Purpose The purpose of this study was to investigate the association between post-operative lateral soft tissue laxity and clinical outcomes in robotic-assisted bicruciate-stabilized (BCS) total knee arthroplasty (TKA). Methods A total of 133 knees that underwent primary robotic-assisted BCS TKA were retrospectively analyzed. Intra-operative gaps were measured under a consistent distraction force of 160 N with only the femoral trial components in place. Post-operative lateral soft tissue laxity, defined as the angle formed between the distal femoral and proximal tibial joint lines under varus stress, was measured. The Knee Society Score (KSS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), Forgotten Joint Score-12 (FJS-12), and patient satisfaction were evaluated. Factors associated with post-operative lateral soft tissue laxity were also investigated. Results Knees were classified into three groups according to post-operative lateral soft tissue laxity: mild (<5°; n = 51), moderate (5–7°; n = 46), and severe (>7°; n = 36). The moderate group demonstrated significantly higher KSS scores than the severe group and better WOMAC, FJS-12, and patient satisfaction scores than the mild group. In the moderate group, the intra-operative lateral gap was 2.9 ± 1.9 mm in extension and 5.9 ± 1.3 mm in flexion. Pre-operative alignment and intra-operative lateral gaps were associated with post-operative lateral soft tissue laxity. Conclusions In robotic-assisted BCS TKA, moderate post-operative lateral soft tissue laxity (5–7°) was associated with more favorable clinical outcomes. Careful management of intra-operative lateral gaps may contribute to achieving post-operative lateral soft tissue laxity associated with favorable clinical outcomes.
Purpose The aim of this study was to compare the midterm clinical and radiographic outcomes of total hip arthroplasty (THA) using the Tri-Lock Bone Preservation Stem (BPS) and the ACTIS fully hydroxyapatite (HA)-coated short-tapered stem. Methods A retrospective cohort of 155 consecutive THA patients (76 Tri-Lock BPS, 79 ACTIS stem) was analyzed. After 1:1 propensity score matching, 140 patients (70 pairs) with comparable demographic data were evaluated. The minimum clinical and radiographic follow-up period was 5 years (mean 5.6 years). Harris Hip Scores (HHSs) were compared between groups. Radiographic assessments included stress shielding, spot welds, and cortical hypertrophy according to Gruen zones and Dorr classification. Results No significant differences in pre- or post-operative HHSs were observed between groups. The Tri-Lock BPS group showed significantly more second-grade stress shielding and a higher overall incidence. In Dorr type B cases, Tri-Lock BPS demonstrated more second-grade and total stress shielding. Spot welds in Gruen zones 2 and 6 were more frequent in Tri-Lock BPS, whereas those in zones 4 and 5 were more frequent in ACTIS stem. Cortical hypertrophy in Gruen zone 3 and the total number of lesions were also higher in Tri-Lock BPS. Conclusions The ACTIS fully HA-coated short-tapered stem yielded clinical outcomes comparable with those of the Tri-Lock BPS while demonstrating fewer adverse femoral bone reactions, including stress shielding and cortical hypertrophy.
Purpose Medial unicompartmental knee arthroplasty (UKA) is widely used for isolated medial osteoarthritis, but progression of lateral compartment osteoarthritis remains a common cause of revision. Pre-operative lateral meniscal degeneration on magnetic resonance imaging (MRI) is therefore often considered a potential contraindication. It was hypothesized that such lesions would not impair short-term outcomes after fixed-bearing medial UKA. Methods In this retrospective cohort study, 112 knees in 98 patients (mean age, 72.7 years) who underwent primary fixed-bearing medial UKA with at least 1 year of follow-up were retrospectively reviewed. Hip–knee–ankle (HKA) angle, range of motion (ROM), and 2011 Knee Society Score (KSS) were assessed pre-operatively and at 1 year post-operatively. Pre-operative MRI was used to evaluate the lateral meniscus based on the Mink classification. Knees were divided into two groups: normal and degeneration. Outcomes were compared using the unpaired t test and χ2 test. Adverse events, including revision and infection, were recorded. Results There were 41 knees in the normal group and 71 in the degeneration group. No significant differences were observed in pre-operative HKA angle, ROM, or 2011 KSS scores. Post-operative HKA angle, ROM, and 2011 KSS scores improved significantly, and improvement scores did not differ significantly between the two groups. No revisions or serious adverse events occurred. Conclusions Pre-operative lateral meniscal degeneration did not adversely affect patient-reported outcomes, ROM, or radiographic findings during the first post-operative year following fixed-bearing medial UKA. Longer-term follow-up studies are required to determine whether these findings remain valid over time.
