Immobilization by 21 days of bed rest results in type II collagen degradation in healthy individuals.

OBJECTIVE: To investigate the effects of 21 days of bed rest immobilization (with and without exercise and nutrition interventions) on type II collagen biomarker concentrations in healthy individuals. DESIGN: Twelve healthy male participants (age 34.2 ± 8.3 years; body mass index 22.4 ± 1.7 kg/m²) were exposed to 6 days ambulatory baseline data collection (BDC), 21 days head-down-tilt bed rest (HDT, CON) + interventions (HDT + resistive vibration exercise (2 times/week, 25 minutes): RVE; HDT + RVE + whey protein (0.6 g/kg body weight/day) and bicarbonate supplementation (90 mmol KHCO3/day: NeX), and 6 days of re-ambulation (R) in a cross-over designed study. The starting HDT condition was randomized (CON-RVE-NEX, RVE-NEX-CON, NEX-CON-RVE). Blood and urine samples were collected before, during, and after HDT. Serum concentrations (s) of CPII, C2C, C1,2C, and urinary concentrations (u) of CTX-II and Coll2-1NO2 were measured. RESULTS: Twenty-one days of HDT resulted in increased sCPII (p < 0.001), sC2C (p < 0.001), and sC1,2C (p = 0.001) (highest increases: sCPII (+24.2% - HDT5), sC2C (+24.4% - HDT7), sC1,2C (+13.5% - HDT2). sC2C remained elevated at R+1 (p = 0.002) and R+6 (p < 0.001) compared to baseline. NeX led to lower sCPII (p < 0.001) and sC1,2C (p = 0.003) compared to CON. uCTX-II (second void and 24-hour urine) increased during HDT (p < 0.001, highest increase on HDT21: second void +82.8% (p < 0.001); 24-hour urine + 77.8% (p < 0.001). NeX resulted in lower uCTX-II concentrations in 24-hour urine (p = 0.012) compared to CON. CONCLUSIONS: Twenty-one days of bed rest immobilization results in type II collagen degradation that does not recover within 6 days of resuming ambulation. The combination of resistive vibration exercise and protein/bicarbonate supplementation minimally counteracted this effect.

Fully automatic algorithm for detecting and tracking anatomical shoulder landmarks on fluoroscopy images with artificial intelligence.

OBJECTIVE: Patients with rotator cuff tears present often with glenohumeral joint instability. Assessing anatomic angles and shoulder kinematics from fluoroscopy requires labelling of specific landmarks in each image. This study aimed to develop an artificial intelligence model for automatic landmark detection from fluoroscopic images for motion tracking of the scapula and humeral head. MATERIALS AND METHODS: Fluoroscopic images were acquired for both shoulders of 25 participants (N = 12 patients with unilateral rotator cuff tear, 6 men, mean (standard deviation) age: 63.7 ± 9.7 years; 13 asymptomatic subjects, 7 men, 58.2 ± 8.9 years) during a 30° arm abduction and adduction movement in the scapular plane with and without handheld weights of 2 and 4 kg. A 3D full-resolution convolutional neural network (nnU-Net) was trained to automatically locate five landmarks (glenohumeral joint centre, humeral shaft, inferior and superior edges of the glenoid and most lateral point of the acromion) and a calibration sphere. RESULTS: The nnU-Net was trained with ground-truth data from 6021 fluoroscopic images of 40 shoulders and tested with 1925 fluoroscopic images of 10 shoulders. The automatic landmark detection algorithm achieved an accuracy above inter-rater variability and slightly below intra-rater variability. All landmarks and the calibration sphere were located within 1.5 mm, except the humeral landmark within 9.6 mm, but differences in abduction angles were within 1°. CONCLUSION: The proposed algorithm detects the desired landmarks on fluoroscopic images with sufficient accuracy and can therefore be applied to automatically assess shoulder motion, scapular rotation or glenohumeral translation in the scapular plane. CLINICAL RELEVANCE STATEMENT: This nnU-net algorithm facilitates efficient and objective identification and tracking of anatomical landmarks on fluoroscopic images necessary for measuring clinically relevant anatomical configuration (e.g. critical shoulder angle) and enables investigation of dynamic glenohumeral joint stability in pathological shoulders. KEY POINTS: • Anatomical configuration and glenohumeral joint stability are often a concern after rotator cuff tears. • Artificial intelligence applied to fluoroscopic images helps to identify and track anatomical landmarks during dynamic movements. • The developed automatic landmark detection algorithm optimised the labelling procedures and is suitable for clinical application.

Severity of rotator cuff disorders and additional load affect fluoroscopy-based shoulder kinematics during arm abduction.

