Quality of total hip arthroplasty health care based on four years of patient-reported outcomes in the Netherlands.

BACKGROUND: Joint arthroplasty registries have incorporated patient-reported outcomes (PROs) to evaluate outcomes from a patients' perspective to improve total hip arthroplasty (THA). To draw valid conclusions on PROs, a minimum response rate (RR) of 60% is advised. This study investigated (1) if the quality of THA health care based on PROs improved over the years in the Netherlands, (2) if RRs improved over the years, and (3) difference in PROs over the years in hospitals with RR ≥ 60% compared to RR < 60%. METHODS: Longitudinal study with publicly available datasets from 2016 to 2019. Primary outcome was increase/decrease in PRO change scores including 95%CI ranges over the years between preoperatively and 3 months postoperatively (pre-3 m), and 12 months postoperatively (pre-12 m). Improved quality of health care was arbitrary defined as when ≥ 3 of 4 included scores or ranges were statistically significant improved. Secondary outcome was increase/decrease in RRs over the years. Subgroups RR ≥ 60% and RR < 60% were compared. RESULTS: Hospitals (%) collecting THA PROs increased from 78 to 92%. EQ VAS change score increased over the years, and 95%CI ranges of EQ VAS, EQ-5D descriptive system and NRS pain during activity decreased over the years at pre-3 m (p < 0.05). All THA pre-12 m PRO change scores and 95%CI ranges remained equal (p > 0.05). Pre-3 m RR remained equal (around 43%, p = 0.107) and pre-12 m RR decreased 9% (49% to 40%, p = 0.008). Pre-3 m subgroup RR ≥ 60% was too small to analyse (5%). No difference was found between pre-12 m subgroups (RR ≥ 60% = 16%), p > 0.05). CONCLUSIONS: Quality of THA health care based on PROs seems equal in the Netherlands between 2016 and 2019. Although more hospitals participated in PRO collection, low RRs with large IQRs are observed and only 16% of the hospitals achieved the advised RR ≥ 60%. Multiple recommendations are provided to improve PRO collection and use.

No significant difference in early clinical outcomes of custom versus off-the-shelf total knee arthroplasty: a systematic review and meta-analysis.

PURPOSE: The purpose of this systematic review and meta-analysis was to collect, synthesise and critically appraise findings of clinical studies that report outcomes of custom total knee arthroplasty (TKA). The hypothesis was that, compared to off-the-shelf (OTS) TKA, custom TKA would yield better surgical, clinical and radiographic outcomes. METHODS: This systematic review and meta-analysis was performed in accordance with the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). On 8 February 2021, two authors independently searched and screened articles using MEDLINE®, Embase® and the Cochrane Library without restriction on date of publication. Findings from eligible articles were narratively synthesised and tabulated, and when ≥ 3 comparative studies reported the same outcome, results were pooled and summarised in forest plots. Quality assessments of the studies were done according to the guidelines of the Joanna Briggs Institute (JBI) Checklists. RESULTS: A total of 15 articles were eligible for data extraction, of which 9 were case-control studies reporting on 929 custom versus 998 OTS TKA, 5 were case series reporting on results of 587 custom TKA, and 1 was a cross-sectional study reporting on results of 44 custom versus 132 OTS TKA. Five studies that compared early revision rates found the overall effect in favour of OTS TKA (odds ratio (OR), 0.4; p = n.s.) but the result did not reach statistical significance. Four studies found no statistically significant difference in KSS knee (standardised mean difference (SMD), - 0.10; p = n.s.) and function (SMD, 0.03; p = n.s.), and five studies found no statistically significant difference in range of motion (SMD, 0.02; p = n.s.). One study that compared bone-implant fit between custom and three OTS tibial components found no overhang but revealed under-coverage of up to 18% in knees with custom tibial baseplates. CONCLUSION: Custom TKA demonstrated no significant benefits compared to OTS TKA in terms of pooled clinical outcomes, but had considerably higher early revision rates. The findings of the present systematic review and meta-analysis suggest the need for studies with better comparable groups and standardisation of reporting outcomes amongst studies, that could increase the quality of evidence and enable pooling of results in future meta-analyses. LEVEL OF EVIDENCE: Level IV.

