Carlos De la Fuente

BACKGROUND: Clinically, muscle strength and neuromuscular function are expected to return toward normal levels within 12 months after surgical repair of Achilles tendon rupture (rATR). However, the recovery of muscle fiber conduc-tion velocity (MFCV) as a muscle fiber property remains unclear. Thus, we aimed to determine whether MFCV and maximal voluntary isometric contraction (MVIC) of the plantar-flexors are restored 12 months after rATR compared with healthy individuals. AIM: Thus, we aimed to determine whether MFCV and MVIC of the plantar-flexors are restored 12 months after rATR compared with healthy individuals. METHODS: A total of 20 participants (10 men with rATR and 10 healthy controls) were included in this cross-sectional study. Medial gastrocnemius MFCV at 40% and 60% of MVIC was measured using a 16-channel linear electro-myography array to be compared between groups using mixed-model repeated-measures ANOVA. Plantar-flexion MVIC was compared using a one-tailed Mann-Whitney U test. Alpha error was set to 0.05. RESULTS: The Achilles group showed higher MFCV at 60% compared to 40% of MVIC (4.7±1.2 vs 4.2±1.1 ms-1; p=0.020), whereas the control group did not (4.0±0.3 vs 3.6±0.7 ms-1; p=0.120). The Achilles group exhibited higher MFCV than controls at both 40% (4.2±1.1 vs 3.6±0.7 ms-1; p=0.040) and 60% MVIC (4.7±1.2 vs 4.0±0.3 ms-1; p=0.010). The Achilles group exhibited lower MVIC than controls (1.5±0.6 vs 2.1±0.5 Nmkg-1; p=0.033). INTERPRETATION: Neuromuscular function and strength are not normalized one-year after rATR. Patients generate plantar-flexion strength with higher MFCV than healthy individuals.

Although some studies have shown an agreement between near-infrared spectroscopy (NIRS) and surface electromyography signals during dynamic exercise for a single muscle, research assessing multiple muscles with different roles is lacking. This would improve understanding of the connection between muscle excitation and muscle oxygen saturation (SmO₂) profiles. Our study evaluated whether muscle excitation aligns with SmO2 during cycling in graded exercise testing. Fifteen cyclists and triathletes (age = 22 ± 6 years, stature = 175 ± 8 cm, training hours = 12 ± 4 hours·week^-1) performed a graded exercise test on a cycle ergometer. NIRS and electromyography devices were placed on the preferred sides of the vastus lateralis, tibialis anterior, gastrocnemius medialis, and biceps femoris. Results showed that, in general, while average root mean square (RMS) increased, SmO₂ decreased (p < 0.05), except in the gastrocnemius medialis, which remained stable. Vastus lateralis and biceps femoris exhibited moderate signal agreement between RMS and SmO₂ (CCCLin: vastus lateralis = 0.70; biceps femoris = 0.50), while stabilizing muscles showed weak agreement (gastrocnemius medialis CCCLin = 0.32; tibialis anterior CCCLin = 0.39). In conclusion, power-generating and stabilizing muscles respond oppositely in SmO₂ and RMS during progressively increasing intensity exercise until exhaustion.

Purpose: Borderline hip dysplasia (BhD) may be associated with insufficient acetabular coverage. Thus, we investigated potential differences in acetabular anatomical measurements derived from computerised tomography (CT) that characterise BhD compared with healthy controls.Methods: BhD patients (lateral centre edge angle [LCEA] between 18° and 25°) and healthy controls (LCEA between 25° and 40°) underwent anteroposterior pelvic X‐ray and CT scans to study the Wiberg and Tönnis angle, the extrusion and Fear indices, notch width and depth, anterior and posterior wall heights, anterior and posterior articular surfaces, articular circumference, the ratio between the anterior articular surface and the articular circumference, the ratio between the posterior articular surface and the articular circumference, and the ratio between the notch width and the articular circumference. Independent two‐tailed t‐tests, Mann–Whitney U tests, and odds ratios were obtained (α = 5%).Results: Twenty‐three BhD patients (aged 31.5 ± 8.3 years and LCEA 21.6° ± 4.0°) and thirty‐one healthy controls (aged 34.1 ± 8.0 years and LCEA 33.7° ± 5.5°) were included. The CT features most sensitive for detecting BhD were the anterior acetabular surface (p < 0.001) and ratios of anterior (p = 0.009), anteroposterior (p = 0.008) and posterior (p < 0.008) acetabular surfaces, as well as acetabular notch width (p = 0.002).Conclusions: CT characterisation showed insufficient acetabular coverage in BhD patients along the superior axis (lower Wiberg angle, and increased Tönnis angle and extrusion index), anterior axis (lower anterior acetabular surface and anteroposterior acetabular surface ratio, and increased posterior acetabular ratio), and inferior axis (increased acetabular notch width). These structural alterations suggest that periacetabular osteotomy may address persistent pathological deformation and stress on soft tissues and cartilage‐bone structures more effectively.Level of Evidence: Diagnostic III.