BACKGROUND: Rotator cuff disorders, whether symptomatic or asymptomatic, may result in abnormal shoulder kinematics (scapular rotation and glenohumeral translation). This study aimed to investigate the effect of rotator cuff tears on in vivo shoulder kinematics during a 30° loaded abduction test using single-plane fluoroscopy. MATERIALS AND METHODS: In total, 25 younger controls, 25 older controls and 25 patients with unilateral symptomatic rotator cuff tears participated in this study. Both shoulders of each participant were analysed and grouped on the basis of magnetic resonance imaging into healthy, rotator cuff tendinopathy, asymptomatic and symptomatic rotator cuff tears. All participants performed a bilateral 30° arm abduction and adduction movement in the scapular plane with handheld weights (0, 2 and 4 kg) during fluoroscopy acquisition. The range of upward-downward scapular rotation and superior-inferior glenohumeral translation were measured and analysed during abduction and adduction using a linear mixed model (loads, shoulder types) with random effects (shoulder ID). RESULTS: Scapular rotation was greater in shoulders with rotator cuff tendinopathy and asymptomatic rotator cuff tears than in healthy shoulders. Additional load increased upward during abduction and downward during adduction scapular rotation (P < 0.001 in all groups but rotator cuff tendinopathy). In healthy shoulders, upward scapular rotation during 30° abduction increased from 2.3° with 0-kg load to 4.1° with 4-kg load and on shoulders with symptomatic rotator cuff tears from 3.6° with 0-kg load to 6.5° with 4-kg load. Glenohumeral translation was influenced by the handheld weights only in shoulders with rotator cuff tendinopathy (P ≤ 0.020). Overall, superior glenohumeral translation during 30° abduction was approximately 1.0 mm with all loads. CONCLUSIONS: The results of glenohumeral translation comparable to control but greater scapular rotations during 30° abduction in the scapular plane in rotator cuff tears indicate that the scapula compensates for rotator cuff deficiency by rotating. Further analysis of load-dependent joint stability is needed to better understand glenohumeral and scapula motion. LEVEL OF EVIDENCE: Level 2. TRIAL REGISTRATION: Ethical approval was obtained from the regional ethics committee (Ethics Committee Northwest Switzerland EKNZ 2021-00182), and the study was registered at clinicaltrials.gov on 29 March 2021 (trial registration number NCT04819724, https://clinicaltrials.gov/ct2/show/NCT04819724 ).

Ambulatory knee biomechanics and muscle activity 2 years after ACL surgery: InternalBraceTM-augmented ACL repair versus ACL reconstruction versus healthy controls.

BACKGROUND: Little is known about knee mechanics and muscle control after augmented ACL repair. Our aim was to compare knee biomechanics and leg muscle activity during walking between the legs of patients 2 years after InternalBraceTM-augmented anterior cruciate ligament repair (ACL-IB) and between patients after ACL-IB and ACL reconstruction (ACL-R), and controls. METHODS: Twenty-nine ACL-IB, 27 sex- and age-matched ACL-R (hamstring tendon autograft) and 29 matched controls completed an instrumented gait analysis. Knee joint angles, moments, power, and leg muscle activity were compared between the involved and uninvolved leg in ACL-IB (paired t-tests), and between the involved legs in ACL patients and the non-dominant leg in controls (analysis of variance and posthoc Bonferroni tests) using statistical parametric mapping (SPM, P < 0.05). Means and 95% confidence intervals (CI) of differences in discrete parameters (DP; i.e., maximum/minimum) were calculated. RESULTS: Significant differences were observed in ACL-IB only in minimum knee flexion angle (DP: 2.4°, CI [-4.4;-0.5]; involved > uninvolved) and maximum knee flexion moment during stance (-0.07Nm/kg, CI [-0.13;-0.00]; involved < uninvolved), and differences between ACL-IB and ACL-R only in maximum knee flexion during swing (DP: 3.6°, CI [0.5;7.0]; ACL-IB > ACL-R). Compared to controls, ACL-IB (SPM: 0-3%GC, P = 0.015; 98-100%, P = 0.016; DP: -6.3 mm, CI [-11.7;-0.8]) and ACL-R (DP: -6.0 mm, CI [-11.4;-0.2]) had lower (maximum) anterior tibia position around heel strike. ACL-R also had lower maximum knee extension moment (DP: -0.13Nm/kg, CI [-0.23;-0.02]) and internal knee rotation moment (SPM: 34-41%GC, P < 0.001; DP: -0.03Nm/kg, CI [-0.06;-0.00]) during stance, and greater maximum semitendinosus activity before heel strike (DP: 11.2%maximum voluntary contraction, CI [0.1;21.3]) than controls. CONCLUSION: Our results suggest comparable ambulatory knee function 2 years after ACL-IB and ACL-R, with ACL-IB showing only small differences between legs. However, the differences between both ACL groups and controls suggest that function in the involved leg is not fully recovered and that ACL tear is not only a mechanical disruption but also affects the sensorimotor integrity, which may not be restored after surgery. The trend toward fewer abnormalities in knee moments and semitendinosus muscle function during walking after ACL-IB warrants further investigation and may underscore the importance of preserving the hamstring muscles as ACL agonists. LEVEL OF EVIDENCE: Level III, case-control study. TRIAL REGISTRATION: clinicaltrials.gov, NCT04429165 (12/06/2020).