Robot-assisted knee arthroplasty improves component positioning and alignment, but results are inconclusive on whether it improves clinical scores or reduces complications and revisions: a systematic overview of meta-analyses.

PURPOSE: The purpose of this systematic overview was to identify, synthesise and critically appraise findings of meta-analyses on robot-assisted versus conventional unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). The hypothesis was that robotic assistance would reduce complications and revision rates, yield better clinical scores, and improve component positioning and alignment. METHODS: Two researchers independently conducted a literature search using Embase®, MEDLINE®, Web of Science, Allied and Complementary Medicine™ and Cochrane Database of Systematic Reviews on 2 November 2020 for meta-analyses (Level I-IV) on robotic assistance in UKA and/or TKA. Outcomes were tabulated and reported as weighted mean difference (WMD), risk ratio (RR) or weighted odds ratio (WOR), and were considered statistically significant when p < 0.05. RESULTS: A total of ten meta-analyses were identified; four on robot-assisted UKA (n, 1880 robot-assisted vs. 2352 conventional UKA; follow-up, 0 to 60 months), seven on robot-assisted TKA (n, 4567 robot-assisted vs. 5966 conventional TKA; follow-up, 0 to 132 months). Of the meta-analyses on UKA, one found that robotic assistance reduced complication rates (relative risk (RR), 0.62), one found that it improved clinical scores (weighted mean difference (WMD), 19.67), three found that it extended operation times (WMD, 15.7 to 17.1 min), and three found that it improved component positioning and alignment (WMD, - 1.30 to - 3.02 degrees). Of the meta-analyses on TKA, two found that robotic assistance improved clinical scores (WMD, 1.62-1.71), two found that that it extended surgery times (WMD, 21.5-24.26 min), and five found that it improved component positioning and alignment (WMD, - 0.50 to - 10.07 degrees). None of the meta-analyses reported differences in survivorship between robot-assisted versus conventional knee arthroplasty. CONCLUSION: Robot-assisted knee arthroplasty enabled more accurate component positioning and placement within target zones, but extended operation time considerably. Although robotic assistance improved component positioning, its benefits regarding clinical scores, patient satisfaction and implant survivorship remains to be confirmed. Finally, this overview revealed that six of the ten meta-analyses were of 'critically low quality', calling for caution when interpreting results. LEVEL OF EVIDENCE: IV.

Insufficient evidence to confirm benefits of custom partial knee arthroplasty: a systematic review.

PURPOSE: The purpose of this systematic review was to synthesise the available literature and critically appraise current evidence on the functional and radiographic outcomes as well as reoperation and revision rates of custom partial knee arthroplasty, i.e., unicompartmental knee arthroplasty (UKA), bicompartmental knee arthroplasty (BKA), and patellofemoral arthroplasty (PFA). MATERIAL AND METHODS: This systematic review was performed in accordance with the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and a protocol was registered with Prospero. On 25 May 2021, two authors independently searched and screened Level I-IV studies that reported on outcomes of custom partial knee arthroplasty using the databases of MEDLINE®, EMBASE®, and the Cochrane Library without restriction on date of publication. Findings from eligible articles were synthesised and tabulated, and quality assessments were done according to the guidelines of the Joanna Briggs Institute (JBI) Checklists. RESULTS: Fifteen articles were eligible for data extraction, of which two comparative and four case series were on custom UKA (follow-up, 0-9 months), one comparative and five case series on custom BKA (follow-up, 0.25-72 months), and three case series on custom PFA (follow-up, 2-119 months). Three studies on custom UKA reported mean Knee Society Score (KSS) Knee of 86-94 and mean KSS Function of 94-95, and two studies on custom BKA reported mean KSS Knee of 90-94 and KSS function of 81, whereas one study on custom PFA reported KSS Knee of 91 and KSS Function of 89. Custom implants tended to have less bone-implant mismatch compared to off the shelf (OTS) implants. Revision rates were 3-25% for custom UKA (at 0-109 months), 3-5% for custom BKA (at 12-72 months), and 0-14% for custom PFA (at 2-119 months). CONCLUSION: Due to the small number of comparative studies and lack of consistency in reported outcomes, it remains difficult to ascertain the benefits of custom partial knee arthroplasty. Anecdotal evidence suggests that, compared to OTS implants, custom implants result in less bone-implant mismatch and that 78-91% of patients are either satisfied or very satisfied after custom partial knee arthroplasty. LEVEL OF EVIDENCE: IV.

