BACKGROUND AND PURPOSE:Ankle fractures are common, and open reduction and internal fixation (ORIF) is standard treatment for unstable injuries. Surgical site infections (SSI) remain a significant clinical challenge. We aimed to estimate incidence and to identify patient- and treatment-related factors associated with SSI after ankle ORIF. METHODS:In this retrospective cohort, we included all adults (≥ 18 years) who underwent ankle ORIF at 2 trauma centers in northern Sweden from 2015 to 2024. Data from medical records covered demographics, comorbidities, injury characteristics, surgical details, and peri/postoperative care. The primary outcome was incidence of SSI and the secondary outcome was independent factors associated with SSI. SSI was defined as an infection occurring at or near the surgical incision within 30 days after surgery or up to 1 year later in the presence of an implant. RESULTS:We included 781 patients (mean age 54 years; 61% women). SSI occurred in 11%; 27% of infections underwent revision surgery, and 39 infections (43%) were categorized as fracture-related infection (FRI). Other complications included urinary tract infections (2.2%), pneumonia (0.8%), deep vein thrombosis (0.5%), and pulmonary embolism (0.4%). In adjusted analyses, higher odds of SSI were observed with smoking (aOR 2.3, 95% confidence interval [CI] 1.1-4.8, P = 0.02), initial external fixation (aOR 5.6, CI 1.7-17.6, P = 0.004), and longer operative time (OR per minute 1.0, CI 1.0-1.0, P = 0.004). The American Society of Anesthesiologists (ASA) class estimate suggested increased risk but was imprecise (aOR 9.7, CI 1.0-93.6, P = 0.049). Age, sex, and open fracture were not associated with SSI in the adjusted model. CONCLUSION:After ankle ORIF, SSI occurred in 11%. Smoking, initial external fixation, and longer operative time were associated with higher risk of infection, while ASA estimate was imprecise. These findings support perioperative risk mitigation (e.g., smoking cessation and operative efficiency) and motivate study of physiological risk (ASA).
BACKGROUND AND PURPOSE:Robotic-assisted total knee arthroplasty (rTKA) has been proposed to improve component positioning but evidence on its effect on implant survival is limited. We aimed to compare implant survival between rTKA and conventional total knee arthroplasty (cTKA) overall and due to peri-prosthetic joint infection (PJI). METHODS:We included all rTKAs performed in Finland from April 2021 until May 2023, all implanted with Triathlon TKA using MAKO robotic-arm assist. Propensity score matching was used to form a control group with similar characteristics for the same time period. Primary survival endpoint was first revision due to any cause within 12 months after the index surgery. PJI and non-PJI revisions were considered secondary outcomes. Kaplan-Meier (KM) analysis and Cox proportional hazards regression were used to assess implant survival and between-group contrasts hazard ratios (HR) with 95% confidence intervals (CIs), respectively. RESULTS:1,318 fixed bearing rTKAs were compared with a control group of 1,318 cTKAs. Revision-free survival at 12 months after index surgery did not differ between groups. KM estimates were 99.1% (CI 98.5-99.7) for rTKA and 98.6% (CI 98.0-99.3) for cTKA with HR 0.61 (CI 0.28-1.34). The rTKA group demonstrated better PJI-free survival at 12 months (HR 0.29, CI 0.10-0.90). Overall, PJI was the most common reason for revision. At the end of available follow-up, the estimated overall survival was 97.7% (CI 94.9-100.0) for rTKA and 97.9% (CI 96.6-99.2) for cTKA. CONCLUSION:No difference in all-cause revision risk was observed between rTKA and cTKA groups. However, within the first 12 months, fewer revisions due to PJI occurred in the rTKA group.