Test-retest reliability of isometric shoulder muscle strength during abduction and rotation tasks measured using the Biodex dynamometer.

BACKGROUND: The Constant score (CS) is often used clinically to assess shoulder function and includes a muscle strength assessment only for abduction. The aim of this study was to evaluate the test-retest reliability of isometric shoulder muscle strength during various positions of abduction and rotation with the Biodex dynamometer and to determine their correlation with the strength assessment of the CS. METHODS: Ten young healthy subjects participated in this study. Isometric shoulder muscle strength was measured during 3 repetitions for abduction at 10° and 30° abduction in the scapular plane (with extended elbow and hand in neutral position) and for internal and external rotation (with the arm at 15° abduction in the scapular plane and elbow flexed at 90°). Muscle strength tests with the Biodex dynamometer were measured in 2 different sessions. The CS was acquired only in the first session. Intraclass correlation coefficients (ICCs) with 95% confidence interval, limits of agreement, and paired t tests for repeated tests of each abduction and rotation task were calculated. Pearson's correlation between the strength parameter of the CS and isometric muscle strength was investigated. RESULTS: Muscle strength did not differ between tests (P > .05) with good to very good reliabilities for abduction at 10° and 30°, external rotation and internal rotation (ICC >0.7 for all). A moderate correlation of the strength parameter of the CS with all isometric shoulder strength parameters was observed (r > 0.5 for all). CONCLUSION: Shoulder muscle strength for abduction and rotation measured with the Biodex dynamometer are reproducible and correlate with the strength assessment of the CS. Therefore, these isometric muscle strength tests can be further employed to investigate the effect of different shoulder joint pathology on muscle strength. These measurements consider a more comprehensive functionality of the rotator cuff than the single strength evaluation in abduction within the CS as both abduction and rotation are assessed. Potentially, this would allow for a more precise differentiation between the various outcomes of rotator cuff tears.

Modified surgical anchor refixation in older patients with acute proximal hamstring rupture: clinical outcome, patient satisfaction and muscle strength.

INTRODUCTION: After conventional surgical refixation of the hamstrings after proximal hamstring rupture, patients frequently experience pain while sitting and deficits in hamstring muscle strength of the operated side. To improve these outcomes, we have modified the surgical anchor placement and have carried out a thorough follow-up examination. MATERIALS AND METHODS: Thirteen older patients (8 female, 5 males) with a median age of 64.2 (range, 52.1-80.4) years were surgically treated for acute proximal hamstring rupture using modified anchor placement and participated in a follow-up assessment at a median of 46.2 (11.2-75.0) months after surgery. Patients completed the Perth Hamstring Assessment Tool (PHAT), quality of life questionnaire (EQ-5D-5L) and the Lower Extremity Functional Scale (LEFS), and rated their satisfaction level on a scale from 0 to 100%. Local tenderness on the ischial tuberosity and maximum passive hip flexion were measured on both limbs. Maximum isokinetic knee flexor muscle strength was measured bilaterally using a dynamometer. RESULTS: The median (range) PHAT, EQ-5D-5L and LEFS score were 78.8/100 (54.6-99.8), 0.94/1 (0.83-1) and 88.75/100 (61.25-100). The median satisfaction was 100% (90-100%). Only one patient felt discomfort when the ischial tuberosity was palpated. Neither maximum passive hip flexion nor maximum isokinetic flexor muscle strength differed between the operated and non-operated side (P > 0.58). Clinical scores did not correlate with the leg symmetry index of knee flexor muscle strength (Spearman's rho < 0.448, P > 0.125). There were no tendon re-ruptures, or postoperative sciatic radiculopathy, at the time of follow-up. CONCLUSIONS: The modified extra-anatomical anchor placement resulted in good clinical and functional outcome of surgical repair of acute proximal hamstring rupture. Especially the absence of postoperative pain while sitting and the comparable muscle strength to the contralateral side is promising. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04867746, registered.

Distal femoral osteotomy for the valgus knee: indications, complications, clinical and radiological outcome.