A Patient-Reported Outcome Tool to Triage Total Hip Arthroplasty Patients to Hospital or Video Consultation: Pilot Study With Expert Panels and a Cohort of 1228 Patients.

BACKGROUND: The digital transformation in health care has been accelerated by the COVID-19 pandemic. Video consultation has become the alternative for hospital consultation. It remains unknown how to select patients suitable for video consultation. OBJECTIVE: This study aimed to develop a tool based on patient-reported outcomes (PROs) to triage total hip arthroplasty (THA) patients to hospital or video consultation. METHODS: A pilot study with expert panels and a retrospective cohort with prospectively collected data from 1228 THA patients was executed. The primary outcome was a PRO triage tool to allocate THA patients to hospital or video consultation 6 weeks postoperatively. Expert panels defined the criteria and selected the patient-reported outcome measure (PROM) questions including thresholds. Data were divided into training and test cohorts. Distribution, floor effect, correlation, responsiveness, PRO patient journey, and homogeneity of the selected questions were investigated in the training cohort. The test cohort was used to provide an unbiased evaluation of the final triage tool. RESULTS: The expert panels selected moderate or severe pain and using 2 crutches as the triage tool criteria. PROM questions included in the final triage tool were numeric rating scale (NRS) pain during activity, 3-level version of the EuroQol 5 dimensions (EQ-5D-3L) questions 1 and 4, and Oxford Hip Score (OHS) questions 6, 8, and 12. Of the training cohort, 201 (201/703, 28.6%) patients needed a hospital consultation, which was statistically equal to the 150 (150/463, 32.4%) patients in the test cohort who needed a hospital consultation (P=.19). CONCLUSIONS: A PRO triage tool based on moderate or severe pain and using 2 crutches was developed. Around 70% of THA patients could safely have a video consultation, and 30% needed a hospital consultation 6 weeks postoperatively. This tool is promising for selecting patients for video consultation while using an existing PROM infrastructure.

Exergaming as a Functional Test Battery in Patients Who Received Arthroscopic Ankle Arthrodesis: Cross-sectional Pilot Study.

BACKGROUND: Recently, movement-based videogames (exergames) have gained popularity in improving the rehabilitation process after surgery. During exergaming, participants are physically challenged as the game component stimulates adherence to the training program. There is no literature on the effect of exergame training interventions in patients who received arthroscopic ankle arthrodesis. OBJECTIVE: This pilot study assessed the potency of an existing exergaming tool for the rehabilitation program of patients who received arthroscopic ankle arthrodesis. METHODS: A cross-sectional pilot study was performed, in which patients who received arthroscopic ankle arthrodesis (n=8) were subjected to an exergaming protocol. Gait analysis was performed with a treadmill system. A healthy age-matched control group (n=10) was used as the control group. RESULTS: The patient group was capable of performing exergaming exercises and they showed no floor or ceiling effect. Only in case of the overall stability, the patient group performed significantly less better than the control group (P=.03). Gait analysis showed equal step length with increased external rotation of the affected limb. CONCLUSIONS: Exergaming seems to be a valuable tool for measuring the ability of patients who received AAA to perform activities of daily living and it has the potential to individualize rehabilitation programs. When exergaming is systematically integrated with patient-reported outcome measures and activity tracking, it has the potential to improve the quality of care.

Clinical and surgical outcomes of robot-assisted versus conventional total hip arthroplasty: a systematic overview of meta-analyses.