BACKGROUND AND PURPOSE:Optimal treatment for displaced femoral neck fractures (FNF) in patients aged 60-69 years remains controversial. We aimed to compare mortality and short-term clinical outcomes after total hip arthroplasty (THA), hemiarthroplasty (HA), or internal fixation (IF) after displaced FNF. METHODS:We included 3,325 patients aged 60-69 years with displaced FNF recorded in the Swedish Hip Fracture Register. 1-year mortality and 4-month functional outcomes (maintenance of independent living and outdoor walking ability) were analyzed. Analyses were stratified by American Society of Anesthesiologists (ASA) class (I-II vs III-IV). RESULTS:Overall, 1-year mortality was 8.3%. Adjusted analyses showed higher 1-year mortality after HA (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.7-3.6) and IF (OR 2.3, CI 1.6-3.3) compared with THA. Survival analyses demonstrated lower survival probabilities after HA and IF compared with THA in ASA III-IV but not in ASA I-II patients. THA was associated with higher odds of maintaining independent living (IF: OR 0.40, CI 0.20-0.86; HA: OR 0.09, CI 0.04-0.17) and maintaining outdoor walking ability (IF: OR 0.35, CI 0.24-0.50; HA: OR 0.26, CI 0.16-0.43) in ASA I-II patients. In ASA III-IV patients, estimates were closer to unity. CONCLUSION:THA was associated with lower mortality in ASA III-IV and better functional outcomes in ASA I-II.
BACKGROUND AND PURPOSE:Healthcare value might be improved with radiographic peer review to evaluate surgical quality. While numerous radiographic recommendations are available, peer review differs by including expert appraisal. We aimed to assess the predictive value of radiographic peer review in identifying primary hip and knee arthroplasties at higher risk of aseptic revision. METHODS:A retrospective observational cohort study was conducted to compare aseptic revision rates with peer review scores, using data from the JointCare registry of South Africa. Matching and weighting was applied among cohorts, and revision rates were compared using Cox proportional hazards regression. RESULTS:The sample consisted of 7,218 arthroplasties performed between January 2020 and June 2023. 5,126 arthroplasties were scored as "good," 1,931 as "acceptable," and 161 as "suboptimal." "Suboptimal" arthroplasties had a significantly higher hazard ratio (HR) for aseptic revision than "good" arthroplasties (HR 9.4, 95% confidence interval [CI] 3.6-24.5). Furthermore, "suboptimal" total hip (HR 11.4, CI 2.6-49.7), total knee (HR 5.7, CI 1.3-25.6), and medial unicompartmental knee arthroplasties (HR 9.8, CI 2.0-47.4) had significantly higher HRs than "good" ones. Overall and for each procedure, "acceptable" arthroplasties had higher HRs than "good" arthroplasties; however, these results were not statistically significant. CONCLUSION:Radiographic review by experienced arthroplasty surgeons was able to identify arthroplasties at higher risk of aseptic revision. As such, radiographic review could be used for quality improvement by identifying directions for surgical improvement.
BACKGROUND AND PURPOSE:Patient-reported outcome measures need to reflect true differences rather than measurement artifacts resulting from translations when scores are compared across countries. We evaluated the measurement invariance of the English, Dutch, Danish, and French Oxford Hip Score (OHS) and Oxford Knee Score (OKS) in patients undergoing hip and knee arthroplasty. METHODS:OHS and OKS responses from patients undergoing primary hip or knee arthroplasty for osteoarthritis between 2019 and 2022 were included from national and single-center registries in the United Kingdom, the Netherlands, Denmark, and Switzerland. We evaluated unidimensionality, monotonicity (Hi > 0.3) and local independence (Yen Q3 > 0.20 above the average indicating independence) in each language version separately. Model fit was considered satisfactory when Comparative Fit Index (CFI) and Tucker-Lewis Index (TLI) were ≥ 0.95, root mean square error of approximation (RMSEA) ≤ 0.06, and standardized root mean square residual (SRMR) ≤ 0.08. Measurement invariance across languages was analyzed with multiple group-confirmatory factor analysis on full, random, and matched sample datasets. RESULTS:Across the hip and knee cohorts, unidimensionality was acceptable in the English (n = 21,108 and 28,230), Dutch (n = 36,792 and 29,651), Danish (n = 815 and 1,015), and French (n = 590 and 459) versions. RMSEA ranged from 0.072 to 0.092 for OHS, and from 0.057 to 0.061 for OKS and other fit indices were acceptable. The multiple group-confirmatory factor analysis showed acceptable measurement invariance across languages for both scores, with changes in RMSEA < 0.15 and CFI < 0.1 across gradually more constrained models. CONCLUSION:Measurement invariance of the OHS and OKS was supported across the English, Dutch, Danish, and French versions, with multiple group-confirmatory factor analyses model fit within predefined acceptable limits, supporting cross-comparison of the different language versions of these instruments.