INTRODUCTION: The aim of this study was to describe the indications and technical aspects of medial closing and lateral opening distal femoral osteotomy (MCDFO and LODFO) for patients with a valgus knee and to report clinical and radiological outcomes and complications. METHODS: Over 6 years, 28 DFOs (22 MCDFO, 6 LODFO) were performed in 22 Patients. In this cohort study, we retrospectively analyzed clinical and radiological outcome measures as well as complications. RESULTS: The median (range) age was 47 (17-63) years, height 1.68 (1.56-1.98) m, body mass 80 (49-105) kg, and body mass index (BMI) 27.4 (18.6-37.0) kg/m2. The clinical follow-up was 21 (7-81) months, the need for total or unicompartmental knee arthroplasty (TKA/UKA) and hardware removal was followed up for 59 (7-108) months postoperatively. Preoperatively, hip-knee-ankle angle (HKA, negative values denote varus) was 7.0 (2.0-13.0)°, mechanical lateral distal femoral angle (mLDFA) was 83.7 (79.9-88.2)°, and mechanical proximal tibial angle (MPTA) was 89.0 (86.6-94.5)°. Postoperatively, HKA was -1.3 (-9.0-1.2)° and mLDFA was 90.8 (87.3-97.3)°. The incidence of minor and major complications was 25% and 14%, the incidence of delayed and nonunion was 18% and 4%, respectively. At the last follow-up, 18% of the patients had pain at rest, 25% during activities of daily living, and 39% during physical activity, and 71% were satisfied with the outcome. 7% of the cases received a TKA/UKA, 71% received a hardware removal. CONCLUSION: DFO is a reasonable treatment for lateral osteoarthritis in younger patients to avoid disease progression and the need for an UKA/TKA. However, there is a long rehabilitation time, a considerable risk for complications, and a high need for hardware removal. While many patients experienced symptoms at the long-term follow-up, most were satisfied with the outcome. Appropriate patient information is essential. Level of evidence Level IV, Case Series. Trial registration number NCT04382118, clinicaltrials.gov, May 11, 2020.

Functional leg performance 2 years after ACL surgery: a comparison between InternalBrace™-augmented repair versus reconstruction versus healthy controls.

BACKGROUND: While clinical and patient-reported outcomes have been investigated in patients after InternalBrace™-augmented anterior cruciate ligament repair (ACL-IB), less is known regarding restoration of functional performance. We aimed to determine differences in functional performance within and between patients 2 years after ACL-IB, patients 2 years after ACL reconstruction (ACL-R), and healthy controls. MATERIALS AND METHODS: A total of 29 ACL-IB, 27 ACL-R (hamstring autograft), and 29 controls performed single-leg hop (maximum forward distance hop, SLH; side hop > 40 cm in 30 s, SH), proprioception (knee joint position sense at 30° and 60° flexion), and dynamic postural balance (Y Balance) tests. Differences were calculated within groups (side-to-side difference) and between the involved leg of patients and the non-dominant leg of controls, and were evaluated to predefined statistical (P < 0.05), clinically relevant, and methodological (smallest detectable change) thresholds. The number of exceeded thresholds represented no (0), small (1), moderate (2), or strong (3) differences. In addition, the relative number of participants achieving leg symmetry (≥ 90%) and normal performance (≥ 90% of the average performance of the non-dominant leg of controls) were compared between groups (chi-squared tests, P < 0.05). RESULTS: We observed no-to-moderate leg differences within ACL-IB (moderate difference in hops) and within ACL-R (moderate difference in knee proprioception), no leg differences between patient groups, no-to-small leg differences between ACL-IB and controls, and no leg differences between ACL-R and controls in functional performance. However, two patients in ACL-IB and ACL-R, respectively, passed the hop pretest only with their uninvolved leg, and fewer patients after ACL-IB and ACL-R than controls reached a leg symmetry and normal leg performance of controls in SLH (P < 0.001). CONCLUSIONS: Functional performance seems to be comparable 2 years postoperatively between ACL-IB and ACL-R for a specific subgroup of patients (i.e., proximal ACL tears, moderate activity level). However, the presumed advantage of comparable functional outcome with preserved knee structures after augmented ACL repair compared with ACL-R, and the tendency of both patient groups toward leg asymmetry and compromised single-leg hop performance in the involved legs, warrants further investigation. Level of Evidence Level III, case-control study. Trial registration clinicaltrials.gov, NCT04429165 (12/09/2020). Prospectively registered, https://clinicaltrials.gov/ct2/show/NCT04429165 .

Load-induced increase in muscle activity during 30° abduction in patients with rotator cuff tears and control subjects.

