Journal: Orthopaedic Journal of Sports Medicine

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SAGE

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2325-9671

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2017 - 201932020 - 202510
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Publications 1 - 10 of 13
  • Evaluation of Tibial Fixation Devices for Quadrupled Hamstring ACL Reconstruction
    Item type: Journal Article
    Ammann, Elias; Hecker, Andreas; Bachmann, Elias; et al. (2022)
    Orthopaedic Journal of Sports Medicine
    Background: Shortcomings to tibial-side fixation have been reported as causes of failure after anterior cruciate ligament reconstruction. Adjustable-loop suspensory devices have become popular; however, no comparison with hybrid fixation (ie, interference screw and cortical button) exists to our knowledge. Purpose: The purpose of this study was to compare the biomechanical properties of adjustable loop devices (ALDs) in full-tunnel and closed-socket configurations in relation to hybrid fixation. We hypothesized that primary stability of fixation by a tibial ALD will not be inferior to hybrid fixation. Study Design: Controlled laboratory study. Methods: Tibial fixation of a quadrupled tendon graft was biomechanically investigated in a porcine tibia–bovine tendon model using 5 techniques (n = 6 specimens each). The tested constructs included hybrid fixation with a cortical fixation button and interference screw (group 1), single cortical fixation with the full-tunnel technique using an open-suture strand button (group 2) or an ALD (group 3), or closed-socket fixation using 2 different types of ALDs (groups 4 and 5). Each specimen was evaluated using a materials testing machine (1000 cycles from 50-250 N and pull to failure). Force at failure, cyclic displacement, stiffness, and ability to pretension the graft during insertion were compared among the groups. Results: No differences in ultimate load to failure were found between the ALD constructs (groups 3, 4, and 5) and hybrid fixation (group 1). Cyclic displacement was significantly higher in group 2 vs all other groups (P < .001); however, no difference was observed in groups 3, 4, and 5 as compared with group 1. The remaining tension on the construct after fixation was significantly higher in groups 3 and 4 vs groups 1, 2, and 5 (P < .02 for all comparisons), irrespective of whether a full-tunnel or closed-socket approach was used. Conclusion: Tibial anterior cruciate ligament graft fixation with knotless ALDs achieved comparable results with hybrid fixation in the full-tunnel and closed-socket techniques. The retention of graft tension appears to be biomechanically more relevant than tunnel type. Clinical Relevance: The study findings emphasize the importance of the tension at which fixation is performed.
  • Chondrocytes From Device-Minced Articular Cartilage Show Potent Outgrowth Into Fibrin and Collagen Hydrogels
    Item type: Journal Article
    Levinson, Clara; Cavalli, Emma; Sindi, Dolman M.; et al. (2019)
    Orthopaedic Journal of Sports Medicine
    Background: Transplantation of autologous minced cartilage is an established procedure to repair chondral lesions. It relies on the migration of chondrocytes out of cartilage particles into a biomaterial. So far, there is no efficient way to finely mince cartilage. No consensus exists on the nature of the biomaterial to be used to promote chondrocyte migration. Purpose/Hypothesis: This study aimed to investigate the potential clinical use of a custom-made mincing device as well as a possible alternative biomaterial to fibrin glue. The device was tested for its effect on chondrocyte viability and on subsequent chondrocyte migration into either a fibrin or a collagen gel. We hypothesized that device mincing would allow finer cutting and consequently more cell migration and that the gelation mechanism of the collagen biomaterial, which uses the clotting of platelet-rich plasma, would enhance matrix production by outgrown chondrocytes. Study Design: Controlled laboratory study. Methods: Cartilage from 12 patients undergoing knee arthroplasty was taken from the femoral condyles and subsequently either hand minced or device minced. The viability and the degree of outgrowth were quantified with live/dead assay on the generated cartilage particles and on the gels in which these particles were embedded, respectively. Matrix deposition in the biomaterials by the outgrown cells was investigated with histology. Results: The device allowed rapid mincing of the cartilage and produced significantly smaller pieces than hand mincing. The initial chondrocyte viability in cartilage particles dropped by 25% with device mincing as compared with no mincing. However, the viability in hand-minced, device-minced, and unminced samples was no longer different after 7 and 28 days in culture. Outgrowth scores were similar among the 3 groups. Fibrin and collagen biomaterials equally supported chondrocyte outgrowth and survival, but neither promoted matrix deposition after in vitro culture. Conclusion: The outgrowth potential, the viability after 28 days in culture, and the matrix deposition were not different between the mincing techniques and the tested biomaterials, yet device mincing is faster and results in significantly smaller cartilage particles. Clinical Relevance: Device mincing could become the standard method to mince cartilage for second-generation cartilage repair techniques.