Purpose This study aimed to determine the prevalence of magnetic resonance imaging (MRI) findings suggestive of lateral hinge fracture (LHF), including occult lesions undetectable on conventional imaging, after open-wedge distal tibial tuberosity osteotomy (OWDTO), and to evaluate their clinical significance. Methods This single-center observational study included 47 knees that underwent OWDTO. Imaging assessments consisted of plain radiographs obtained immediately post-operatively and at 1 week and 1 month; computed tomography (CT) at 1 week and 2 months; and MRI at 1 month post-operatively. LHF detection was evaluated for each imaging modality. The morphological pattern of MRI findings was classified using the Takeuchi classification, and bone healing status was assessed using CT at 2 months post-operatively. Factors associated with delayed union were analyzed. Results LHF was detected in 1/47 knees (2.1%) on immediate post-operative radiographs, 2/47 knees (4.3%) both on radiographs and CT at 1 week, 4/47 knees (8.5%) on radiographs at 1 month, and 6/47 knees (12.8%) on CT at 2 months. In contrast, MRI at 1 month identified findings suggestive of LHF in all cases (47/47 knees, 100%). Of these, 46 knees (97.9%) were classified as type I and 1 knee (2.1%) as type III, with no type II findings. Most cases with MRI findings suggestive of occult LHF achieved bone union without clinical complications. Delayed union was instead associated with a larger opening width and with an overt LHF that was already evident on radiographs and CT at 1 week post-operatively. Conclusions MRI findings suggestive of LHF were identified in all cases after OWDTO, and many cases previously considered fracture free on conventional imaging may harbor occult structural changes detectable only by MRI. Most cases with MRI findings suggestive of LHF healed uneventfully, suggesting that the mere presence of an occult LHF does not necessarily indicate a clinically significant problem. Whether MRI offers additional clinical value, particularly for the early detection of clinically important Takeuchi type II and type III fractures, remains to be confirmed, as such fractures were rare or absent in this cohort.
Purpose Osteonecrosis of the femoral head (ONFH) often necessitates total hip arthroplasty (THA). This study compared clinical outcomes and quality of life (QOL) between patients with ONFH and osteoarthritis (OA) undergoing THA. Methods Among 558 hips with ≥2-year follow-up, with 30 hips per group were selected after propensity score matching based on age and sex. Outcomes were assessed preoperatively and at 6 months, 1 year, and 2 years postoperatively using the Oxford Hip Score (OHS), Japanese Orthopaedic Association (JOA) score, Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire, and the Short Form-12 Health Survey version 2 (SF-12v2). Results Both groups demonstrated significant postoperative improvements over time. OHS improved substantially after THA, with no significant differences in postoperative recovery trajectories between groups. Similarly, JOA Scores significantly improved in both groups, with no significant group effect or group-by-time interaction. Significant improvements over time were also observed in JHEQ and SF-12v2 scores. Although no statistically significant group-by-time interaction was observed, the SF-12v2 role component summary score showed a trend toward a group-by-time interaction (p = 0.08). Conclusions Longitudinal analyses demonstrated that patients with ONFH achieved postoperative clinical and patient-reported outcomes comparable to those of patients with OA during the first 2 years after THA. These findings suggest that THA provides similarly favorable recovery irrespective of disease etiology.