BACKGROUND: Rotator cuff muscles stabilise the glenohumeral joint and contribute to the initial abduction phase with other shoulder muscles. This study aimed to determine if the load-induced increase in shoulder muscle activity during a 30° abduction test is influenced by asymptomatic or symptomatic rotator cuff pathologies. MATERIALS AND METHODS: Twenty-five patients with unilateral rotator cuff tears (age, 64.3 ± 10.2 years), 25 older control subjects (55.4 ± 8.2 years) and 25 younger control subjects (26.1 ± 2.3 years) participated in this study. Participants performed a bilateral 30° arm abduction and adduction movement in the scapular plane with handheld weights (0-4 kg). Activity of the deltoid, infraspinatus, biceps brachii, pectoralis major, latissimus dorsi and upper trapezius muscles was analysed at maximum abduction angle after normalisation to maximum voluntary contraction. Shoulders were classified into rotator cuff tendinopathy, asymptomatic and symptomatic rotator cuff tears, and healthy based on magnetic resonance images. A linear mixed model (loads, shoulder types) with random effects (shoulder identification) was applied to the log-transformed muscle activities. RESULTS: Muscle activity increased with increasing load in all muscles and shoulder types (P < 0.001), and 1-kg increments in additional weights were significant (P < 0.001). Significant effects of rotator cuff pathologies were found for all muscles analysed (P < 0.05). In all muscles, activity was at least 20% higher in symptomatic rotator cuff tears than in healthy shoulders (P < 0.001). Symptomatic rotator cuff tears showed 20-32% higher posterior deltoid (P < 0.05) and 19-25% higher pectoralis major (P < 0.01) activity when compared with asymptomatic tears. CONCLUSIONS: Rotator cuff pathologies are associated with greater relative activity of shoulder muscles, even with low levels of additional load. Therefore, the inclusion of loaded shoulder tests in the diagnosis and rehabilitation of rotator cuff pathologies can provide important insight into the functional status of shoulders and can be used to guide treatment decisions. LEVEL OF EVIDENCE: Level 2. TRIAL REGISTRATION: Ethical approval was obtained from the regional ethics committee (Ethics Committee Northwest Switzerland EKNZ 2021-00182), and the study was registered at clinicaltrials.gov on 29 March 2021 (trial registration number NCT04819724, https://clinicaltrials.gov/ct2/show/NCT04819724 ).

Abductor Muscle Strength Deficit in Patients After Total Hip Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: The aims of this study were to assess and quantify hip abductor muscle strength deficits after total hip arthroplasty (THA) and to determine associations with external factors. METHODS: Studies reporting on hip abductor muscle strength before and/or after THA performed for osteoarthritis or atraumatic osteonecrosis of the hip were considered for inclusion. Data sources were Embase, Medline, and the Cochrane Central Register of Controlled Trials. Muscle strength on the affected side was compared with the healthy contralateral side or with control subjects. Study quality was assessed using a modified Newcastle-Ottawa Scale. RESULTS: Nineteen studies reporting on 875 subjects met the inclusion criteria. Patients scheduled for THA had a mean strength deficit of 18.6% (95% confidence interval (CI) [-33.9, -3.2%]) compared with control subjects. Abductor muscle strength then increased by 20.2% (CI [5.6, 34.8%]) at 4-6 months, 29.6% (CI [4.7, 54.4%]) at 9-12 months, and 49.8% (CI [-31.0, 130.6%]) at 18-24 months postoperatively compared with preoperative values. For unilateral THA, the mean torque ratio was 86.3% (CI [75.4, 97.2%]) and 93.4% (CI [75.1, 111.6%]) before and >24 months after THA, respectively. Study quality was low to moderate. CONCLUSION: Hip abductor muscle strength deficits may gradually improve during 24 months after THA possibly without complete recovery. Cautious interpretation of these findings is warranted because high-quality evidence is largely missing.

Assessing Site Specificity of Osteoarthritic Gait Kinematics with Wearable Sensors and Their Association with Patient Reported Outcome Measures (PROMs): Knee versus Hip Osteoarthritis.

There is a great need for quantitative outcomes reflecting the functional status in patients with knee or hip osteoarthritis (OA) to advance the development and investigation of interventions for OA. The purpose of this study was to determine if gait kinematics specific to the disease-i.e., knee versus hip OA-can be identified using wearable sensors and statistical parametric mapping (SPM) and whether disease-related gait deviations are associated with patient reported outcome measures. 113 participants (N = 29 unilateral knee OA; N = 30 unilateral hip OA; N = 54 age-matched asymptomatic persons) completed gait analysis with wearable sensors and the Knee/Hip Osteoarthritis Outcome Score (KOOS/HOOS). Data were analyzed using SPM. Knee and hip kinematics differed between patients with knee OA and patients with hip OA (up to 14°, p < 0.001 for knee and 8°, p = 0.003 for hip kinematics), and differences from controls were more pronounced in the affected than unaffected leg of patients. The observed deviations in ankle, knee and hip kinematic trajectories from controls were associated with KOOS/HOOS in both groups. Capturing gait kinematics using wearables has a large potential for application as outcome in clinical trials and for monitoring treatment success in patients with knee or hip OA and in large cohorts representing a major advancement in research on musculoskeletal diseases.

Lateral trochlear lengthening osteotomy.