Background and purpose: National hip fracture registries in Denmark, Norway, and Sweden collect extensive pre- and post-fracture data. Inspired by the Global Fragility Fracture Network (Global FFN) minimum common dataset, which is not specifically tailored to Nordic healthcare systems, we aimed to evaluate the feasibility of developing a standardized Nordic Hip Fracture Dataset (Nordic-HFD). Methods: We compared 4 Nordic hip fracture registries: the Danish Multidisciplinary Hip Fracture Registry, the Norwegian Hip Fracture Register, the Swedish Fracture Register, and the Swedish Hip Fracture Register (RIKSHÖFT). Variables available in at least 3 registries, including those obtainable through linkage with national health registries, were assessed for definitions and grouped into demographic, surgical, postoperative, complications, and PROM domains. Results: Across registries, 38 variables were identified. The number of variables available in all 4 registries was 11, while 31 were available in at least 3 registries. After quality review, 30 variables were ultimately considered suitable for inclusion in the proposed Nordic-HFD. Demographic variables such as age, sex, fracture type, pathological fracture, laterality, ASA score, surgical variables such as surgical method, date of surgery, time to surgery, and mortality were directly comparable. Variables on mobility, cognitive impairment, complications, and PROMs may require further harmonization. Conclusion: Establishing a Nordic-HFD is feasible using existing national registries’ infrastructures. The remaining challenge is harmonizing variable definitions to specific research questions and future validation studies. A Nordic-HFD would enhance robust cross-country benchmarking and support international initiatives such as the Global FFN.
BACKGROUND AND PURPOSE:We aimed to quantify how provider-related factors are associated with patients' revealed, GP-mediated choice of arthroplasty provider in Norway, expressed as willingness to travel (WTT) in minutes, and to explore how WTT for travel time was modified by patient characteristics. METHODS:This is a national observational cohort study including all publicly funded, elective primary hip and knee arthroplasties in Norway, 2014-2018 (n = 62,676), with linkage to national registries. A mixed logit model was used to analyze choice among providers with different attributes, in both preference and WTT space. Associations between individual-level travel-time preferences and patient characteristics were analyzed with multilevel modelling. RESULTS:Patients accepted substantial additional travel time for several provider attributes. Mean WTT was 156 min (95% confidence interval [CI] 130-182; median 8) for a dedicated elective surgical unit, 70 min (CI 67-72) for a provider within the patient's regional health authority, 16 min (CI 15-17) for above-median surgical volume, 4 min (CI 3-5) for an adult child living near the provider, and 3 min (CI 3-3) for below-median waiting time. WTT for travel time was reduced in patients with high comorbidity (-27%), low education (-33%), and low income (-30%), with graded gradients across categories, and decreased with increasing age. CONCLUSION:Provider attributes were associated with patients' revealed, GP-mediated choice of arthroplasty provider, expressed as clinically interpretable WTT. WTT was lower among older, sicker, and socioeconomically disadvantaged patients, indicating that realized choice is patterned by both modifiable structural features of the healthcare system and patient-level socioeconomic gradients.
BACKGROUND AND PURPOSE:Aseptic loosening is a major cause of revision surgery. The grade of osteoarthritis (OA) may influence tibial implant migration and the risk of aseptic loosening. We aimed to investigate the association between preoperative OA grade and tibial implant migration in cemented and cementless total and unicompartmental knee arthroplasty. METHODS:We performed a retrospective analysis on a prospective clinical cohort of 990 patients (990 knees). Preoperative OA was graded with the Kellgren-Lawrence (KL) scale and categorized as severe (KL 4) or moderate (KL 1-3). Tibial implant migration was measured by radiostereometric analysis (RSA) at 1, 2, and 5 years. The primary outcome was the 1-year mean difference in maximum total point motion (MTPM) between OA groups. The secondary outcome was the difference between groups in the proportion of patients with continuous migration (MTPM > 0.2 mm between years 1 and 2). Analyses were adjusted for age, sex, and body mass index (BMI). RESULTS:610 patients were classified with severe OA, and 380 patients were classified with moderate OA. Mean 1-year MTPM was similar between OA groups. In the cementless cohort (n = 651), continuous migration occurred in 83/360 (23%) of severe OA cases vs 26/195 (13%) of moderate OA cases. Hence, patients with severe OA and a cementless implant had a mean 73% higher risk of continuous migration. In the cemented cohort (n= 339), comparable results for continuous migration were found. CONCLUSION:Mean 1-year MTPM tibial implant migration values were similar across OA groups. However, patients with severe OA who received cementless implants exhibited a higher risk of continuous migration.