Purpose: Subchondral bone fragility contributes to disease progression in knee osteoarthritis (KOA), particularly in osteoporosis. Teriparatide improves subchondral bone quality and shows disease-modifying effects in pre-clinical KOA models, but its clinical efficacy remains unclear. This study assessed the feasibility and variability of teriparatide treatment and explored whether teriparatide may suppress radiographic progression in osteoporotic KOA. Methods: This pilot randomized controlled trial (RCT) enrolled women aged >= 60 years with primary osteoporosis and symptomatic KOA. Participants were randomized to weekly teriparatide (56.5 mu g subcutaneously) or daily active vitamin D (VD) for 24 months. Co-primary outcomes were changes in joint space width (JSW) and bone trabecular integrity (BTI) on radiographs. Feasibility was assessed by retention, adherence, and adverse events, and variability by measurement deviation and reliability. Analyses followed the intention-to-treat principle. Results: Thirteen participants were enrolled (teriparatide, n = 7; VD, n = 6). One participant in each group withdrew within 6 months. One participant in the teriparatide group discontinued after a single dose owing to nausea. Severe adverse events occurred in three patients in the teriparatide group and one in the VD group, none considered related to the intervention. Intra- and inter-rater intraclass correlation coefficients were all >0.9 for the primary outcomes. JSW change at 24 months was smaller in the teriparatide group than in the VD group (-14.8 +/- 11.2% vs. -48.0 +/- 24.3%). BTI changes were -0.7 +/- 16.7% in the teriparatide group and 11.3 +/- 8.2% in the VD group. Conclusions: This pilot RCT demonstrated acceptable feasibility and variability of teriparatide treatment, and exploratory findings suggested smaller JSW narrowing with teriparatide, providing preliminary data to inform future RCTs.
Purpose: Femoral neck fractures (FNFs) are common among elderly patients, and bipolar hemiarthroplasty (BHA) is widely performed in Japan. This nationwide, multicenter, prospective study assessed clinical and radiological outcomes following BHA using representative cemented and cementless stems. Methods: The Japanese Outcome in Neck Fracture (JOIN) study prospectively enrolled 951 patients who underwent primary BHA at 32 institutions between August 2015 and March 2019. Of these, 722 patients (mean age 81.3 f 7.9 years; 78.4% female) with a mean follow-up of 1.1 f 1.0 years were analyzed. Cemented Exeter stems were used in 244 patients, while cementless Accolade II stems were used in 478 patients. Outcomes assessed included peri-operative complications, death, revision surgery, Japanese Orthopaedic Association (JOA) hip score, EuroQol measures (EQ-5D and EQ-VAS), and radiographic findings. Results: Complication rates were low, with femoral fractures occurring in 0.7% of patients, dislocation in 0.6%, and infection in 0.6%. Two patients required stem revision. One year mortality was 4.4% and cumulative mortality at final follow-up was 7.8%, with no significant difference between fixation types. The EQ-5D utility score improved from 0.62 f 0.38 pre-injury to 0.72 f 0.20 at follow-up, whereas the JOA hip score showed a modest decline from 88.7 f 15.8 to 76.7 f 17.4. Radiographs demonstrated stable fixation in all but one case. Conclusions: BHA for FNF demonstrated favorable short-term outcomes with low complication, revision, and mortality rates. Although hip function declined modestly from pre-injury levels, patient-reported quality of life was maintained or improved. Both cemented and cementless BHA remain viable options for elderly patients with FNF. Clinical trial registration number: UMIN000019328.