INTRODUCTION: The purpose of this study was to describe the indications and technical aspects as well as evaluate the clinical and functional outcome of lengthening osteotomy of the lateral trochlear ridge in patients with patellofemoral pain and/or patella instability and presence of trochlear dysplasia Dejour type A or lack of Dejour type dysplasia and short lateral articular trochlea. MATERIALS AND METHODS: Six consecutive adult patients were treated with a lateral trochlear lengthening osteotomy. Five patients received a concomitant medial patellofemoral ligament reconstruction. Three patients had prior patella stabilization surgeries. Trochlea dysplasia (Dejour classification), Caton-Dechamps index, tibial tubercle trochlear groove (TT-TG) distance, patellar tilt and lateral condylar index were measured in preoperative MRIs. Clinical and functional evaluation included the Kujala Anterior Knee Pain Scale, the Lysholm Knee Score, the Tegner Activity Score, a subjective evaluation form and isokinetic muscle strength. RESULTS: Four patients had a Dejour type A dysplasia, two patients had no dysplasia. The mean (range) Caton-Dechamps index was 1.09 (0.95-1.16), TT-TG distance 10.9 mm (9.2-15.6 mm), patellar tilt 15° (4-32°) and lateral condylar index 82.0% (74-90%). One patient was lost to follow up, all others were followed for 2-5 years. All patients were satisfied with the clinical outcome. The Lysholm score increased from 55 (37-79) to 89 (76-100), the Tegner activity score from 3.6 (2-6) to 5.6 (5-7). The Kujala score postoperative was 90 (75-96). Some but not all patients had full strength recovery compared to the contralateral leg. CONCLUSION: We recommend measuring the lateral condylar index and considering the indication of a lateral trochlear lengthening osteotomy as an additional or isolated procedure in selected patients with trochlear dysplasia Dejour type A or lack of dysplasia and short lateral articular trochlea depending on the extent of the patellar instability. LEVEL OF EVIDENCE: Level IV, Case Series. TRIAL REGISTRATION NUMBER: NCT04378491, clinicaltrials.gov, May 7, 2020.

Total knee arthroplasty: posterior tibial slope influences the size but not the rotational alignment of the tibial component.

PURPOSE: The reasons leading to rotational tibial malalignment in total knee arthroplasties (TKAs) remain unclear. A previous cadaver study has shown an increase in internal rotation of the anatomical tibial axis (ATA) after the tibial cut. This study investigates the influence of tibial slope on the ATA and the size of the resected tibial surface. METHODS: CT scans of 20 cadaver knees were orientated in a standardized coordinate system and used to determine the position of the centres of rotation of the medial and lateral tibial articular surfaces and, hence, of the ATA, after a virtual resection of 6 mm with 0°, 3.5°, 7° and 10° slope, respectively. Furthermore, at each slope, the radii of the medial and lateral tibial articular surfaces after resection were calculated. RESULTS: Compared to resection of 6 mm with 0° slope, a slope of 3.5° resulted in a mean external rotation of the ATA of 0.9° (SD, 1.5°; P = 0.025). A slope of 7° resulted in a mean external rotation of the ATA of 1.0° (SD 2.0°; P = 0.030) and a slope of 10° had no influence on the rotation of the ATA. The radii of the medial and lateral articular surfaces of the cut tibiae were larger than those of the uncut tibia (P < 0.001). CONCLUSION: Differences in the posterior tibial slope should not contribute to a rotational malalignment when using the ATA to align the prosthetic tibial plateau. Although statistically significant, the change in ATA with increasing slope was negligible.

Functional limitations after lateral column lengthening osteotomy of the calcaneus are associated with lower quality of life.

PURPOSE: The purpose of this study was to quantify limitations in sagittal ankle range of motion (ROM) at least two years after lateral column lengthening osteotomy of the calcaneus (LLC) and their implications regarding quality of life. METHODS: Fifteen patients with a mean follow-up of 80 ± 27 months after LLC and 15 age-matched healthy persons participated in this study. Ankle joint complex ROM in plantarflexion and dorsiflexion was measured bilaterally using a goniometer and fluoroscopy (patients only). Quality of life was assessed using the short-form health questionnaire (SF36). Differences in ROM parameters (for the tibiotalar and subtalar joint) between sides (affected vs. unaffected) and between groups (patient vs. controls) and the relationship between ROM parameters and quality of life scores were assessed. RESULTS: ROM of the ankle joint complex on the affected side in patients was smaller than on the contralateral side (goniometer and fluoroscopy) and in healthy persons (goniometer; all P < .05). Among patients, SF36 total and pain scores, respectively, correlated with ROM of the subtalar joint (fluoroscopy; R = 0.379, P = 0.039 and R = 0.537, P = 0.001). Among patients and healthy persons, those with smaller dorsiflexion (goniometer) had lower quality of life scores. CONCLUSIONS: The smaller sagittal ROM of the affected ankle joint complex compared with the contralateral foot and healthy controls was mainly explained by limitations in the tibiotalar joint. Because of its association with quality of life, ROM should be considered in the treatment and rehabilitation planning in patients who are candidates for LLC.

Good vibrations: Itch induction by whole body vibration exercise without the need of a pruritogen.