Robot-assisted total hip arthroplasty (THA), in comparison to conventional THA, improves radiographic outcomes, but it remains unclear whether it alters complication rates, clinical and functional outcomes, and implant survival. The purpose of this systematic overview was to summarize the findings of the most recent meta-analyses that compare clinical and surgical outcomes of robot-assisted versus conventional THA. Two readers independently conducted an electronic literature search, screening and data extraction from five electronic databases. Inclusion criteria were: meta-analyses evaluating robot-assisted versus conventional THA in terms of radiographic outcomes, clinical and functional scores, and complications and revision rates. The literature search returned 67 records, of which 14 were duplicates and 49 were excluded, leaving three meta-analyses published within the past two years for data extraction and analysis. The present overview of meta-analyses suggests that, compared to conventional THA (n = 3011), robot-assisted THA (n = 1813) improves component placement and reduces intraoperative complications. The overview also affirms that robot-assisted THA could extend surgery by 20 minutes, and increases risks of postoperative heterotopic ossification, dislocation, and revision. None of the meta-analyses found significant differences in clinical or functional scores between robot-assisted and conventional THA. Future studies and reviews should make a clear distinction between active and semi-active robotic assistance, address technology matureness, and describe the experience of surgeons with robotic assistance.

What is the minimum response rate on patient-reported outcome measures needed to adequately evaluate total hip arthroplasties?

BACKGROUND: Unknown is which response rate on patient-reported outcome measures (PROMs) is needed to both obtain an accurate outcome and ensure generalizability in evaluating total hip arthroplasty (THA) procedures. Without an evidence based minimum response rate (MRR) on THA PROMs, it is possible that hospitals report invalid patient-reported outcomes (PROs) due to a too low response rate. Alternatively, hospitals may invest too much in achieving an unnecessary high response rate. The aim of this study is to gain an insight into the MRR on PROMs needed to adequately evaluate THA procedures from a clinical perspective. METHODS: Retrospective study on prospective collected data of primary, elective THA procedures was performed. MRR was investigated for each PROM (NRS pain at rest, NRS pain during activity, EQ-5D-3L, HOOS-PS, anchor function, OHS, anchor pain and NRS satisfaction) separately to calculate the primary outcome: MRR for the THA PROMs set. MRR on a PROM needed to have (condition 1.) similar PRO change score (3 month score minus preoperative score) including confidence interval, (condition 2.) maintaining the influence of each change score predictor and (condition 3.) equal distribution of each predictor, as those of a 100% PROM response rate group. Per PROM, a 100%-group was identified with all patients having the PRO change score. Randomly assessed groups of 90% till 10% response rate (in total 90 groups) were compared with the 100%-group. Linear mixed model analyses and linear regressions were executed. RESULTS: The MRR for the THA PROMs set was 100% (range: 70-100% per PROM). The first condition resulted in a MRR of 60%, the second condition in a MRR of 100% and the third condition in a MRR of 10%. CONCLUSIONS: A 100% response rate on PROMs is needed in order to adequately evaluate THA procedures from a clinical perspective. All stakeholders using THA PROs should be aware that 100% of the THA patients should respond on both preoperative and 3 month postoperative PROMs. For now, taking the first step in improving evaluation of THA for quality control by achieving at least two of the three conditions of MRR, advised is to require a response rate on PROMs of 60% as the lower limit.

Reliability of two different measuring techniques with computer tomography for penetration and distribution of cement in the proximal tibia after total knee arthroplasty.

BACKGROUND: To evaluate the reliability of two different techniques for measuring penetration and distribution of the cement mantle in the proximal tibia after total knee arthroplasty (TKA) with Computer Tomography (CT) in vivo. METHODS: Standardized CT scans of the proximal tibia were taken 1 to 2 years after total knee arthroplasties implanted with a surface cementing technique. These prospectively acquired transversal CT images of the surface of the proximal tibia were divided into four quadrants and were assessed once manually and once with a numerical computing program (MATLAB® Update 2, The MathWorks, Inc.) based on Hounsfield Units by one of the researchers. The assessments were repeated by the same and a second researcher. The ratio cement/trabecular bone was calculated 1, 3 and 5 mm distal of the tibia tray per quadrant. Kruskall-Wallis tests with multiple pairwise comparisons (Dunn's test) were used to determine differences between the quadrants. Intra- and inter-rater reliability as well as the inter method reliability were assessed with the Intraclass Correlation Coefficient (ICC) per level of depth and with Bland-Altman plots. RESULTS: A total of 92 CT scans were included. The intra- and inter-rater reliability of the manual method ranged from 0.22 and 0.52. The intra- and inter-rater reliability of the matlab method varied between 0.98 to 0.99. The median percentage cement measured with the matlab method 1 mm underneath the tibial tray varied between 82 and 88%; at 3 mm depth between 38 and 54% and at 5 mm between 15 and 25%. There was significantly (p < 0.05) less cement in the antero-medial quadrant compared to the antero-lateral and postero-lateral quadrant at 3 mm and 5 mm depth. CONCLUSIONS: Distribution and penetration of cement in the proximal tibia in a total knee arthroplasty can be measured reliably with CT in combination with the matlab method presented in this manuscript. This method can be used for clinical purposes as well as for scientific research. TRIAL REGISTRATION: METC-nr: 06-104 Dossier NL14807.098.06/versie 06.

