Background: After total knee arthroplasty (TKA), patients have limited knee range of motion (ROM), trophic changes and pain. Cryotherapy and compression are recommended in the literature, but no study has shown that cryotherapy and compression combined leads to better results than cryotherapy alone. The primary objective was to compare knee ROM after 21 days of rehabilitation post-TKA between patients who underwent rehabilitation with compressive cryotherapy with those who had cryotherapy alone. The secondary objectives were to compare other trophic, pain and functional outcomes. Methods: Forty patients were randomized into two groups: Standard Cryotherapy (SC = 20, median age 77 years), which applied cold packs along with their rehabilitation; and Compressive Cryotherapy (CC = 20, median age 76 years), which received cold compression. Knee joint’s passive and active ROM (primary outcome) were measured with a goniometer. Knee’s circumference, fluctuation test, pain at rest and during activity, 6-minute walking test (6MWT) and KOOS questionnaire were secondary outcomes. The groups were compared on D1 (baseline) and D21 of rehabilitation. A survival analysis has compared the groups on D1, D8, D15, D21. Results: All subjects had a significant improvement in all the parameters on D21 relative to D1 (p < .05), except for pain at rest (p = .065 for CC and p = .052 for SC). On D21, the CC group had a significantly larger improvement in the joint effusion (p = .002), pain during activity (p = .005), 6MWT (p = .018) and KOOS (p = .004) than the SC group. Based on the survival analysis, the CC group had significantly faster improvement in the joint ROM (p = .011 for flexion and p = .038 for extension) and knee circumference (p = .013) than the SC group. Conclusions: Both cryotherapy methods improved joint ROM, trophic changes, pain and function. Adding dynamic compression to a cryotherapy protocol provided further benefits: a significantly faster improvement in passive knee flexion ROM, a greater reduction of swelling, and pain during activity. Similarly, walking distance and KOOS questionnaire were significantly better for CC. Trials registration: The study was registered in the ClinicalTrials.gov database on 14/09/2023 (identifier: NCT06037824).

Several tools exist to measure tightness of the gastrocnemius muscles; however, few of them are reliable enough to be used routinely in the clinic. The primary objective of this study was to evaluate the intra- and inter-rater reliability of a new equinometer. The secondary objective was to determine the load to apply on the plantar surface of the metatarsal heads to achieve the highest reliability when measuring gastrocnemius tightness. The equinometer consisted of a goniometer and an electronic dynamometer, hooked up to a computer. Three raters carried out three trials of passive dorsiflexion by applying controlled pressure to the metatarsal heads of both ankles in 29 healthy subjects under two experimental conditions: knee extended (KE) and knee flexed at 30 degrees (KF). The equinometer continuously recorded the ankle dorsiflexion values (in °) corresponding to each 1 N interval of plantar pressure between 4 N and 20 N. The intra- and inter-rater reliability of the ankle dorsiflexion were evaluated through the intra-class correlation (ICC) coefficients in each of the pressure intervals. The intra-rater ICC in KE and KF was between 0.84 and 0.98. The inter-rater ICC in KE and KF was between 0.59 and 0.92. The pressure interval between 14 N and 15 N had the highest intra-rater (ICC = 1) and inter-rater reliability (0.87≤ICC≤0.99). A more refined analysis of this interval found that a load of 14.5 N yielded the best reliability. This compact equinometer has excellent intra-rater reliability and moderate to good inter-rater reliability. Since this reliability is optimal in the 14–15 N range, this load should be used going forward in clinical practice, especially when aiming to define a pathological threshold for tightness of the gastrocnemius muscles.

Background: Isolated gastrocnemius tightness (IGT) is a prevalent condition linked to various foot pathologies. In a previous quantitative gait analysis study, we identified an increase in knee flexion during the midstance phase in IGT patients compared with controls. Although stretching and eccentric exercises (the Stanish protocol) are commonly used for IGT management, their impact on gait parameters remains poorly understood. This study aimed to assess the influence of a Stanish protocol on gait parameters in bilateral IGT subjects. Methods: We enrolled 10 asymptomatic bilateral IGT subjects and 10 controls. Quantitative gait analysis and dynamic baropodometry were carried out on each subject. A Stanish protocol was applied for 4 weeks (five sessions/week) by the IGT group, followed by a similar gait analysis. The ankle and knee range of motion and foot pressure distribution were assessed during the midstance phase of the gait. Results: An increase in knee flexion was initially present in the IGT group compared with controls (8.9 +/− 4.6 vs. 3.4 +/− 2.3 degrees, p < 0.001). There was no difference in the ankle range of motion and foot pressures between the groups at that time. Significant reductions in knee flexion during gait were observed in the IGT subjects after the Stanish protocol (8.9 +/− 4.6 to 3.7 +/− 2.3 degrees, p < 0.001) with a normalization of this parameter (3.4 +/− 2.3 in controls vs. 3.7 +/− 2.3 degrees in IGT, p = 0.72). There was no change in ankle range of motion and foot pressure after the Stanish protocol. Conclusions: Our findings support the effectiveness of the Stanish protocol in reducing knee flexion and normalizing gait in IGT subjects. This protocol not only offers a noninvasive approach for IGT-related issues management but could also enable prophylactic care in asymptomatic cases.