Mechanically induced itch is an important cofactor in many patients with chronic itch. However, studying mechanical itch in a controlled environment is challenging because it is difficult to evoke. We investigated the use of whole body vibration (WBV) exercise, a training method used for musculoskeletal rehabilitation, to experimentally evoke mechanical itch. Mild to severe itch ascending from the soles to the groins was evoked in 16 of 20 healthy participants. We observed a characteristic on/off itch crescendo pattern reflecting the alternating intervals of vibration and no vibration. Wheals or an angioedema was absent, and serum mast cell tryptase was not increased by the exercise. Participants described the evoked sensation primarily as "itching" with some nociceptive components. Itch intensity correlated with the intensity of a concomitant erythema (R = 0.45, P = 0.043) and with the rise in skin temperature (R = 0.54, P = 0.017). Hence, WBV can be used as an easily applicable, noninvasive, investigator- and user-friendly framework for studying mechanical itch. Moreover, WBV allows to "switch itch on and off" rapidly and to simultaneously study interactions between itch, skin blood flow and skin temperature.

Prospective clinical evaluation of a novel anatomic cuff for forearm crutches in patients with osteoarthritis.

BACKGROUND: The use of forearm crutches has been associated with pain and neuropraxia along the ulnar bone. Whilst anatomic grips have improved comfort of crutch walking, to date anatomic forearm cuffs have not been clinically evaluated. The aim of this clinical pilot study was to determine if the use of forearm crutches with anatomic cuffs reduces pain and increases comfort and function in long-term users of forearm crutches during a 4-week period. METHOD: Prospective study in ten patients suffering from end-stage osteoarthritis of the lower extremity. All participants were long-term users of conventional forearm crutches. Participants used forearm crutches with an anatomically shaped cuff for 4-weeks. General health was assessed using the SF-36, and the crutches were evaluated using a newly developed questionnaire focusing on symptoms along the forearm. RESULTS: Pain and paresthesia along the forearms decreased by 3.3 points (95% confidence interval difference (CI): [-5.0; -1.6], p = .004) and 3.5 points (95%CI: [-5.1; -1.9], p = .002), respectively, after using the crutches with the new anatomic cuff for 4 weeks. Comfort and sense of security of crutch use increased by 3.0 points (95%CI: [1.3; 4.7], p = .007) and 2.4 points (95%CI: [0.7; 4.1], p = .024). Cross-correlation analysis revealed correlations among items in the same item category and no correlations between items of different item categories of the new questionnaires. CONCLUSION: An anatomically shaped cuff increases comfort of forearm crutches. Further research should confirm long-term clinical improvement. TRIAL REGISTRATION: This study was registered retrospectively in ISRCTN (TRN: ISRCTN 11135150 ) on 14/02/2017.

Marathon performance but not BMI affects post-marathon pro-inflammatory and cartilage biomarkers.

We tested the hypothesis that changes in serum cartilage oligomeric matrix protein (COMP), tumour necrosis factor α (TNF-α), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) concentration after regular endurance training and running a marathon race depend on body mass index (BMI) and/or on marathon performance. Blood samples were collected from 45 runners of varying BMI and running experience before and after a 10-week marathon training programme and before, immediately and 24 h after a marathon race. Serum biomarker concentrations, BMI and marathon finishing time were measured. The mean (95% confidence interval (CI)) changes from before to immediately after the marathon were COMP: 4.09 U/L (3.39-4.79 U/L); TNF-α: -1.17 mg/L (-2.58 to 0.25 mg/L); IL-6: 12.0 pg/mL (11.4-12.5 pg/mL); and hsCRP: -0.08 pg/mL (-0.14 to -0.3 pg/mL). The mean (95% CI) changes from immediately after to 24 h after the marathon were COMP: 0.35 U/L (-0.88 to 1.57 U/L); TNF-α: -0.43 mg/L (-0.99 to 0.13 mg/L); IL-6: -9.9 pg/mL (-10.5 to -9.4 pg/mL); and hsCRP: 1.52 pg/mL (1.25-1.79 pg/mL). BMI did not affect changes in biomarker concentrations. Differences in marathon finishing time explained 32% of variability in changes in serum hsCRP and 28% of variability in changes in serum COMP during the 24 h recovery after the marathon race (P < 0.001). Slower marathon finishing time but not a higher BMI modulates increases in pro-inflammatory markers or cartilage markers following a marathon race.

Validity and reliability of a portable gait analysis system for measuring spatiotemporal gait characteristics: comparison to an instrumented treadmill.