  • Structural Musculotendinous Parameters That Predict Failed Tendon Healing After Rotator Cuff Repair
    Item type: Journal Article
    Olthof, Maurits G.L.; Flück, Martin; Borbas, Paul; et al. (2023)
    Orthopaedic Journal of Sports Medicine
    Background: Healing of the rotator cuff after repair constitutes a major clinical challenge with reported high failure rates. Identifying structural musculotendinous predictors for failed rotator cuff repair could enable improved diagnosis and management of patients with rotator cuff disease. Purpose: To investigate structural predictors of the musculotendinous unit for failed tendon healing after rotator cuff repair. Study Design: Cohort study; Level of evidence, 2. Methods: Included were 116 shoulders of 115 consecutive patients with supraspinatus (SSP) tear documented on magnetic resonance imaging (MRI) who were treated with an arthroscopic rotator cuff repair. Preoperative assessment included standardized clinical and imaging (MRI) examinations. Intraoperatively, biopsies of the joint capsule, the SSP tendon, and muscle were harvested for histological assessment. At 3 and 12 months postoperatively, patients were re-examined clinically and with MRI. Structural and clinical predictors of healing were evaluated using logistic and linear regression models. Results: Structural failure of tendon repair, which was significantly associated with poorer clinical outcome, was associated with older age (β = 1.12; 95% CI, 1.03 to 1.26; P =.03), shorter SSP tendon length (β = 0.89; 95% CI, 0.8 to 0.98; P =.02), and increased proportion of slow myosin heavy chain (MHC)–I/fast MHC-II hybrid muscle fibers (β = 1.23; 95% CI, 1.07 to 1.42; P =.004). Primary clinical outcome (12-month postoperative Constant score) was significantly less favorable for shoulders with fatty infiltration of the infraspinatus muscle (β = –4.71; 95% CI, –9.30 to –0.12; P =.044). Conversely, a high content of fast MHC-II muscle fibers (β = 0.24; 95% CI, 0.026 to 0.44; P =.028) was associated with better clinical outcome. Conclusion: Both decreased tendon length and increased hybrid muscle fiber type were independent predictors for retear. Clinical outcome was compromised by tendon retearing and increased fatty infiltration of the infraspinatus muscle. A high content of fast MHC-II SSP muscle fibers was associated with a better clinical outcome. Registration: NCT02123784 (ClinicalTrials.govidentifier).
