Nik Žlak

Objective: To compare patient-reported outcomes and reintervention rates after open vs arthroscopic fusion of the ankle (TT—tibiotalar) or subtalar (ST) joint over a 10-year period in a cohort of patients from a single center. Methods: In total, 129 patients (142 joints) underwent surgery for isolated TT or ST osteoarthritis between 2010 and 2020: 40 TT fusions (11 arthroscopic, 29 open) and 102 ST fusions (25 arthroscopic, 77 open). The course of treatment was followed clinically using patient-reported outcome measures (PROMs) for ankle function: Foot and Ankle Outcome Score—FAOS, general quality of life (European Quality of Life in Five Dimensions 3-level time-trade-off—EQ-5D 3L-TTO) and activity level (Tegner Activity Scale—TAS), and by tracking revision procedures. Results: The median follow-up time was 8 (3–13) years. The mean age at the time of surgery was 52 (14) years. Most subjective scores showed significant improvement; cumulative FAOS improved from 41 to 57 in the TT group and from 41 to 67 in the ST group and EQ-5D from 0.40 to 0.55 (TT group) and from 0.38 to 0.60 (ST group), while TAS remained at 2. The ST fusion patients had better subjective outcomes than TT fusion patients. There were no significant differences in PROMs between arthroscopic and open procedures. Older age and preoperative FAOS pain were found to be negative predictors for the postoperative FAOS subscales. Overall, there was an 18% revision rate: 17 non-unions and 8 infections. In addition, 20 hardware removals were performed. Conclusion: Isolated TT or ST fusions performed open or arthroscopically were safe and significantly improved function and quality of life and reduced joint-related pain but did not increase patients’ activity levels. Patients with ST fusion had a better subjective outcome. Older age and lower preoperative FAOS pain were associated with a worse postoperative subjective outcome. Level of Evidence: Level III

Background: We present prospective short-term results of a limited patient series treated with two innovative partial ankle arthroplasties: talar dome resurfacing for mild-to-moderate ankle osteoarthritis and talar shoulder hemiarthroplasty for chronic medial osteochondral lesions of the talus. Methods: Eleven patients underwent talus resurfacing and six patients had talar hemiarthroplasty. The outcome was followed by patient-reported measures and by pursuing serious adverse events or implant failures over a 2-year period. Progression of ankle osteoarthritis, peri-implant bone changes, and implant migration were followed radiographically. Results: Active dorsiflexion increased from 3° to 10° in resurfacing and from 15° to 22° in hemiarthroplasty. Patient-reported ankle function, quality of life, and activity level tended to improve only slightly after resurfacing (cumulative Foot and Ankle Outcome Score, from 41 to 42; Foot and Ankle Ability Measures for daily activities [FAAM-ADL], from 43 to 46; EQ-5D-3L time trade-off, from 0.38 to 0.39; Tegner activity scale score, from 1.6 to 2.0) but moderately after hemiarthroplasty (cumulative Foot and Ankle Outcome Score, from 58 to 68; FAAM-ADL, from 37 to 71; EQ-5D-3L time trade-off, from 0.53 to 0.72; Tegner activity scale score, from 3.1 to 3.1). No implant-related radiographic changes, implant failures, or implant-related revision surgeries were recorded. Conclusions: Based on a small and heterogeneous prospective case series, both partial ankle implants investigated were safe and stable over 2-year follow-up, without any radiographic osteoarthritis progression of the remaining joint. However, patient-reported ankle function, quality of life, and activity level showed a tendency toward only minor improvement after resurfacing but a moderate increase after hemiarthroplasty.

Background: To investigate the influence of sport-specific activities on coronal axial alignment of the lower limbs in adolescent football and ice hockey players. Methods: This cross-sectional study targeted healthy adolescent male football and ice hockey players with at least 3 years of sports participation. 90 football and 38 ice hockey players aged 12–16 years were divided into five age-matched subgroups. Coronal alignment of the lower limbs was determined by measuring the players' intercondylar or intermalleolar (ICD-IMD) distance with a custom-made calliper. In addition, their sports history was recorded. An age-matched comparison between the two sports groups was performed using the two-way model ANOVA and a multiple regression model for ICD-IMD was constructed. Results were additionally compared with age-matched data from the general population published in recent literature. Results: A statistically significant increase in ICD-IMD values (p < 0.05) was found between 12 (football 0 mm; ice hockey − 64 mm) and 16 years (football 340 mm; ice hockey 310 mm) in both sports groups. Results of regression analysis of pooled group data showed that ICD-IMD has low positive correlation (r = 0.407; r² = 0.168; p < 0.05) with time of participation in sport, but no association with age of athletes at the start of their sport participation (r = − 0.018; r² = 0.000; p > 0.05). There were no statistically significant differences between the two groups at any time point. Both sports groups showed a significant increase in ICD-IMD values (mean 198 mm) after the age of 14 compared to the general population. Conclusions: Participation in football and ice hockey is associated with a similar increase in ICD-IMD in the adolescent years in male athletes. The observed increase was higher in both groups of athletes than in their peers who do not regularly participate in sports. Level of Evidence: Level 4 (case series).

