen in the presumed most demanding subscale, i.e., function in sport and recreation.

Relationship Between PROMIS Computer Adaptive Tests and Legacy Hip Measures Among Patients Presenting to a Tertiary Care Hip Preservation Center

BACKGROUND

Legacy hip outcome measures may be burdensome to patients and sometimes yield floor or ceiling effects. Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive tests (CATs) allow for low-burden data capture and limited ceiling and floor effects.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine whether the PROMIS CAT domains demonstrate correlation against commonly used legacy patient-reported outcome measures in a population of patients presenting to a tertiary care hip preservation center. The authors hypothesized the following: (1) PROMIS CAT scores based on physical function (PF), pain interference (PIF), pain behavior, and pain intensity would show strong correlation with the following legacy scores: modified Harris Hip Score (mHHS), International Hip Outcome Tool-12 (iHOT-12), Hip Outcome Score (HOS) Sports and Activities of Daily Living subscales, and Veterans RAND-6D (VR-6D) utility measure. (2) The mental and physical health portions of the VR-6D legacy measure would show weak correlation with mental- and psychosocial-specific PROMIS elements-depression, anxiety, fatigue, sleep, and ability to participate in social roles and activities. (3) All PROMIS measures would exhibit fewer floor and ceiling effects than legacy scores.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

Prospective data were collected on 125 patients in the hip preservation clinics. Enrollees completed legacy scores (visual analog scale for pain, mHHS, iHOT-12, HOS, and VR-6D) and PROMIS CAT questionnaires (PF, PIF, pain behavior, anxiety, depression, sleep, social roles and activities, pain intensity, fatigue). Spearman rank correlations were calculated, with r_s values of 0 to 0.3 indicating negligible correlation; 0.3 to 0.5, weak correlation; 0.5 to 0.7, moderately strong correlation; and >0.7, strong correlation. Floor and ceiling effects were evaluated.

RESULTS

As anticipated, the PF-CAT yielded strong correlations with the iHOT-12, mHHS, HOS-Sports, HOS-Activities of Daily Living, and VR-6D, with r_s values of 0.76, 0.71, 0.81, 0.87, and 0.71, respectively. The PIF-CAT was the only pain score to show moderately strong to strong correlation with all 14 patient-reported outcome measures. A strong correlation was observed between the VR-6D and the social roles and activities CAT ( r_s = 0.73). The depression CAT had a significant floor effect at 19%. No additional floor or ceiling effect was present for any other legacy or PROMIS measure.

CONCLUSION

The PF-CAT shows strong correlation with legacy patient-reported outcome scores among patients presenting to a tertiary care hip preservation center. The PIF-CAT also correlates strongly with legacy and PROMIS measures evaluating physical and mental well-being. PROMIS measures are less burdensome and demonstrate no floor or ceiling effects, making them a potential alternative to legacy patient-reported outcome measures for the hip.

Computer-assisted navigation in Birmingham hip resurfacing: A case report

Component malpositioning during Birmingham hip resurfacing increases the risk for component wear, metallosis, component loosening, and the likelihood of dislocation and revision surgery. Computer-assisted navigation can increase the accuracy to which components are placed, and the utilization of this technology in Birmingham hip resurfacing is increasing. The present report summarizes the accuracy of acetabular component positioning in a Birmingham hip resurfacing case utilizing navigation. Intraoperative C-arm fluoroscopy following the use of the navigation tool confirmed excellent seating, positioning, and stability of the acetabular component. In addition, post-operative antero-posterior radiographs confirmed device accuracy and revealed a stable joint with no evidence of acetabular loosening or femoral fracture. Computer-assisted navigation may therefore be an effective tool to improve the accuracy of component positioning during Birmingham hip resurfacing.

Cementless total hip arthroplasty for osteonecrosis and osteoarthritis produce similar results at ten years follow-up when matched for age and gender

PURPOSE

The aim of this study was to compare the clinical outcomes of cementless total hip arthroplasty (THA) used for the treatment of osteonecrosis of the femoral head (ONFH) and for osteoarthritis (OA) at a mean ten years follow-up.

METHODS

Case-control study of 78 patients (86 hips) who underwent THA for ONFH treatment (ONFH group). Patients were matched for age and sex to 78 patients (86 hips) who underwent THA for OA (OA group). We compared the clinical and patient-reported outcomes, implant survival rates, and rates of complications between the groups.

RESULTS

There were no between-group differences in the Harris Hip Score and in the following patient-reported outcomes at the last follow-up: Japanese Orthopedic Association Hip-Disease Evaluation Questionnaire (JHEQ) pain and movement scores and the Physical Component Summary and Role/Social Component Summary scores of Short Form-36 (SF-36). However, the mental score of the JHEQ, the Mental Component Summary score of SF-36, and The Visual Analog Scale score for satisfaction were lower for the ONFH group than for OA group. The rate of complication was equivalent between the groups: 5% for the ONFH group and 3% for the OA group. The ten year implant survival rate was equivalent between the groups, at 97.5% for the ONFH group and 98.2% for the OA group.

CONCLUSION

The functional outcomes, implant survival, and rate of complications for cementless THAs are comparable at a mean follow-up of ten years for ONFH and OA.