Purpose Post-operative thigh swelling is a common concern following total hip arthroplasty (THA), potentially impeding early recovery, especially after the direct anterior approach (DAA). This study aimed to quantify the time course of thigh swelling after DAA THA and to evaluate the efficacy of a specialized compression supporter in mitigating it. Methods This single-center retrospective comparative study involved 141 patients who underwent primary unilateral DAA THA. An intervention group (n = 77) wore a proximal thigh compression supporter for 5 days post-operatively, while a control group (n = 64) received no compression. The primary outcome was change in thigh circumference. Secondary outcomes included patient-reported pain and swelling, hip range of motion, and functional scores, measured pre-operatively and at post-operative day 1 (POD1), POD5, 2 weeks, and 12 weeks. Results All patients in the intervention group completed the 5 day wear protocol without any dropouts. In the control group, thigh circumference peaked at POD5, increasing to 106.9 ± 4.1% of the pre-operative baseline before returning to baseline by 12 weeks. The supporter group had a significantly suppressed trajectory of swelling over time compared with the control group (interaction p < 0.001), with significantly less swelling at both POD1 and POD5. At POD5, the intervention group also reported lower pain scores (median numeric rating scale 4.0 vs. 5.0; p < 0.01) and less subjective swelling (p = 0.01). Furthermore, they achieved superior hip flexion at 2 weeks (104° vs. 100°; p < 0.01). By 12 weeks, clinical outcomes were comparable between groups. No compression-related complications occurred. Conclusion A targeted proximal thigh compression supporter effectively reduces early post-operative swelling and patient distress after DAA THA during the first 5 days. This simple, non-invasive intervention may enhance the quality of the patient’s early recovery experience. These findings warrant confirmation through future prospective, randomized trials.
Purpose This study aimed to evaluate the relationship between post-operative knee adduction moment (KAM) and patient-reported outcome measures (PROMs) after medial opening wedge high tibial osteotomy (MOWHTO). Methods A retrospective analysis was conducted on 40 patients who underwent MOWHTO. Radiographic assessments, including hip-knee-ankle angle, were performed pre-operatively and 6 months post-operatively. Dynamic three-dimensional gait analysis was conducted pre-operatively and at 6 months to measure KAM 1st peak. PROMs were evaluated using the WOMAC total score pre-operatively and at 12 months. Pearson correlation analysis examined the relationship between post-operative KAM 1st peak and Delta WOMAC total score. Receiver operating characteristic (ROC) analysis was performed as an exploratory analysis to assess the relationship with the minimal clinically important difference (MCID). Results KAM 1st peak significantly decreased by 53% post-operatively (p < 0.001). A significant positive correlation was observed between post-operative KAM 1st peak and Delta WOMAC total score (r = 0.325, p = 0.020). Exploratory ROC analysis suggested a potential threshold of 25.7 Nm for achieving the MCID. Conclusions While reducing KAM is a primary goal of MOWHTO, excessively low post-operative KAM values may be associated with reduced improvements in PROMs. These findings suggest that achieving an optimal range of correction, rather than simply minimizing KAM, may be important for optimizing post-operative outcomes and highlight the potential value of incorporating dynamic biomechanical assessment.
Purpose Adequate post-operative pain control is essential for recovery after total knee arthroplasty (TKA). Periarticular multimodal drug injection (PMDI) and femoral nerve block (FNB) are commonly used. Although continuous FNB provides effective analgesia, it may impair quadriceps strength and increase the risk of delayed recovery and post-operative falls. This study evaluated the effects of different analgesic strategies on functional recovery and falls after TKA. Methods This retrospective cohort study included 183 patients undergoing unilateral primary TKA. Patients were divided into three groups: PMDI alone (PMDI group, n = 54); continuous FNB combined with PMDI (cFNB group, n = 79); and single-shot FNB combined with PMDI (sFNB group, n = 50). All patients followed a standardized rehabilitation protocol from post-operative day 1. Outcomes included pain scores, opioid consumption, fall events, time to walking with a cane, hospital stay, and functional outcomes at discharge. Results Time to walking with a cane was significantly longer in the cFNB group (p = 0.01). No differences were observed in discharge outcomes or hospital stay. The cFNB group had lower pain scores on post-operative day 1, with a higher proportion achieving Numerical Rating Scale for pain ≤ 2 (p = 0.042). Falls were more frequent in the cFNB group (10.1%), although not statistically significant (p = 0.094), and most occurred within 2 days. Conclusions Continuous FNB improves early analgesia but may delay gait recovery and increase early post-operative fall risk. Careful post-operative monitoring and fall prevention strategies are recommended when continuous FNB is used.