Objective: To determine whether 448 kHz capacitive-resistive monopolar radiofrequency (CRMR) after platelet-rich-plasma (PRP) injections can further reduce pain sensation within the first 72 h in an active population with patellar chondropathy. Methods: One-hundred fifty-three active patients with patellar chondropathy grade II-III were followed for three days after PRP injections with and without CRMR under a control–placebo study. They were clinically evaluated for pain sensation using a visual analog scale ranging from zero (no pain sensation) to ten (highest pain sensation). Pain sensation was described using medians and analyzed through the Friedman and Conover test for within-group comparison (pre-intervention, and 24, 48, and 72 h post-intervention) and the Mann–Whitney test for between-group comparisons (Intervention vs. Placebo) with α = 5% and 1−β = 80%. Results: The placebo group showed statistical significance between pre-intervention and 24 h (Δ = −2.0 pts, p < 0.001), baseline and 48 h (Δ = −2.0 pts, p < 0.001), baseline and 72 h (Δ = −3.0 pts, p < 0.001), 24 h and 48 h (Δ = 0.0 pts, p < 0.016), and 24 h and 72 h (Δ = −1.0 pts, p < 0.001). The radiofrequency group showed statistical significance between baseline and 24 h (Δ = −7.0 pts, p < 0.001), baseline and 48 h (Δ = −7.0 pts, p < 0.001), baseline and 72 h (Δ = −8.0 pts, p < 0.001), 24 h and 72 h (Δ = −1.0 pts, p < 0.001), and 48 h and 72 h (Δ = −1.0 pts, p < 0.001). The placebo and radiofrequency groups were significantly different at 24 h (Δ = 4.0 pts, p < 0.001), 48 h (Δ = 4.0 pts, p < 0.001), and 72 h (Δ = 4.0 pts, p < 0.001). Conclusions: CRMR therapy administered after knee intra-articular injections of PRP within the first 72 h in active populations with patellar chondropathy reduces pain sensation with a median difference of 8.0 pts compared to baseline and 4.0 pts compared to placebo group.

Summary: Objective: Here, we discuss cumulative fatigue based on volume and power output from 12 professional male cyclists during two consecutive editions of the Giro d’Italia. Methods: Volume and power output were recorded and described according to time at different intensity zones based on power output (Z0 lower to Z7 higher). Correlations, principal component analysis (PCA), Gaussian clustering, and two-way ANOVA were performed (type error I of 5%). Results: The higher intensity zones elicited higher power output in those shorter stages (R ² = 0.54). In contrast, the lower intensity zones were predominant in longer stages. The time spent in Z1 to Z3 (r = 0.67, 0.84, and 0.73) correlated more with stage’s volume duration than time in Z4 to Z7 (r = 0.48, 0.44, and 0.51, and 0.38). The normalized volume declined between stages 2 to 4, 8 to 10, 13 to 15, and 18 to 19. Negative slopes of time spent in Z4 and Z6 occurred one or two stages before Z1 presented negative slopes. In contrast, positive slopes of higher intensity zones were observed with a negative slope of Z1. Different clusters distributions of time volume to complete the grand tour were found (p<0.05). Finally, average power in Z1, Z2, Z3, Z4, Z5, Z6, and Z7 explained 63.62%, 18.20%, 8.12%, 5.84%, 2.98%, 1.20%, and 0.02% of the total variance in the normalized time volume, respectively. Volume and power zone data can recognize cumulative fatigue and performance recovery during a grand tour. Rest days favored the performance recovery, mostly the second rest day.

Background: Borderline hip dysplasia (BhD) might be associated with insufficient acetabular coverage. Thus, we investigated potential differences in acetabular anatomical measurements derived from computerized tomography (CT) that characterize BhD compared with healthy controls. Methods: BhD patients (LCEA between 18º and 25º) and healthy controls (LCEA between 25º and 40º) underwent anteroposterior pelvic X-ray and CT to study Wiberg and Tönnis angle, extrusion and Fear index, notch width and depth, anterior and posterior wall height, anterior and posterior articular surfaces, articular circumference, the ratio between the anterior articular surface and the articular circumference, the ratio between the posterior articular surface and the articular circumference, and the ratio between the notch width and the articular circumference. An independent two-tailed t-test, U of Mann-Whitney test, and odds ratios were obtained (α = 5%). Results: Twenty-three BhD patients aged 31.5 ± 8.3 years and LCEA 21.6° ± 4.0° and thirty-one healthy controls aged 34.1 ± 8.0 years and LCEA 33.7° ± 5.5° were included. The sensitive CT features for BhD were anterior ( p < 0.001) acetabular surface, anterior ( p = 0.009), anteroposterior ( p = 0.008) and posterior ( p < 0.008) acetabular surface ratios, and acetabular notch width ( p = 0.002). Conclusions: BhD CT characterization provides tridimensional anatomical insights beyond the LCEA. BhD insufficient acetabular coverage can be found along the superior (lower Wiberg angle, and increased Tönnis angle and extrusion index), anterior (lower anterior acetabular surface and anteroposterior acetabular surface ratio, and increased posterior acetabular ratio), and inferior (increased acetabular notch width) axis.