BACKGROUND AND PURPOSE:The primary objective was to compare subsidence and retroversion in the first 2 postoperative years of 2 uncemented hip stem designs in primary minimally invasive anterior-supine surgical (MIS-ASI) total hip arthroplasty: a shortened hip stem (Microplasty) and a standard-length stem with reduced distal width (Reduced Distal). Secondary objectives were to compare migration patterns, patient-reported outcome measures (PROMs), clinical and radiological scores, and the occurrence of (serious) adverse events up to 2 years postoperatively. METHODS:50 patients were randomized in this non-blinded, single-surgeon, industry-funded, radiostereometric analysis study (RSA) (ClinicalTrials.gov NCT03409666). Stem migration was measured relative to directly postoperative at 6 weeks, 1 year, and 2 years postoperatively, using model-based RSA. Linear mixed-effect modelling was used to compare migration. Primary outcomes were subsidence and retroversion at 2 years postoperatively. Secondary outcomes were migration, PROM questionnaires, clinical and radiological scores, and the presence of adverse events in the first 2 postoperative years. RESULTS:Migration of 15 Microplasty and 20 Reduced Distal stems showed comparable initial migration between direct and 6 weeks postoperative RSA, stabilizing thereafter. Predominant migration directions were subsidence and retroversion with mean values at 2 years of 1.47 mm (95% confidence interval [CI] 0.32-2.61) and 2.57° (CI 1.64-3.50) for the Microplasty stem and 2.35 mm (CI 1.36-3.34) and 1.59° (CI 0.79-2.39) for the Reduced Distal stem. At 6 weeks postoperatively, posterior tilt about the medial-lateral axis was different between stem designs, with 0.07° (CI -0.27 to 0.40) for the Microplasty and 0.48° (CI 0.19-0.77) for the Reduced Distal designs. Secondary outcomes were not clinically different between the stem designs. CONCLUSION:We showed that initial subsidence and retroversion for both stem designs in MIS-ASI surgery was present, although likely not clinically relevant. There was no statistically significant difference in subsidence and retroversion between the stem designs. Although initial migration varied substantially between patients and the Reduced Distal design showed more posterior tilting, both designs maintained a stable position from 6 weeks to 2 years postoperatively.
Meniscal preservation is a cornerstone of anterior cruciate ligament reconstruction (ACLR), reflecting the meniscus’ critical role in joint homeostasis and long-term knee health. Concomitant meniscal injuries are common and increasingly managed with repair rather than resection. This educational review summarizes current strategies for the most frequent acute meniscal tears encountered during ACLR. Contemporary practice favors repair whenever feasible, supported by evidence linking meniscal preservation to improved outcomes and reduced osteoarthritis risk. Lateral meniscus posterior root tears are commonly managed with transtibial or anchor-based repair. Ramp lesions require systematic inspection and selective repair, with both all-inside and suture-based techniques yielding favorable results. Bucket-handle tears are repaired using all-inside, inside-out, or combined approaches depending on tear location, with high survival rates when performed alongside ACLR. Radial tears, particularly in vascular zones, should be repaired to restore hoop stress, although optimal suture configurations remain debated. Successful outcomes rely on mechanically stable repairs, individualized rehabilitation, knee stability and alignment, and a supportive biological environment.