Purpose: The aim of this study was to determine whether poly-L-lactic acid (PLLA) screw fixation is associated with fixation-related complications after transposition osteotomy of the acetabulum (TOA). Methods: A total of 616 patients (800 hips) with hip dysplasia who underwent TOA between 1998 and 2019 were retrospectively reviewed. Acetabular fixation was performed using metal screws in 405 hips and PLLA screws in 395 hips. Surgery-related complications, fixation-related osseous complications, and re-operation were compared between groups. A subanalysis was performed according to greater trochanter fixation material. Logistic regression analysis was used to identify factors associated with acetabular fragment osseous complications among hips treated with PLLA acetabular fixation. Results: Any surgery-related complication was more frequent in the PLLA group than in the metal group (10% vs. 3.5%; p < 0.001). Fixation-related osseous complications (6.3% vs. 1.2%; p < 0.001), acetabular fragment osseous complications (2.0% vs. 0%; p = 0.003), and re-operation for fixation-related osseous complications (3.0% vs. 0.5%; p = 0.006) were also more frequent in the PLLA group. Greater trochanter PLLA fixation was associated with higher rates of greater trochanter-related complications than metal fixation (20% vs. 1.6%; p < 0.001). Among hips treated with PLLA acetabular fixation, male hips, higher body mass index, and lower lateral center-edge angle were independently associated with acetabular fragment osseous complications. Conclusions: Absorbable screw fixation was associated with increased fixation-related complications after TOA. Metal fixation should be considered for acetabular fixation in mechanically demanding hips, and single-screw PLLA fixation without supplemental wire is not recommended for greater trochanter reattachment.
Purpose Cementless total knee arthroplasty (TKA) avoids cement-related complications and has demonstrated high implant survival rates. However, post-operative periprosthetic bone resorption may increase the risk of implant migration. The aim of this study was to compare periprosthetic radiographic bone density changes between cruciate-retaining (CR) and posterior-stabilized (PS) cementless TKA. Methods A total of 62 knees that underwent cementless TKA between June 2017 and December 2023 were retrospectively analyzed. Post-operative range of motion (ROM) and 2011 Knee Society Score (KSS) were evaluated and compared between the CR and PS groups. Periprosthetic radiographic bone density around the tibial component was assessed by measuring the intensity of five predefined regions of interest (ROIs) on radiographic images using ImageJ software immediately after surgery and at 6 and 12 months post-operatively. Results Of the 62 knees, 32 received the CR design and 30 received the PS design. There were no significant differences in post-operative ROM or 2011 KSS between the CR and PS groups. At 12 months, the PS group had significantly lower relative brightness values in all ROIs compared with the CR group (p < 0.05). Multiple regression analysis revealed that only implant design influenced periprosthetic radiographic bone density loss across all ROIs. Conclusion Compared with CR cementless TKA, PS cementless TKA was associated with greater periprosthetic radiographic bone density loss. These findings suggest that careful pre-operative assessment of bone mineral density and long-term monitoring may be particularly important when considering cementless PS fixation.
Purpose: The impact of hyperlipidemia on post-operative outcomes in orthopedic surgery remains unclear, particularly in total knee arthroplasty (TKA). This study aimed to evaluate the association between hyperlipidemia and in-hospital complications following TKA in a Japanese population. Methods: A retrospective nationwide cohort study was conducted using Japan's national Diagnosis Procedure Combination database, including 228,595 patients who underwent TKA between April 2016 and March 2023. Hyperlipidemia was identified using ICD-10 codes E78.0–E78.5. One-to-one propensity score (PS) matching was performed, adjusting for age, sex, body mass index, type of anesthesia, Charlson comorbidity index, and comorbidities. Post-operative complications were compared between patients with and without hyperlipidemia. Given the large sample size in the analysis, the significance level was set at p< 0.001. Result: After PS matching, each group included 45,049 patients. The incidence of deep vein thrombosis (DVT) was 11.2% in the hyperlipidemia group versus 9.8% in the control group [odds ratio (OR) 1.16, 95% confidence interval (CI) 1.11–1.21; p< 0.0001). Surgical site infection (SSI) occurred in 1.6% of hyperlipidemia patients compared with 1.3% without hyperlipidemia (OR 1.23, 95% CI 1.10–1.37; p= 0.0002). Pulmonary embolism showed a non-significant trend (OR 1.37, 95% CI 1.10–1.71; p= 0.005). Conclusions: Hyperlipidemia was associated with an increased risk of DVT and SSI following TKA. Although the absolute differences were modest, these findings suggest that hyperlipidemia may be associated with peri-operative risk profiles in patients undergoing TKA.