  • The Unloading Effect of Supramalleolar Versus Sliding Calcaneal Osteotomy for Treatment of Osteochondral Lesions of the Medial Talus: A Biomechanical Study
    Item type: Journal Article
    Flury, Andreas; Hodel, Sandro; Ongini, Esteban; et al. (2023)
    Orthopaedic Journal of Sports Medicine
    Background:In patients with osteochondral lesion, defects of the medial talus, or failed cartilage surgery, a periarticular osteotomy can unload the medial compartment.Purpose:To compare the effects of supramalleolar osteotomy (SMOT) versus sliding calcaneal osteotomy (SCO) for pressure redistribution and unloading of the medial ankle joint in normal, varus-aligned, and valgus-aligned distal tibiae.Study Design:Controlled laboratory study.Methods:Included were 8 cadaveric lower legs with verified neutral ankle alignment (lateral distal tibial angle [LDTA] = 0 degrees) and hindfoot valgus within normal range (0 degrees-10 degrees). SMOT was performed to modify LDTA between 5 degrees valgus, neutral, and 5 degrees varus. In addition, a 10-mm lateral SCO was performed and tested in each position in random order. Axial loading (700 N) of the tibia was applied with the foot in neutral alignment in a customized testing frame. Pressure distribution in the ankle joint and subtalar joint, center of force, and contact area were recorded using high-resolution Tekscan pressure sensors.Results:At neutral tibial alignment, SCO unloaded the medial joint by a mean of 10% +/- 10% or 66 +/- 51 N (P = .04) compared with 6% +/- 12% or 55 +/- 72 N with SMOT to 5 degrees valgus (P = .12). The achieved deload was not significantly different (ns) between techniques. In ankles with 5 degrees varus alignment at baseline, SMOT to correct LDTA to neutral insufficiently addressed pressure redistribution and increased medial load by 6% +/- 9% or 34 +/- 33 N (ns). LDTA correction to 5 degrees valgus (10 degrees SMOT) unloaded the medial joint by 0.4% +/- 14% or 20 +/- 75 N (ns) compared with 9% +/- 11% or 36 +/- 45 N with SCO (ns). SCO was significantly superior to 5 degrees SMOT (P = .017) but not 10 degrees SMOT. The subtalar joint was affected by both SCO and SMOT, where SCO unloaded but SMOT loaded the medial side.Conclusion:SCO reliably unloaded the medial compartment of the ankle joint for a neutral tibial axis. Changes in the LDTA by SMOT did not positively affect load distribution, especially in varus alignment. The subtalar joint was affected by SCO and SMOT in opposite ways, which should be considered in the treatment algorithm.Clinical Relevance:SCO may be considered a reliable option for beneficial load-shifting in ankles with neutral alignment or 5 degrees varus malalignment.
  • Muscle Degeneration Induced by Sequential Release and Denervation of the Rotator Cuff Tendon in Sheep
    Item type: Journal Article
    Wieser, Karl; Grubhofer, Florian; Hasler, Anita; et al. (2021)
    Orthopaedic Journal of Sports Medicine
    Background: In a sheep rotator cuff model, tenotomy predominantly induces fatty infiltration, and denervation induces mostly muscle atrophy. In clinical practice, myotendinous retraction after tendon tear or lateralization after tendon repair tear may lead to traction injury of the nerve. Purpose/Hypothesis: To analyze whether an additional nerve lesion during rotator cuff repair leads to further degeneration of the rotator cuff muscle in the clinical setting. We hypothesized that neurectomy after tendon tear would increase atrophy as well as fatty infiltration and that muscle paralysis after neurectomy would prevent myotendinous retraction after secondary tendon release. Study Design: Controlled laboratory study. Methods: Twelve Swiss alpine sheep were used for this study. For the 6 sheep in the tenotomy/neurectomy (T/N) group, the infraspinatus tendon was released; 8 weeks later, the suprascapular nerve was transected. For the 6 sheep in the neurectomy/tenotomy (N/T) group, neurectomy was performed, and the infraspinatus was tenotomized 8 weeks later. All sheep were sacrificed after 16 weeks. Magnetic resonance imaging (MRI) was performed before the first surgery (baseline) and then after 8 and 16 weeks. The MRI data were used to assess muscle volume, fat fraction, musculotendinous retraction, pennation angle, and muscle fiber length of the infraspinatus muscle. Results: Three sheep (2 in the T/N and 1 in the N/T group) had to be excluded because the neurectomy was incomplete. After 8 weeks, muscle volume decreased significantly less in the T/N group (73% ± 2% of initial volume vs 52% ± 7% in the N/T group; P < .001). After 16 weeks, the mean intramuscular fat increase was higher in the T/N group (36% ± 9%) than in the N/T group (23% ± 6%), without reaching significance (P = .060). After 16 weeks, the muscle volumes of the N/T (52% ± 8%) and T/N (49% ± 3%) groups were the same (P = .732). Conclusion: Secondary neurectomy after tenotomy of a musculotendinous unit increases muscle atrophy. Tenotomy of a denervated muscle is associated with substantial myotendinous retraction but not with an increase of fatty infiltration to the level of the tenotomy first group. Clinical Relevance: Substantial retraction, which is associated with hitherto irrecoverable fatty infiltration, should be prevented, and additional neurogenic injury during repair should be avoided to limit the development of further atrophy.