Background and purpose: The wear performance of femoral head taper connections is important for the longevity of total hip replacement. Metal release may cause adverse tissue reactions. There are some clinical indications that long neck heads may show increased wear, but no laboratory tests have been published. We aimed to examine the wear performance of femoral head taper connections in long and extra-long neck heads. Methods: Load frame and hip joint simulator wear tests were performed with the same stem designs as in the reference study. The CoCr and zirconia toughened alumina (ZTA) heads of 36 mm diameter were of the long or extra-long neck type. Optical and scanning electron microscopy were utilized to study wear marks, and mass spectrometry to estimate Ti and Co release. Head disassembly forces were measured. Results: Our preclinical, design-specific results showed that, compared with medium necks, long and especially extra-long necks led to increased wear while maintaining an asymmetric wear pattern more widely distributed throughout the contact area. In the hip joint simulator tests, 1 neck fracture occurred. Conclusion: The long and extra-long head taper connections showed increased wear compared with that of medium heads. Although no serious damage occurred, CoCr head tapers were the most affected compared with ZTA.
Background and purpose: Hip fracture treatment with (hemi)arthroplasty carries a risk of periprosthetic joint infection (PJI), which may be reduced by using dual antibiotic-loaded bone cement (ALBC). We aimed to compare the rate of all-cause revision, revision for infection, and mortality following single or dual ALBC use in hip fracture arthroplasty. Methods: From the Dutch Arthroplasty Register, we identified all cemented hemiarthroplasties (HA) and total hip arthroplasties (THA) performed in the period 2007–2024 for proximal femoral fracture. Crude cumulative incidences of all-cause and infection revision were estimated using competing risk survival analyses with death as competing event. Mortality was estimated using Kaplan–Meier analysis. Cause-specific Cox regression models adjusting for age, year of surgery, history of previous surgeries, and American Society of Anesthesiologists (ASA) classification estimated hazard ratios (HRs). Results: We analyzed 56,434 hip arthroplasties, of which 1,651 used dual ALBC. 1-year crude cumulative incidences were similar across groups for all-cause revision, infection revision, and mortality. After adjustment, dual ALBC was not associated with a reduced rate of all-cause revision (HR 1.2, 95% confidence interval [CI] 0.9–1.5]) compared with single ALBC. Dual ALBC was associated with a modestly higher revision for infection (HR 1.6, CI 1.0–2.5) and mortality in HA (HR 1.2, CI 1.1–1.2). Conclusion: Dual ALBC was not associated with lower revision rates compared with single ALBC but a modestly higher revision rate was noted for infection and mortality following hip arthroplasty after hip fracture.
Background and purpose: Periprosthetic bone may influence the longevity of joint implants. We aimed to investigate the association between bone mineral density (BMD) and tibial implant migration of cemented and cementless knee arthroplasty as a surrogate marker of aseptic loosening. Methods: In a prospective cohort study, patients were operated on between 2014 and 2018 with a unicompartmental knee arthroplasty (UKA) or a total knee arthroplasty (TKA). Preoperative BMD was measured using dual-energy X-ray absorptiometry of the lumbar spine and hips. Patients were categorized into low or normal T-score groups (threshold: T-score ≤ –1.0). Postoperative tibial implant migration was assessed using radiostereometry at baseline and 1-, 2-, and 5-year follow-ups. The primary outcome was 1-year maximum total point motion (MTPM) differences between T-score groups. Secondary outcomes evaluated the association between continuous migration (MTPM > 0.2 mm between 1 and 2 years) and T-score. Results: 397 patients were included, where 210 patients received a cementless implant (TKA = 78, UKA = 132) and 187 received a cemented implant (TKA = 83, UKA =104). Estimated 1-year mean MTPM differences between the low and normal T-score groups were 0.15 mm (CI −0.25 to 0.55) for cementless TKA, 0.12 mm (CI −0.25 to 0.49) for cemented TKA, −0.21 mm (CI −0.51 to 0.10) for cementless UKA, and −0.15 mm (CI −0.34 to 0.04) for cemented UKA. A 1-unit increase in T-score showed comparable odds of continuous migration within both cemented (OR 0.94, CI 0.68–1.30) and cementless (OR 0.79, CI 0.56–1.12) tibial implants. Conclusion: Tibial implant migration was not significantly different between patients with low and normal BMD as defined by T-score groups. These findings should be interpreted cautiously due to small group sizes and wide confidence intervals, highlighting the need for further studies to clarify the role of BMD in implant migration.