Purpose The aim of this study was to identify biopsychosocial factor combinations associated with an unacceptable Knee injury and Osteoarthritis Outcome Score (KOOS) pain state in patients with knee osteoarthritis (KOA) awaiting knee arthroplasty. Methods This cross-sectional study included consecutive patients with radiographic KOA scheduled for knee arthroplasty at a secondary care hospital in Japan (October 2024 to January 2026). Eligible patients had unilateral KOA (Kellgren–Lawrence grade ≥2) and were ambulatory without a walker (cane permitted). Major exclusions included bilateral KOA, inflammatory arthritis, osteonecrosis-related arthroplasty, and revision surgery. The primary outcome (consequent) was an unacceptable KOOS pain state (KOOS pain <73.6). Other dichotomized biopsychosocial and functional variables were treated as antecedents. Association rule mining (apriori algorithm; R, arules) identified multi-factor patterns. Rules were extracted using prespecified thresholds (support ≥0.10, confidence ≥80%, lift ≥1.10) with 95% bootstrap confidence intervals (1000 resamples) and evaluated using contingency table testing (Fisher’s exact test or χ2 test). Result The algorithm generated 6060 candidate rules; 5 single-antecedent and 68 two-antecedent rules met extraction thresholds, and 28 two-antecedent rules differed between applicable and non-applicable groups. Representative high-confidence combined patterns included fear of movement plus depressive symptoms (support 39/101, confidence 100%, lift 1.16; p = 0.001) and unacceptable KOOS symptoms plus fear of movement (support 38/101, confidence 100%, lift 1.16; p = 0.002). Conclusions In patients with end-stage KOA awaiting arthroplasty, unacceptable pain clustered with greater symptom burden and psychosocial distress. These findings support combined screening to inform risk stratification and integrated care planning. Considering this study is exploratory and cross-sectional, causality cannot be inferred, and generalizability beyond surgical candidates may be limited.
Purpose This study investigated the impact of surgical approach on the incidence of deep vein thrombosis (DVT) following total hip arthroplasty (THA). Methods This retrospective single-center study investigated 1675 consecutive patients who underwent primary unilateral THA. Patients were divided according to the surgical approach into anterolateral supine (ALS; n = 408), direct lateral (DL; n = 629), and posterolateral (PL; n = 638) groups. Each surgical approach was performed by a single, highly experienced, high-volume surgeon according to their personal preference. Doppler ultrasound was performed in all patients 1 month before and 7 days after surgery to detect DVT in the lower extremities. Result The PL group had the lowest Japanese Orthopaedic Association scores and the longest operation times (both p < 0.001). Post-operative C-reactive protein was lowest in the ALS group (p < 0.001). The frequency of post-operative DVT was 4.6% in the ALS group, 7.9% in the DL group, and 10.7% in the PL group (p = 0.003). Multiple logistic regression analysis identified the following risk factors for DVT following THA: age [odds ratio (OR) 1.05, 95% confidence interval (CI) 1.03–1.08), body mass index (OR 1.06, 95% CI 1.03–1.12), D-dimer (OR 1.06, 95% CI 1.02–1.10), and PL approach (vs. ALS approach, OR 4.62, 95% CI 2.20–9.70; vs. DL approach, OR 2.82, 95% CI 1.40–5.68). Conclusions Although various factors influence the occurrence of DVT, the ALS approach may potentially reduce the post-operative inflammatory response and contribute to a decrease in the occurrence of post-operative DVT.