Response rate and costs for automated patient-reported outcomes collection alone compared to combined automated and manual collection.

BACKGROUND: The response rate on patient-reported outcome measurements (PROMs) necessary to adequately evaluate a treatment and improve patient care is unknown. Hospitals generally aim for the highest possible response rate without insight into the increase in costs involved. This study aimed to investigate which PROMs response rate is achievable in relation to the costs in an orthopaedic practice. METHODS: In an observational study, patients planned for orthopaedic surgery were asked to participate per surgical procedure (5769 surgical procedures at 5300 patients). Patient-reported outcomes (PROs) collection with a digital online automated PROMs collection system (minimal effort) was compared to a combined automated system and manual collection (maximal effort). Response rate was calculated preoperative and at two postoperative time points separately, and on all three time points together. Costs were calculated for the study period, per year and per surgical procedure. Calculations were executed for all surgical procedures and for three subgroups: knee arthroplasty, hip arthroplasty and anterior cruciate ligament reconstruction (ACLR). RESULTS: Using maximal effort the response rate increased for all surgical procedures compared to minimal effort; the preoperative response rate from 86% to 100% and the postoperative response rates from 55% to 83% (3 or 6 months) and 53% to 83% (12 months). Concerning the response at all three time points for all surgical procedures, minimal effort resulted in 44% response rate and increased to 76% with maximal effort. Lowest postoperative response rates were found in the ACLR group for both maximal and minimal effort. A costs difference of €5.55-€5.98 per surgical procedure between maximal and minimal effort was found. CONCLUSIONS: A two times higher PROMs response rate for patients responding at all three time points (44% versus 76%) is achievable with maximal effort compared to the use of an automated PROMs collection system only. Manual collection adds a cost of €5.5-€6 per surgical procedure to automated PROMs collection alone. It is debatable if these additional costs are justifiable from a value-based health care perspective as the response rate for adequate evaluation of a treatment is still unknown.

Comparison of Mini-Midvastus and Conventional Total Knee Arthroplasty with Clinical and Radiographic Evaluation: A Prospective Randomized Clinical Trial with 5-Year Follow-up.

BACKGROUND: The main objective of this prospective randomized study was to compare the clinical and radiographic outcomes of the mini-midvastus (MMV) approach with the conventional approach for total knee arthroplasty at the 5-year follow-up. METHODS: Ninety-seven patients (100 knees) with osteoarthritis were assigned to the MMV group or to a group receiving conventional total knee arthroplasty. Intraoperative and postoperative clinical data were collected. At 6 weeks and at 1, 2, and 5 years postoperatively, the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Oxford Knee Score (OKS), the Knee Society Score (KSS), and the Short Form (SF)-12 were completed. Radiographs of the knee were made preoperatively and at 1 day and 1 and 5 years postoperatively. Computed tomography (CT) scans were performed 2 years postoperatively. RESULTS: In the MMV group, the mean skin incision was 2.5 cm shorter (p < 0.001) and the mean duration of the operation was 6 minutes longer than in the conventional total knee arthroplasty group (p < 0.05). Eight patients in the conventional group had a lateral parapatellar retinacular release compared with 1 in the MMV group; the difference was significant (p = 0.01). Three intraoperative complications, including 2 small lateral femoral condylar fractures and 1 partial patellar tendon laceration, occurred in the MMV group. Seven patients in the MMV group had postoperative blisters; all of them had a relatively large femoral component and 4 of them were large men. The radiographs and CT scans of the prostheses showed no significant differences between the MMV and conventional groups except for the posterior slope of the tibial component. In addition, no significance differences were detected between the groups with respect to the KOOS, OKS, KSS, and SF-12 scores determined at the 6-week and the 1, 2, and 5-year follow-up evaluations. CONCLUSIONS: In the rehabilitation period and at the short and mid-term follow-up, no relevant clinical and radiographic differences were found between the MMV and the conventional approach for total knee arthroplasty, making the advantage of MMV total knee arthroplasty cosmetic. We discourage the use of the MMV approach in large male patients because of the increased number of intraoperative complications and skin blisters postoperatively. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

The Effect of Door Openings on Numbers of Colony Forming Units in the Operating Room during Hip Revision Surgery.