Purpose: To evaluate predicting factors for patient‐reported outcomes and revision interventions following surgical treatment of patients with patellofemoral instability.Methods: From a prospective database at the university Orthopedic Department, 138 knees from 116 patients who underwent patellofemoral instability surgery (2012–2019) were enrolled in a retrospective analysis: 34 cases of isolated MPFLrec; 92 cases of MPFLrec plus tibial tuberosity transfer; and 12 cases of MPFLrec plus trochleoplasty. Patient‐reported outcome measures were recorded for knee‐specific function (KOOS), general quality of life (EQ‐5D), and activity level (Tegner scale). Post‐operative revision interventions were also actively recorded. As potential predicting factors, patient demographic (gender, age, BMI) and radiographic (pre‐operative: patellar height and tilt, tibial tuberosity–trochlear groove distance, trochlear dysplasia, knee osteoarthritis; post‐operative: MPFL insertion point; intra‐operative: isolated vs. combined procedures, chondropenia severity score) parameters were analyzed using multivariate linear regression models.Results: With median follow‐up of 4.4 (1.0–8.9) years, all patient‐reported outcome measures had significantly improved from pre‐operative levels: KOOS cumulative, from 71 (15) to 78 (16); EQ‐5D, from 0.68 (0.20) to 0.78 (0.21); and Tegner activity scale, from 3 (0–10) to 4 (0–10). No patellofemoral instability revision procedures were performed. One‐fifth (27/138) of the operated knees required second surgical interventions, predominately due to hardware or arthrofibrosis. Patients who required post‐operative knee manipulation under anesthesia or arthroscopic debridement showed lower post‐operative improvement for KOOS cumulative and EQ‐5D. Age, BMI, patellofemoral knee osteoarthritis, and shorter follow‐up time revealed significant negative correlations to some of the post‐operative KOOS subscales. Age was negatively correlated to post‐operative EQ‐5D, while post‐operative Tegner activity scale was negatively correlated to female gender and patellofemoral chondropenia severity score. Femoral MPFL insertion point revealed no association with any outcome measures.Conclusion: Patellofemoral instability surgery for isolated or combined MPFLrec is safe and substantially improves knee function and patient quality of life and activity levels. Serious adverse events are rare, with no recurrent patellofemoral instability. Patients who required post‐operative knee manipulation or arthroscopic debridement showed less improvement in subjective measures of treatment outcomes. Older age, higher BMI, worse pre‐operative patellofemoral cartilage status, and female gender had negative effects on outcome.Level of evidence: III.

This study assessed the influence of a 10‐day hypoxic bed rest on cartilage biomarkers and subchondral bone density across the patellofemoral joint (PFJ). Within clinical settings hypoxic tissue may arise in several types of disorders. Furthermore, a hypoxic environment is being considered for space flight habitats in the near future. Female participants (N = 12) participated in this study comprising three 10‐day interventions: hypoxic ambulation (HAMB), normoxic bed rest (NBR), and hypoxic bed rest (HBR). Venous samples were collected prior to (day −2: Pre) and during the intervention (days 2 and 5), immediately before reambulation (D11) and 24 hr post intervention (R1). Blood samples were analyzed for: aggrecan, hyaluronan, Type IIA procollagen amino terminal propeptide (PIIANP), and cartilage oligomeric matrix protein (COMP). Total bone mineral density (BMD) in eight regions (2 mm × 10 mm) across the PFJ was determined. The three interventions (HAMB, HBR, and NBR) did not induce any significant changes in the cartilage biomarkers of hyaluronan or PIIANP. Aggrecan increased during the HAMB trial to 2.02 fold the Pre value. COMP decreased significantly in both NBR & HBR compared to HAMB on D5. There were significant differences in BMD measured across the PFJ from cortical patellar bone (735 to 800 mg/cm³) to femur trabecular (195 to 226 mg/cm³). However, there were no significant changes in BMD from Pre to Post bed rest. These results indicate that there were no significant detectable effects of inactivity/unloading on subchondral bone density. The biomarker of cartilage, COMP, decreased on D5, whereas the addition of hypoxia to bed rest had no effect, it appears that hypoxia in combination with ambulation counteracted this decrease.