Purpose The Oxford Hip Score (OHS) is a patient-reported outcome measure (PROM) used to evaluate hip pain and function in patients treated with total hip arthroplasty (THA). Given the clinical utility and interpretability limitations of other hip-related PROMs, further scale assessment is warranted. The purpose of this study was to examine the structural validity of the OHS in patients undergoing THA. Methods Data were obtained from the Surgical Outcomes System registry. Structural validity of the 12-item OHS was assessed using contemporary confirmatory factor analysis methods. As model fit criteria were not satisfied, exploratory factor analysis (EFA) was performed to identify a more parsimonious model. As model fit criteria were met, multigroup invariance testing was assessed across sex (males/females) and age groups (≤44, 45–54, 55–64, 65–74, and ≥75 years). Results Neither the one-factor [comparative fit index (CFI) = 0.92, standardized root mean square residual (SRMR) = 0.05, Tucker–Lewis index (TLI) = 0.90, Bollen's incremental fit index (IFI) = 0.92, root mean square error of approximation (RMSEA) = 0.09] nor the two-factor (CFI = 0.94, SRMR = 0.04, TLI = 0.92, IFI = 0.94, RMSEA = 0.080) 12-item OHS met all recommended model fit indices. As such, EFA procedures identified a four-item short-form version with substantially improved model fit (CFI = 0.99, TLI = 0.98, RMSEA = 0.06, SRMR = 0.015). Measurement invariance was supported across sex and age subgroups. Conclusion This study identified lack of scale validity of the original OHS at the pre-operative visit, indicating that this scale should not be used in its current form in clinical practice. However, subsequent analysis identified a modified short-form version with improved model fit and considered invariant across patients of different sexes and age groups. Prior to its use, further research is warranted in patients undergoing THA.
Purpose The aim of this study was to validate the safety and reliability of a lateral short-axis ultrasound-guided intra-articular hip injection (IAHI) technique using magnetic resonance arthrography (MRA). Methods A retrospective review was conducted of 273 hips that underwent ultrasound-guided IAHI followed by MRA between May 2012 and October 2023. All injections were performed using a lateral short-axis image parallel technique with the hip in slight flexion and internal rotation. Successful intra-articular injection was assessed based on contrast distribution on axial MRA. Contrast patterns were classified descriptively, and intra- and interobserver reliability were evaluated using Cohen's κ statistic. Procedure-related complications were recorded. Results The cohort included 148 women and 125 men with a mean age of 40.3 ± 14.1 years. Successful intra-articular contrast enhancement was achieved in 271 of 273 hips (99.3%). Contrast distribution was graded as excellent in 195 hips (71.4%), good in 70 (25.6%), fair in 6 (2.2%), and poor in 2 (0.7%). No infections occurred. One transient femoral nerve palsy resolved within several hours. Intra- and interobserver agreement for contrast assessment was substantial (κ = 0.60–0.73). Conclusions The lateral short-axis ultrasound-guided hip injection technique provides a safe and highly reliable method for intra-articular access, as validated by MRA in a large clinical cohort, and demonstrates acceptable reproducibility for diagnostic hip injections.
Background Outcomes after total knee arthroplasty (TKA) are commonly assessed using patient-reported outcome measures (PROMs). How these measures align with objective performance-based outcomes remains uncertain. This study evaluated the longitudinal association between multiple PROM domains and the Timed Up & Go (TUG) test. Methods Seventy-one patients aged ≥65 years who underwent unilateral TKA were assessed using the 2011 Knee Society Score [symptoms (SYM), patient satisfaction (PS), and functional activity (FA)], the Forgotten Joint Score-12 (FJS-12), the 25-questin Geriatric Locomotive Function Scale (GLFS-25), and the TUG test before surgery and at 6 months, 1 year, and 3 years post-operatively. Changes over time and correlations between PROMs and TUG were analyzed with repeated measures analysis of variance and simple linear regression analysis. Results All scores significantly improved at 6 months post-TKA, with no significant changes thereafter. FA and GLFS-25 showed low to moderate correlations with TUG across time points (FA: r = −0.42, −0.57, −0.55, −0.62; GLFS-25: r = 0.42, 0.51, 0.53, 0.56). SYM, PS, and FJS-12 demonstrated weaker or non-significant correlations (SYM, before: r = −0.26; PS, before: r = −0.37; 1 year: r = −0.24; FJS-12, 6 months: r = −0.31; 3 years: r = −0.28). Both FA and GLFS-25 demonstrated significantly stronger correlations with the TUG test than SYM, PS, and FJS-12. Conclusions FA and GLFS-25 demonstrated a relatively stronger correlation with the TUG test. However, overall correlations between TUG and PROMs were low to moderate. Self-reported measures did not necessarily align with recovery of lower limb function, indicating that combining PROMs with the TUG test may provide a more comprehensive assessment after TKA.