Background and purpose: Primary traumatic anterior shoulder dislocations are common and can have long-term personal implications for quality of life and the use of the arm for occupational activities and sport participation. A patient care pathway has been reported to contribute to improved quality of care and a reduction in re-dislocations. We developed clinical practice guidelines intended to provide healthcare professionals with an updated pathway for the optimal diagnosis and management of traumatic primary anterior shoulder dislocations. Methods: The clinical practice guidelines were developed by a multidisciplinary committee for the following topics: (i) diagnostic evaluation, (ii) reduction technique, (iii) pain management during reduction, (iv) immobilization, (v) physical therapy, (vi) risk factors for recurrent dislocation, and (vii) primary surgical shoulder stabilization. Results: On admission, dislocations require prompt treatment after diagnostic imaging. The choice of reduction technique is based on individual experience, favoring a biomechanical approach without analgesics. If reduction fails, procedural sedation and analgesia are recommended. To confirm reduction and rule out complications, imaging is repeated, and 1 week of relative immobilization is initiated. Following the acute phase, physical therapy targets early restoration of function, coordination, and proprioception. Risk factors of recurrence include young age and male sex, and surgical intervention may be discussed in the case of age < 40 years, contact athletes, and significant bone loss. The recommendations given are mostly based on data of low GRADE evidence, supplemented with expert opinion. Conclusion: These guidelines emphasize the importance of timely, efficient, and safe management in the emergency department. Pre- and post-reduction diagnostics are crucial for safe reduction and appropriate management. In the case of complications or recurrent instability, timely management enhances long-term outcomes.
BACKGROUND AND PURPOSE:We aimed to compare the effect of 2 femoral stem designs on periprosthetic bone mineral density (BMD) after total hip arthroplasty in a randomized controlled trial. We hypothesized that a short collum-fixated stem (Primoris) would better preserve proximal BMD than a conventional metaphyseal-fixated and diaphyseal engaging stem (Echo). METHODS:61 patients with primary osteoarthritis were randomized to receive either the Primoris (n = 31) or Echo (n = 30) uncemented femoral stem. DXA scans were performed preoperatively, at 6 weeks, 12 months, and 24 months. The prespecified primary outcome was periprosthetic BMD at 24 months and patient-reported outcomes (EQ-5D, Oxford Hip Score, FJS-12) were collected preoperatively, and at each follow-up were secondary. RESULTS:At 24 months, model-based estimates showed significantly higher BMD in the Primoris group than in the Echo group in Gruen zones 3 (mean difference 0.40 g/cm², 95% confidence interval [CI] 0.26-0.53; P < 0.001), 5 (0.20 g/cm², CI 0.07-0.33; P = 0.003), and 7 (0.27 g/cm², CI 0.14-0.41; P < 0.001). These differences corresponded to relative differences of +19.1%, +9.1%, and +14.3%, respectively, compared with the Echo group. In addition, the increase in BMD from 6 weeks to 24 months was significantly greater in the Primoris group in Gruen zone 7 (mean difference in change 0.18 g/cm², CI 0.04-0.32; P = 0.01). PROMs improved similarly in both groups, with no statistically significant between-group differences. CONCLUSION:At 2 years, the collum-fixated Primoris stem preserved more proximal femoral bone than the Echo stem, while PROMs were comparable between groups. The observed preservation of proximal bone stock may be advantageous for long-term bone maintenance and future revision surgery.