  • Sex-Specific Differences in Hip Muscle Cross-sectional Area and Fatty Infiltration in Patients With Femoroacetabular Impingement Syndrome
    Item type: Journal Article
    Douma, Mirjam V.; Casartelli, Nicola C.; Sutter, Reto; et al. (2023)
    Orthopaedic Journal of Sports Medicine
    Background: Patients with femoroacetabular impingement syndrome (FAIS) show sex-specific differences in hip muscle function, hip morphology, and symptoms. Possible differences in hip muscle characteristics between men and women with FAIS are unknown. Purpose: To compare hip muscle cross-sectional area (CSA) and fatty infiltration between men and women with FAIS and investigate possible associations with patient-reported outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: We retrospectively analyzed preoperative axial pelvic magnetic resonance imaging scans of 104 patients (54 women) who underwent hip surgery for FAIS. The main outcome measures were side-to-side percentage asymmetry in hip muscle CSA and involved-side fatty infiltration as measured with the Goutallier scale for a total of 10 hip muscles. Patient-reported outcomes included duration of hip symptoms, iHOT-12 (12-item International Hip Outcome Tool), and Hip Sports Activity Scale. Results: Women showed larger hip abductor muscle CSA asymmetry than men (P =.018), particularly for the gluteus medius (P =.049), while men exhibited more fatty streaks (grade 1) in the gluteus medius (P =.015) than women. Duration of symptoms was associated only with fatty infiltration of obturator externus in men (rS = –0.55, P =.018). iHOT-12 was associated with CSA asymmetry of the gluteus minimus (r = –0.41, P =.011) and iliopsoas (r = –0.36, P =.028) in men and with piriformis fatty infiltration (rS = –0.56, P =.030) in women. The Hip Sports Activity Scale was associated with iliopsoas CSA asymmetry (rS = 0.32, P =.026) and with fatty infiltration of the tensor fasciae latae (rS = –0.45, P =.046) and obturator externus (rS = –0.50, P =.023) in women. Conclusion: Patients with FAIS demonstrated few sex-specific quantitative and qualitative alterations of hip muscles. Women showed greater hip abductor muscle atrophy than men, particularly for the gluteus medius, while men showed a higher degree of fatty infiltration in this same muscle. The duration of hip symptoms was not associated with muscle atrophy. Patient-reported hip pain/function and sport activity level were only moderately associated with isolated muscular variables.
  • Biomechanics of Ankle Ligament Reconstruction: A Cadaveric Study to Compare Stability of Reconstruction Techniques Using 1 or 2 Fibular Tunnels
    Item type: Journal Article
    Gautschi, Martina; Bachmann, Elias; Shirota, Camila; et al. (2020)
    Orthopaedic Journal of Sports Medicine
    Background: Anatomic lateral ankle ligament reconstruction has been proposed for patients with chronic ankle instability. A reliable approach is a reconstruction technique using an allograft and 2 fibular tunnels. A recently introduced approach that entails 1-fibular tunnel reconstruction might reduce the risk of intraoperative complications and ultimately improve patient outcome. Hypothesis: We hypothesized that both reconstruction techniques show similar ankle stability (joint laxity and stiffness) and are similar to the intact joint condition. Study Design: Controlled laboratory study. Methods: A total of 10 Thiel-conserved cadaveric ankles were divided into 2 groups and tested in 3 stages-intact, transected, and reconstructed lateral ankle ligaments-using either the 1- or the 2-fibular tunnel technique. To quantify stability in each stage, anterior drawer and talar tilt tests were performed in 0 degrees, 10 degrees, and 20 degrees of plantarflexion (anterior drawer test) or dorsiflexion (talar tilt test). Bone displacements were measured using motion capture, from which laxity and stiffness were calculated together with applied forces. Finally, reconstructed ligaments were tested to failure in neutral position with a maximal applicable torque in inversion. A mixed linear model was used to describe and compare the outcomes. Results: When ankle stability of intact and reconstructed ligaments was compared, no significant difference was found between reconstruction techniques for any flexion angle. Also, no significant difference was found when the maximal applicable torque of the 1-tunnel technique (9.1 +/- 4.4 N center dot m) was compared with the 2-tunnel technique (8.9 +/- 4.8 N center dot m). Conclusion: Lateral ankle ligament reconstruction with an allograft using 1 fibular tunnel demonstrated similar biomechanical stability to the 2-tunnel approach.