BACKGROUND: The aim of this study was to investigate the effect of door opening rates on air quality in the operation room during hip revision surgery by measuring the number of colony forming units per cubic meter (CFU/m(3)). METHODS: During 70 hip revision operations the number of CFU/m(3) was measured at four time points. Factors that may influence air quality were recorded, including the number of persons present, duration of surgery, and door opening rates. The measured CFU/m(3) was dichotomized as either acceptable (≤20 CFU/m(3)) or not acceptable (>20 CFU/m(3)). To determine whether door openings were associated with CFU/m(3) values, we used generalized linear mixed models to model the dichotomized repeatedly measured CFU/m(3) values. RESULTS: The median number of door openings per operation was eight (range, 0-72), the median duration of surgery was 145 min (range, 60-285), and the median number of persons present during surgery was eight (range, 5-10). Adjusted for number of persons in the operation room and duration of surgery, the number of door openings per operation was associated (odds ratio [OR] 1.05 [95% confidence interval {CI} 1.02-1.09]; p = 0.003) with an unacceptable number of CFU/m(3). CONCLUSIONS: In conclusion, a substantial association between number of door openings and an unacceptable number (>20) of CFU/m(3) was found. Adjusted for number of persons in the operation room and duration of surgery, every door opening increased the odds of unacceptable CFU/m(3) values by 5%. Number of persons present during surgery and duration of surgery were not related to CFU/m(3).

A quantitative non-invasive assessment of femoroacetabular impingement with CT-based dynamic simulation--cadaveric validation study.

BACKGROUND: Femoroacetabular impingement (FAI) is caused by an anatomic deviation of the acetabular rim or proximal femur, which causes chronic groin pain. Radiological identification of FAI can be challenging. Advances in imaging techniques with the use of computed tomography (CT) scan enable 3D simulation of FAI. We made an experimental cadaveric validation study to validate the 3D simulation imaging software. METHODS: The range of motion (ROM) of five cadaveric hips was measured using an electromagnetic tracking system (EMTS). Specific marked spots in the femur and pelvis were created as reproducible EMTS registration points. Reproducible motions were measured. Hips were subsequently imaged using high-resolution CT after introduction of artificial cam deformities. A proprietary software tool was used, Articulis (Clinical Graphics) to simulate the ROM during the presence and absence of the induced cam deformities. RESULTS: According to the EMTS, 13 of the 30 measured ROM end-points were restricted by > 5° due to the induced cam deformities. Using Articulis, with the same 5° threshold, we correctly detected 12 of these 13 end point limitations and detected no false positives. The median error of the measured limitations was 1.9° (interquartile range 1.1° - 4.4°). The maximum absolute error was 5.4°. CONCLUSIONS: The use of this dynamic simulation software to determine the presence of motion limiting deformities of the femoroacetabular is validated. The simulation software is able to non-invasively detect a reduction in achievable ROM, caused by a cam type deformity.

Validation of a measuring technique with computed tomography for cement penetration into trabecular bone underneath the tibial tray in total knee arthroplasty on a cadaver model.