The mechanisms behind the persistent Quadriceps weakness observed after an Anterior Cruciate Ligament reconstruction (ACLr) remain debatable. We described the time course of changes in Quadriceps thickness, strength, and thigh circumference over six months following an ACLr. We also studied the causal relation between Quadriceps thickness, total thickness and strength. Quadriceps thicknesses, Quadriceps strength, and thigh circumference were measured preoperative, 3, and 6 months post-ACLr surgery in 103 patients (77 men and 26 women). Limbs and time were compared with repeated-measures ANOVA and causal relations through mediation analysis (α = 5%). From 0 to 3 months post-surgery, Quadriceps strength (p<0.05), and VI (p<0.05) and VL (p<0.001) thicknesses was reduced. From 3 to 6 months, Quadriceps strength (p<0.05), total Quadriceps thickness (p<0.001), and VI (p<0.001) and VL (p<0.05) thicknesses increased. VM and RF thicknesses increase to 3 months after ACLr (p<0.05). Quadriceps strength, circumference at 5 cm, VI, VL, VM, and total Quadriceps thickness remain lower than the contralateral limb 6 months following an ACLr (p<0.05). The VI thickness determine indirectly (p<0.001) through the total Quadriceps thickness the Quadriceps strength pattern, while the VL thickness directly determined it (p=0.034). Quadriceps thickness adapts heterogeneously, with VI and VL atrophying for up to three months, explaining the post-ACLr quadriceps weakness. By 6 months, VI does not recover its thickness proportion, and VI and VL do not return to pre-surgery conditions. Both vastii muscles primarily determine Quadriceps strength changes, eliciting the VI thickness as a key biomarker for Quadriceps weakness following ACLr.

Several conditions may require medial collateral ligament (MCL) surgery, especially when high physical demands are required. Thus, we described a technique for anatomical repair of distal MCL rupture using a distal anchor and MCL augmentation through Achilles tendon allograft with proximal bone block and interference screw. This procedure fixes an anchor distally at the tibia. Then, the ligament endings are sutured using a continuous simple‐type technique. Subsequently, a low‐radiated Achilles tendon allograft is attached proximally and fixed through an interference screw. Finally, the allograft is sutured using a continuous simple‐type technique. Our anatomical MCL repair and augmentation allows a reinforced anatomical technique to control the valgus instability caused by MCL distal ruptures, considering the MCL axial traction and posterior oblique ligament fiber orientations. Technique Video: video See video under supplementary data.

Purpose: To determine whether intra‐articular injections of peripheral blood stem cells (PBSC) with hyaluronan (HA)‐based scaffold improve articular cartilage regeneration in chondral injuries caused by mixed‐femoroacetabular impingement syndrome (FAIS) over a period longer than 24 months post‐hip arthroscopy.Methods: In this prospective cohort study, patients with mixed‐FAIS and chondral injury ≥ IIIB according to the International Cartilage Regeneration and Joint Preservation Society grade or III/IV of Konan/Haddad classification underwent intra‐articular injection of PBSC with an HA‐based scaffold and micro‐drillings during hip arthroscopy. The degree of chondral repair was measured at baseline and 5 years using the International Cartilage Repair Society morphologic score system (MSS) as the primary outcome. Pain was measured at baseline and 5 years using the Visual Analogue Scale for Pain (VAS Pain), and hip functionality was measured at baseline (presurgery), 6 months, 1 year, and 5 years using the Hip Outcome Score (HOS). The largest diameter of injury, median follow‐up, side effects, complications, and improvements were described. T‐test, ANOVA with multiple comparisons, and statistical power were estimated.Results: From initially 34 cases, 25 patients were enrolled. The median follow‐up was 5.1 ± 0.3 years. One patient (4%) reported a few side effects with filgrastim administration. No infection, tumours, or synovitis was reported. The largest diameters in zones two, three, and four were 12.4 ± 3.1 mm (n = 8), 13.5 ± 2.8 mm (n = 14), and 11.4 ± 1.9 mm (n = 3), respectively. Ninety‐two percent (23/25) of patients improved their outcomes. The MSS and HOS increased from 3.8 ± 1.1 to 9.6 ± 1.5 pts (p < 0.001) and from 65.5 ± 13.0 to 93.9 ± 2.4 pts (p < 0.001), respectively. The VAS‐Pain decreased from 5.3 ± 0.7 to 1.3 ± 0.6 mm (p < 0.001). The obtained a posteriori power‐size was 0.99.Conclusion: The intervention suggests a favourable impact on articular cartilage regeneration and clinical outcomes for hip chondral lesions in mixed‐FAIS injuries after a median follow‐up of 5.1 ± 0.3 years.Level of Evidence: Level IV.