  • Osteoconductive Scaffold Placed at the Femoral Tunnel Aperture in Hamstring Tendon ACL Reconstruction: A Randomized Controlled Trial
    Item type: Journal Article
    Götschi, Tobias; Hodel, Sandro; Kühne, Nathalie; et al. (2023)
    Orthopaedic Journal of Sports Medicine
    Background: Bone tunnel enlargement after single-bundle anterior cruciate ligament reconstruction remains an unsolved problem that complicates revision surgery. Hypothesis: Positioning of an osteoconductive scaffold at the femoral tunnel aperture improves graft-to-bone incorporation and thereby decreases bone tunnel widening. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: In a 1:1 ratio, 56 patients undergoing primary anterior cruciate ligament reconstruction were randomized to receive femoral fixation with cortical suspension fixation and secondary press-fit fixation at the tunnel aperture of the tendon graft only (control) or with augmentation by an osteoconductive scaffold (intervention). Adverse events, patient-reported outcomes, and passive knee stability were recorded over 2 years after the index surgery. Three-dimensional bone tunnel widening was assessed using computed tomography at the time of surgery and 4.5 months and 1 year postoperatively. Results: The intervention group exhibited a similar number of adverse events as the control group (8 vs 10; P =.775) including 2 partial reruptures in both groups. The approach was feasible, although 1 case was encountered where the osteoconductive scaffold was malpositioned without adversely affecting the patient’s recovery. There was no difference between the intervention and control groups in femoral bone tunnel enlargement, as expressed by the relative change in tunnel volume from surgery to 4.5 months (mean ± SD, 36% ± 25% vs 40% ± 25%; P =.644) and 1 year (19% ± 20% vs 17% ± 25%; P =.698). Conclusion: Press-fit graft fixation with an osteoconductive scaffold positioned at the femoral tunnel aperture is safe but does not decrease femoral bone tunnel enlargement at postoperative 1 year. Registration: NCT03462823 (ClinicalTrials.gov identifier).