BACKGROUND: In total knee arthroplasty (TKA), cement penetration between 3 and 5 mm beneath the tibial tray is required to prevent loosening of the tibia component. The objective of this study was to develop and validate a reliable in vivo measuring technique using CT imaging to assess cement distribution and penetration depth in the total area underneath a tibia prosthesis. METHODS: We defined the radiodensity ranges for trabecular tibia bone, polymethylmethacrylate (PMMA) cement and cement-penetrated trabecular bone and measured the percentages of cement penetration at various depths after cementing two tibia prostheses onto redundant femoral heads. One prosthesis was subsequently removed to examine the influence of the metal tibia prostheses on the quality of the CT images. The percentages of cement penetration in the CT slices were compared with percentages measured with photographs of the corresponding transversal slices. RESULTS: Trabecular bone and cement-penetrated trabecular bone had no overlap in quantitative scale of radio-density. There was no significant difference in mean HU values when measuring with or without the tibia prosthesis. The percentages of measured cement-penetrated trabecular bone in the CT slices of the specimen were within the range of percentages that could be expected based on the measurements with the photographs (p = 0.04). CONCLUSIONS: CT scan images provide valid results in measuring the penetration and distribution of cement into trabecular bone underneath the tibia component of a TKA. Since the proposed method does not turn metal elements into artefacts, it enables clinicians to assess the width and density of the cement mantle in vivo and to compare the results of different cementing methods in TKA.

The predictive value of radiostereometric analysis for stem survival in total hip arthroplasty. A systematic review.

BACKGROUND: The high precision of radiostereometric analysis (RSA) has enabled us to predict long-term implant survival with a small sample of patients followed for a relatively short period of time. The purpose of our systematic review was to validate the predictive value of two-year RSA results on long-term survival of different types of primary total hip arthroplasty stems. METHODS: We systematically reviewed literature to determine the maximum total point motion (MTPM), distal migration and rotation of stem designs and correlated these values to survival rates for aseptic loosening of these specific stems in arthroplasty registries. RESULTS: We included 32 studies describing migration of 15 different stem designs. The mean MTPM for straight polished cemented stems was 1.35 mm, for other cemented stems 0.83 mm and for other uncemented stems 1.50 mm. No data were available for the uncemented collared stem. Mean distal migration for straight polished cemented stems was 1.24 mm, for other cemented stems 0.26 mm, the uncemented collared stem 0.40 mm and for other uncemented stems 0.66 mm. Internal rotation was presented for 13 stems and all stems rotated into retroversion. All stems showed 10-year survival rates of >97% corrected for aseptic loosening. DISCUSSION: Reporting RSA results in a universal way including interpretation of outliers could improve the predictive value of RSA, allowing this technique to be an important tool during the phased introduction of new implant designs. However, a quality assessment of the data by an experienced reviewer is essential.

Treatment of pseudotumors after metal-on-metal hip resurfacing based on magnetic resonance imaging, metal ion levels and symptoms.

Peri-prosthetic pseudotumor formation can be a severe complication following Metal-on-Metal hip resurfacing arthroplasty (MoMHRA), with limited data on the optimal management of this complication. The aims of this study were (1) to evaluate the prevalence and severity of pseudotumors in a consecutive cohort of 248 MoMHRA (214 patients, mean follow-up 4.6 years, range: 1 - 8.2), and (2) to present a clinical guideline for their treatment based on severity grading with Metal Artefact Reduction Sequence Magnetic Resonance Imaging, metal ion levels and symptoms. Pseudotumor prevalence was 36.3%: 61 mild, 25 moderate and four were graded severe. Five revisions followed, all in symptomatic patients with elevated metal ion levels. Pseudotumor severity grading allowed us to be conservative with revision surgery for mild and moderate MoM disease.

External validation of the discharge of hip fracture patients score.

PURPOSE: This paper reports the external validation of a recently developed instrument, the Discharge of Hip fracture Patients score (DHP) that predicts discharge location on admission in patients living in their own home prior to hip fracture surgery. METHODS: The DHP (maximum score 100 points) was applied to 125 hip fracture patients aged 50 or more years admitted to an academic centre in the northern part of The Netherlands (Groningen cohort). The characteristics of this cohort, sensitivity, specificity and positive and negative predictive value (PPV, NPV) of the DHP for discharge to an alternative location (DAL) were calculated and compared with the original cohort of hip fracture patients from the western part of The Netherlands (Delft cohort). Scoring 30 points or higher indicated DAL. RESULTS: The Groningen cohort was younger compared to the Delft cohort, (mean age 75.4 vs. 78.5 years, P = 0.005) but was more often classified ASA III/IV (46.4% vs. 25.2%, P < 0.001). Sensitivity of the DHP for DAL in the Groningen cohort was 75% (vs. 83.8%), specificity of 66.7% (vs. 64.7%) and a PPV of 86.3% (vs. 79.2%), compared to the Delft cohort. CONCLUSION: External validation of the DHP was successful; it predicted discharge location of hip fracture patients accurately in another Dutch cohort, the sensitivity for DAL was somewhat lower but the PPV higher. Therefore, the DHP score is a useful valid and easily applied instrument for general hip fracture populations.