BACKGROUND: Gait analysis serves as an important tool for clinicians and other health professionals to assess gait patterns related to functional limitations due to neurological or orthopedic conditions. The purpose of this study was to assess the validity of a body-worn inertial sensor system (RehaGait®) for measuring spatiotemporal gait characteristics compared to a stationary treadmill (Zebris) and the reliability of both systems at different walking speeds and slopes. METHODS: Gait analysis was performed during treadmill walking at different speeds (habitual walking speed (normal speed); 15 % above normal walking speed; 15 % below normal walking speed) and slopes (0 % slope; 15 % slope) in 22 healthy participants twice 1 week apart. Walking speed, stride length, cadence and stride time were computed from the inertial sensor system and the stationary treadmill and compared using repeated measures analysis of variance. Effect sizes of differences between systems were assessed using Cohen's d, and limits of agreement and systematic bias were computed. RESULTS: The RehaGait® system slightly overestimated stride length (+2.7 %) and stride time (+0.8 %) and underestimate cadence (-1.5 %) with small effect sizes for all speeds and slopes (Cohen's d ≤ 0.44) except slow speed at 15 % slope (Cohen's d > 0.80). Walking speed obtained with the RehaGait® system closely matched the speed set on the treadmill tachometer. Intraclass correlation coefficients (ICC) were excellent for speed, cadence and stride time and for stride length at normal and fast speed at 0 % slope (ICC: .91-1.00). Good ICC values were found for stride length at slow speed at 0 % slope and all speeds at 15 % slope (ICC: .73-.90). Both devices had excellent reliability for most gait characteristics (ICC: .91-1.00) except good reliability for the RehaGait® for stride length at normal and fast speed at 0 % slope and at slow speed at 15 % slope (ICC: .80-.87). CONCLUSIONS: Larger limits of agreement for walking at 15 % slope suggests that uphill walking may influence the reliability of the RehaGait® system. The RehaGait® is a valid and reliable tool for measuring spatiotemporal gait characteristics during level and inclined treadmill walking.

Improvement of walking speed and gait symmetry in older patients after hip arthroplasty: a prospective cohort study.

BACKGROUND: Retraining walking in patients after hip or knee arthroplasty is an important component of rehabilitation especially in older persons whose social interactions are influenced by their level of mobility. The objective of this study was to test the effect of an intensive inpatient rehabilitation program on walking speed and gait symmetry in patients after hip arthroplasty (THA) using inertial sensor technology. METHODS: Twenty-nine patients undergoing a 4-week inpatient rehabilitation program following THA and 30 age-matched healthy subjects participated in this study. Walking speed and gait symmetry parameters were measured using inertial sensor device for standardized walking trials (2*20.3 m in a gym) at their self-selected normal and fast walking speeds on postoperative days 15, 21, and 27 in patients and in a single session in control subjects. Walking speed was measured using timing lights. Gait symmetry was determined using autocorrelation calculation of the cranio-caudal (CC) acceleration signals from an inertial sensor placed at the lower spine. RESULTS: Walking speed and gait symmetry improved from postoperative days 15-27 (speed, female: 3.2 and 4.5 m/s; male: 4.2 and 5.2 m/s; autocorrelation, female: 0.77 and 0.81; male: 0.70 and 0.79; P <0.001 for all). After the 4-week rehabilitation program, walking speed and gait symmetry were still lower than those in control subjects (speed, female 4.5 m/s vs. 5.7 m/s; male: 5.2 m/s vs. 5.3 m/s; autocorrelation, female: 0.81 vs. 0.88; male: 0.79 vs. 0.90; P <0.001 for all). CONCLUSIONS: While patients with THA improved their walking capacity during a 4-week inpatient rehabilitation program, subsequent intensive gait training is warranted for achieving normal gait symmetry. Inertial sensor technology may be a useful tool for evaluating the rehabilitation process during the post-inpatient period.

Forearm pressure distribution during ambulation with elbow crutches: a cross-sectional study.

BACKGROUND: Increasing numbers of patients require permanent walking aids to maintain mobility. Current elbow crutches are not designed for long-term use, and overuse is often associated with hematoma formation and pain along the forearm. We therefore hypothesized that the highest pressures between the forearm and crutch cuff during walking and stance are located in the ulnar region and that the level of weight-bearing, forearm circumference and kinematic parameters influence peak pressure values and pressure distribution. METHODS: Ten healthy adults participated in a cross-sectional study. A pressure sensor array was attached to the forearm of each participant separating the forearm into four quadrants (lateral, ulnar, intermediate and medial). Measurements were taken during crutch gait and during partial and full weight-bearing stance. A three-dimensional motion analysis system with reflective markers attached to the subject's body and to the crutches was used to obtain kinematic data. RESULTS: The mean pressure on the forearm during crutch gait was 37.5 kPa (SD 8.8 kPa). Highest mean pressure values were measured in the ulnar (41.0 kPa, SD 9.6 kPa) and intermediate (38.0 kPa, SD 9.0 kPa) quadrants. The center of pressure was mainly located in an oblique lamellar area in these two quadrants. With increasing weight-bearing on the crutches during stance, we observed a shift of the peak pressures towards the ulnar quadrant. The circumference of the forearm correlated with the peak pressure in the medial and intermediate quadrants during crutch gait (P < 0.05). Peak pressures on the forearm showed a trend towards correlation with crutch abduction, but no association with other kinematic parameters was detected. CONCLUSION: The pressure load on the forearm during crutch-assisted gait is located predominantly over the ulna and may be linked to a range of secondary conditions caused by crutch use including hematoma formation and pain.