Accurate estimation of hip joint center (HJC) position is crucial during gait analysis. HJC is obtained with predictive or functional methods. But in the functional method, there is no consensus on where to place the skin markers and which combination to use. The objective of this study was to analyze how different combinations of skin markers affect the estimation of HJC position relative to predictive methods. Forty-one healthy volunteers were included in this study; thirteen markers were placed on the pelvis and hip of each subject’s lower limbs. Various marker combinations were used to determine the HJC position based on ten calibration movement trials, captured by a motion capture system. The estimated HJC position for each combination was evaluated by focusing on the range and standard deviation of the mean norm values of HJC and the mean X, Y, Z coordinates of HJC for each limb. The combinations that produced the best estimates incorporated the markers on the pelvis and on proximal and easily identifiable muscles, with results close to predictive methods. The combination that excluded the markers on the pelvis was not robust in estimating the HJC position.

Background: Lateralization of the glenoid implant improves functional outcomes in Reverse Shoulder Arthroplasty. Lateralization does not appear to impact the Deltoid’s Moment Arm. Therefore, the stabilizing effect described in the literature would not be the result of an increase this moment arm. A static biomechanical model, derived from Magnetic Resonance Imaging, can be used to assess the coaptation effect of the Middle Deltoid. The objective of this study was to analyze the impact of increasing amounts of glenoid lateralization on the moment arm but also on its coaptation effect. Methods: Eight patients (72.6 ± 6.5 years) operated for Reverse Shoulder Arthroplasty were included in the study. Three-dimensional models of each shoulder were created based on imaging taken at 6 months postoperative. A least square sphere representing the prosthetic implant was added to each 3D models. A static biomechanical model was then applied to different planar portions of the Middle Deltoid (from 3D models), first without lateralization and then with simulated lateralization of 6, 9 and 12mm. This static model enables to compute a Coaptation/Elevation Ratio and to measure the Deltoid’s Moment Arm. The inter- and intra-rater agreement of the 3D models was evaluated. Results: One patient was excluded due to motion during imaging. The inter- and intra-rater agreement was over 0.99. The ratio increased starting at 6 mm of lateralization (p<0.05), compared to the initial position. The moment arm was not affected by lateralization (p<0.05), except in two slices starting at 9 mm (S1 p<0.05 and S2 p<0.05). Conclusion: Our hypothesis that the Middle Deltoid’s coaptation role would be greater with glenosphere lateralization was confirmed. This trend was not found in the moment arm, which showed little sensitivity to lateralization. The stabilizing effect therefore appears to stem from the coaptation role of the Middle Deltoid.

L'Arthroplastie Totale de Hanche est l'intervention orthopédique la plus pratiquée au monde. Elle s'adresse aujourd'hui à des sujets plus jeunes sur indication de coxarthrose primitive principalement. L'avènement des abords mini-invasifs a modifié la prise en charge postopératoire et la rééducation. Néanmoins une altération des paramètres stabilométriques et des lésions musculaires mises en évidence à l'IRM persistent en postopératoire. Dans ce travail de thèse, nous avons montré dans un premier temps qu'une rééducation menée soit sur plateforme de stabilométrie soit en auto-rééducation à domicile normalisait ces paramètres stabilométriques après une voie postérieure à J45-J60 postopératoire. Nous avons ensuite mis en évidence la persistance d'altérations de certains paramètres d'Analyse Quantifiée de la Marche chez des patients à un an postopératoire d'une Arthroplastie Totale de Hanche par voies Antérieure et Antéro-Latérale. Ces résultats apportent ainsi de nouveaux éléments en faveur d'une rééducation adaptée en postopératoire d'une Arthroplastie Totale de Hanche. Enfin, avec l'ambition de rendre l'examen d'Analyse Quantifiée de la Marche plus compatible au contexte orthopédique, nous avons évalué l'influence du positionnement des marqueurs cutanés et leurs combinaisons sur l'estimation du Centre Articulaire de la Hanche via la méthode fonctionnelle par rapport aux méthodes prédictives classiques (Plug-in-Gait et Harrington).