Background and purpose: Distal ulnar fractures (DUFs) remain under-investigated, primarily due to limited statistical power resulting from the low incidence. The present classification systems are difficult to use and are not validated for new radiological methods such as cone beam computed tomography (CBCT). We aimed to analyze the reliability and reproducibility of the 2 classification systems, Arbeitsgemeinschaft für Osteosynthesefragen foundation/Orthopaedic Trauma Association (AO/OTA) and Biyani, for fractures of the distal ulnar head and neck using CBCT images.Methods: 76 patients with DUF who underwent a CBCT scan during the years 2016–2022 were included retrospectively. The CBCT images were reviewed twice by 6 observers of different medical specialties and levels of experience. All fractures were classified according to AO/OTA and Biyani. The reliability and reproducibility of each classification system were analyzed using kappa value analysis.Results: The reliability was fair to moderate for AO/OTA, Light’s ĸ 0.41 (95% confidence interval [CI] 0.38–0.45) and moderate for Biyani, Light’s ĸ 0.45 (CI 0.42–0.49), and the reproducibility was substantial for both AO/OTA, mean ĸ 0.65 (CI 0.49–0.80), and Biyani, ĸ 0.69 (CI 0.60–0.79).Conclusion: Both existing classification systems were perceived to be difficult to use and do not match existing fracture patterns. Using CBCT images, they both showed substantial reproducibility but not satisfactory reliability for clinical use.
BACKGROUND AND PURPOSE:Optimal treatment for slipped capital femoral epiphysis (SCFE) has been controversial for decades. Capital realignment surgery (predominant technique: modified Dunn) is a technique to restore anatomy, but it is associated with varying risks of avascular necrosis (AVN) of the femoral head. The aim of our study was to describe outcomes following capital realignment for severe SCFE in a nationwide cohort. METHODS:A longitudinal, nationwide, retrospective cohort study of SCFE patients treated with capital realignment between 2009 and 2021 was conducted, with radiographic and clinical follow-up 2-15 years after surgery. Primary radiographic outcome was AVN. Clinical outcomes were assessed using patient-reported outcome measures (the Copenhagen Hip and Groin Outcome Score [HAGOS] and the 12-item International Hip Outcome Tool [iHOT12]). RESULTS:28 patients were included but 1 patient declined radiographic follow-up. 6/27 (22%, 95% confidence interval [CI] 11-41), developed AVN: 2/19 patients with stable SCFE and 4/8 patients with unstable SCFE. None of the 8 cases in which epiphyseal perfusion was monitored intraoperatively developed AVN. The median total HAGOS and iHOT12 scores were 77 (CI 56-94) and 76 (CI 72-88), respectively. When capital realignment was performed as primary treatment (< 1 month from diagnosis), the corresponding scores were 91 (CI 70-98) and 88 (CI 73-98). CONCLUSION:The overall AVN rate was 22%. Our findings suggest that capital realignment should be reserved for stable SCFE and performed as primary treatment, with intraoperative epiphyseal perfusion monitoring.
BACKGROUND AND PURPOSE:Radiostereometric analysis (RSA) is the reference standard for migration analysis, but adoption is limited by invasive marker implantation and specialized equipment. We developed an automated, surface-based CT-RSA (asCTRSA) method that reports a registration quality measure (mean rigid-body fitting error, ME). Our aim was to evaluate the precision by comparing asCTRSA with marker-based RSA and CT-based Micromotion Analysis (CTMA, v25.1). METHODS:Precision was assessed in a retrospective, repeated-measures, zero-migration study using a porcine cadaver tibial implant scanned in 7 positions (21 double examinations). Migration was reported as maximum total point motion (MTPM) for RSA and asCTRSA. CTMA provided maximum total translation (mTT) as an estimate of MTPM. Mean rigid-body fitting error (ME) was calculated for RSA and asCTRSA (acceptability threshold 0.35 mm). The minimal important difference for MTPM/mTT was 0.1 mm. asCTRSA was applied to 1 clinical case with known migration 3 and 8 months postoperatively (NCT04017533). RESULTS:In the porcine study, precision was 0.09 mm (95% confidence interval [CI] 0.02-0.18) for asCTRSA, 0.08 mm (CI 0.03-0.12) for CTMA, and 0.45 mm (CI 0.20-0.69) for RSA. In the clinical case, asCTRSA detected increasing migration (MTPM 2.5-3.6 mm) and exceeded CTMA's mTT by 0.4 mm at 8 months. Mean rigid-body fitting error remained below 0.35 mm. CONCLUSION:We showed that asCTRSA enables automated, surface-based CT-RSA and demonstrated higher precision than RSA in this zero-migration cadaver setting.