Do clinical characteristics and outcome in nonagenarians with a hip fracture differ from younger patients?

AIM: To compare clinical characteristics and outcome of nonagenarian hip fracture patients with younger patients aged 65-89 years. METHODS: This was a cohort follow-up study of admissions for a hip fracture between 2005-2010 (mean follow up of 3.5 years) in two teaching hospitals in The Netherlands; 230 nonagenarians and 1014 patients aged 65-89 years were included. Clinical characteristics, adverse events, mobility and mortality were compared. RESULTS: Nonagenarians were more likely to be female and anemic (both P<0.001), and had more trochanteric fractures (P=0.005). The number of American Society of Anesthesiologists III/VI classified patients did not differ between the two groups. During the hospital stay, adverse events were more frequently observed in nonagenarians compared with younger patients (P<0.001). The length of stay was significantly longer in nonagenarians (P<0.001), and the 90-day readmission rate was similar. Absolute mortality was higher in nonagenarians (P<0.001), excess mortality, however, was comparable. Before admission, 40.0% of the nonagenarians lived in their own home, and 40.9% had returned 3 months postfracture. The rate of returning to their own home was lower compared with younger patients (P<0.001). Prefracture mobility was worse in nonagenarians compared with the younger group, but 3 months after discharge, the number of patients that regained prefracture mobility was comparable in both age groups. CONCLUSIONS: Nonagenarian hip fracture patients differ significantly from younger patients aged 65-89 years with respect to clinical characteristics and long-term outcome. However, almost half of the nonagenarians returned to their own home and more than half regained their prefracture level of mobility. Given these findings, prevention strategies for hip fracture and adverse events during hospital stay that focus particularly on frail nonagenarians are highly recommended.

More than half of hip fracture patients do not regain mobility in the first postoperative year.

AIM: To measure functional recovery and determine risk factors for failure to return to the prefracture level of mobility of hip fracture patients 1 year postoperatively. METHODS: A prospective cohort follow-up study of 390 hip fracture patients aged 65 years and older was carried out. Patients were stratified in categories based on prefracture mobility: mobile without aid, with aid in- and outdoors, or only mobile indoors. Immobile patients were excluded. Risk factors for not regaining prefracture mobility were identified. RESULTS: Nearly half of all patients regained their prefracture level of mobility after 1 year. Mobile patients without an aid were less likely to return to their prefracture mobility level compared with patients who were mobile with aid or mobile indoors. After 1 year, 18.7% of all patients had become immobile. Most important independent risk factors for failure to return to the prefracture level of mobility were a limited prefracture level of activities of daily living and a delirium during admission. CONCLUSIONS: The risk not to regain prefracture mobility is highest in mobile patients without an aid. The risk of becoming immobile is higher in those having a lower prefracture mobility. Activities of daily living dependence and delirium were the main risk factors for not regaining mobility.

[Femoroacetabular impingement: frequently missed in patients with chronic groin pain]. / Femoro-acetabulaire impingement: vaak gemist bij chronische liesklachten.

Femoroacetabular impingement is a diagnosis that is often missed in patients with chronic groin pain. The condition often appears in young athletes. An anatomic deformity of the femoral head and the acetabular ridge causes an impingement that damages the subchondral tissue. This damage can result in sharp pain in the groin during specific hip movements and the acetabular labrum may also be ruptured. Diagnosing femoroacetabular impingement and a labral tear can be a challenge. We present the case of a 19-year-old male who twisted his right hip joint during a game of football. Physiotherapy only aggravated the pain. Further diagnostics showed femoroacetabular impingement and a labral tear. Arthroscopic intervention in the hip joint by an orthopedic surgeon lead to immediate pain relief, and two years after surgery the patient is still free of pain and has returned playing sport at his previous level. Femoroacetabular impingement can be a cause of chronic groin pain in young athletes. Hip arthroscopy is a safe and effective treatment, enabling the patient to return to playing sport at their previous level.