  • Biomechanical Evaluation of a Novel Loop Retention Mechanism for Cortical Graft Fixation in ACL Reconstruction
    Item type: Journal Article
    Götschi, Tobias; Rosenberg, George; Li, Xiang; et al. (2020)
    Orthopaedic Journal of Sports Medicine
    Background: Implant fixation by means of a cortical fixation device (CFD) has become a routine procedure in anterior cruciate ligament reconstruction. There is no clear consensus whether adjustable-length CFDs are more susceptible to loop lengthening when compared with pretied fixed-length CFDs. Purpose: To assess biomechanical performance measures of 3 types of CFDs when subjected to various loading protocols. Study Design: Controlled laboratory study. Methods: Three types of CFDs underwent biomechanical testing: 1 fixed length and 2 adjustable length. One of the adjustable-length devices is based on the so-called finger trap mechanism, and the other is based on a modified sling lock mechanism. A device-only test of 5000 cycles (n = 8 per group) and a tendon-device test of 1000 cycles (n = 8 per group) with lower and upper force limits of 50 and 250 N, respectively, were applied, followed by ramp-to-failure testing. Adjustable-length devices then underwent further cyclic testing with complete loop unloading (n = 5 per group) at each cycle, as well as fatigue testing (n = 3 per group) over a total of 1 million cycles. Derived mechanical parameters were compared among the devices for statistical significance using Kruskal-Wallis analysis of variance followed by post hoc Mann-Whitney U testing with Bonferroni correction. Results: All CFDs showed elongation <2 mm after 5000 cycles when tested in an isolated manner and withstood ultimate tensile forces in excess of estimated peak in vivo forces. In both device-only and tendon-device tests, differences in cyclic performance were found among the devices, favoring adjustable-length fixation devices over the fixed-length device. Completely unloading the suspension loops, however, led to excessive loop lengthening of the finger trap device, whereas the modified sling lock device remained stable throughout the test. The fixed-length device displayed superior ultimate strength over both adjustable-length devices. Both adjustable-length devices showed adequate fatigue behavior during high-cyclic testing. Conclusion: All tested devices successfully prevented critical construct elongation when tested with constant tension and withstood ultimate loads in excess of estimated in vivo forces during the rehabilitation phase. The finger trap device gradually lengthened excessively when completely unloaded during cyclic testing.
  • The Influence of Subscapularis Muscle Split Location on Subscapularis Function After the Latarjet Procedure
    Item type: Journal Article
    Belotti, Natalia; Fox, Aaron S.; Henze, Janina; et al. (2025)
    Orthopaedic Journal of Sports Medicine
    Background: Splitting the subscapularis in the Latarjet procedure is known to influence subscapularis muscle mechanics postoperatively; however, the influence of split level on postoperative muscle and joint function remains poorly understood. Purpose: To assess the effects of midlevel, lower-third, and upper-third subscapularis split levels in the Latarjet procedure on subscapularis lines of action and moment arms in the shoulder abduction, abduction and external rotation (ABER), and apprehension positions. Study Design: Controlled laboratory study. Methods: The Latarjet procedure was performed on 8 fresh-frozen human cadaveric upper extremities with a simulated 20% anteroinferior glenoid bone defect. A midwidth subscapularis muscle belly split was first performed on all specimens in which the conjoint tendon was routed. Lines of action and moment arms of 4 subregions of the subscapularis muscle (superior, mid-superior, mid-inferior, and inferior) were quantified radiographically with the conjoint tendon unloaded and loaded and the glenohumeral joint positioned in (1) 0° of abduction, (2) 90° of abduction, (3) 90° of abduction and full external rotation (ABER), and (4) the apprehension position, defined as ABER with 30° of horizontal extension. Testing was then repeated in random order after rerouting the conjoint tendon through both an upper- and then lower-third subscapularis split. Utmost care was taken to ensure that the subscapularis muscle integrity was not disrupted during the rerouting process. Results: Subscapularis splitting in Latarjet surgery deformed the muscle fibers below the split level, significantly increasing the inferior inclination of subscapularis muscle lines of action, but only for the midlevel and lower-third subscapularis split levels (P < .001). This increased inferior inclination was significantly greater in the ABER and apprehension positions compared with those at 0° and 90° of abduction (P < .05). In the ABER and apprehension positions, the adduction moment arms of the mid-superior subscapularis muscle subregion were also significantly larger for the midlevel split compared with the lower-third and upper-third split (P < .05), indicating greater depressor capacity. Conclusion: Latarjet surgery deforms subscapularis muscle fibers below the level of the split, changing subscapularis leverage and line of force. The midlevel subscapularis muscle split in the Latarjet procedure confers greater mechanical advantage in terms of shoulder depressor function and stabilizing potential than that associated with an upper-third or lower-third split, particularly in the ABER and apprehension positions. Clinical Relevance: Subscapularis muscle leverage and force potential are significantly influenced by split location in Latarjet surgery. A midlevel subscapularis split is likely to provide the greatest mechanical stability, particularly in positions of shoulder instability.
Publications 1 - 10 of 13