Purpose: In medial opening wedge high tibial osteotomy (OWHTO) with distal tibial tubercle osteotomy (DTO), the transverse osteotomy is typically made perpendicular to the tibial axis in the sagittal plane to avoid posterior gap behind the tibial tubercle. However, directing the osteotomy toward the fibular head may place the osteotomy line too close to the tibial articular surface. The purpose of this study was to investigate the relationship between fibular height on intra-operative fluoroscopy, the true fibular–articular distance, and the transverse osteotomy–articular distance. Methods: Seventy-five patients (92 knees) who underwent OWHTO with DTO were evaluated retrospectively. Medial and lateral posterior tibial slopes (mPTS and lPTS) were measured on pre-operative computed tomography (CT) scans. On sagittal CT images, the anterior and posterior distances from the fibular head to the articular surface of the lateral tibial plateau (AD and PD) were measured, and their difference (AD-PD) was used as a surrogate for fibular height on fluoroscopy. On post-operative CT scans, the minimum distance from the transverse osteotomy line to the articular surface (TO-A) was measured. Correlations among these parameters were analyzed. Result: The mean AD, PD, AD-PD, and TO-A was 13.1 ± 2.2 mm, 9.5 ± 2.3 mm, 3.6 ± 1.9 mm, and 15.5 ± 3.0 mm, respectively. TO-A correlated positively with PD and negatively with AD-PD. PD and TO-A correlated negatively, and AD-PD correlated positively with both mPTS and lPTS. Linear regression analysis showed that lPTS was a predictor of TO-A. Conclusions: In patients with steep posterior tibial slope, the transverse osteotomy in OWHTO with DTO may be closer to the articular surface than expected, even when the fibular head appears low on fluoroscopy. Surgeons should therefore avoid placing the osteotomy too close to the articular surface in such cases.
Purpose: The aim of this study was to investigate the influence of alignment and joint line correction on soft tissue balance after functionally aligned (FA) robotic arm-assisted cruciate-retaining (CR) total knee arthroplasty (TKA). Methods: This retrospective analysis included 59 patients who underwent unilateral FA CR-TKA. Knee phenotypes, including joint line obliquity (JLO) and arithmetic hip–knee–ankle angle (aHKA), and an intra-operative surgical plan using a robotic system were examined. The joint component gap balance at extension and flexion was measured using an offset-type tensor after insertion of the femoral trial components, and the correlations between gap balance and knee phenotypes were statistically evaluated. Correlations between gap balance and clinical outcomes were also evaluated. Result: The aHKA and its correction were positively correlated with extension gap balance, but not with flexion gap balance. The tibial JLO correction angles were positively correlated with extension gap balance. The tibial lateral bone resection thickness was positively correlated with the extension gap balance and the tibial JLO correction angle. Flexion gap balance was not correlated with tibial JLO correction angle or external rotational angle relative to the femoral posterior condylar axis, and the two factors were positively correlated with each other. No significant correlations were found between clinical outcomes and gap balance. Conclusions: Tibial JLO correction and tibial lateral bone resection thickness were associated with extension gap balance in FA CR-TKA. Knee phenotypes and tibial resection thickness should be considered when surgeons attempt to balance the extension gap in CR-TKA.
