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European Journal of Orthopaedic Surgery... Aug 2021Hidden instability could be one of the reasons for reoccurring stiffness after arthrolysis in posttraumatic elbows. Associated instability in stiff posttraumatic elbows...
BACKGROUND
Hidden instability could be one of the reasons for reoccurring stiffness after arthrolysis in posttraumatic elbows. Associated instability in stiff posttraumatic elbows is clinically hard to detect. Surgical treatment for instability and stiffness in the same surgical setting is challenging and has not been evaluated as of yet.
HYPOTHESIS
The primary hypothesis assumes (1) the existence of a posttraumatic "stiff and unstable elbow" and (2) that coexisting instability can be detected by arthroscopic instability testing. The secondary objective was to report the midterm results after arthrolysis and ligament stabilization in the stiff and unstable elbow.
METHODS
From 2005 to 2015, 55 patients received arthroscopic arthrolysis of the elbow due to posttraumatic elbow stiffness at our institution. The arthroscopic instability was categorized into three grades with a switching stick: grade I (= stable), grade II (mild instability) and grade III (grossly instable). In cases of persisting instability (grade II-III), a ligament stabilization procedure was performed and all patients were followed up clinically at a minimum of 12 months. Besides ROM and clinical joint stability, PROs (patient reported outcomes) were assessed with the PREE-score (patient-rated elbow evaluation) and the Oxford-Elbow-score (OES). Furthermore, the MEPS (Mayo-elbow-performance-score) was assessed.
RESULTS
Out of 55 cases presenting for arthrolysis, coexisting elbow instability was detected during arthroscopic instability testing in 22 cases (40%). All 22 patients received additional ligament stabilization. At final follow-up 62.7 ± 35.7 months postoperatively, 20 patients (12 men; 8 women) with a mean age of 42 ± 16.8 were available. PREE, OES and MEPS were 19.8 ± 25.3, 37.5 ± 9.8 and 80 ± 14.5, respectively. ROM improved significantly from 95° ± 29° to 110° ± 24° postoperatively (p = 0.045). Five patients required revision arthrolysis within the follow-up period (20%). One patient demonstrated persisting instability (5%).
CONCLUSION
Intraoperative instability diagnostics during arthroscopic arthrolysis helps detect persisting posttraumatic instability and may provide a solid indication for a concurrent ligament stabilization procedure. This study is the first to present the postoperative results after arthrolysis with stabilization of the posttraumatic, stiff and unstable elbow. However, the results are heterogenic with 25% requiring revision arthrolysis. Therefore, the stiff but unstable elbow remains a complex clinical presentation in need of further investigations.
LEVEL OF EVIDENCE
IV.
Topics: Elbow; Elbow Joint; Female; Humans; Joint Instability; Male; Orthopedic Procedures; Range of Motion, Articular; Retrospective Studies; Treatment Outcome
PubMed: 33417047
DOI: 10.1007/s00590-020-02846-5 -
Journal of Biomechanics Jul 2023The primary purpose of this study was to examine sex differences in lower extremity joint stiffness during vertical drop jump performance. A secondary purpose was to...
The primary purpose of this study was to examine sex differences in lower extremity joint stiffness during vertical drop jump performance. A secondary purpose was to examine the potential influence of sex on the relationship between joint stiffness and jump performance. Thirty healthy and active individuals performed 15-drop jumps from 30 and 60 cm boxes. Hip, knee, and ankle joint stiffnesses were calculated for subphases of landing using a 2nd order polynomial regression model. Males had greater hip stiffness during the loading phase in drop jumps from both box heights than females' drop jump from 60 cm box. Also, males had a greater ground reaction force at the end of eccentric phase, net jump impulse, and jump height regardless of box height. The 60 cm box height increased knee stiffness during the loading phase, but reduced hip stiffness during the loading phase and knee and ankle stiffness during the absorption phase regardless of sex. Joint stiffnesses significantly predicted drop jump height for females (p < .001, r = 0.579), but not for males (p = .609, r = -0.053). These results suggest that females may have different strategies to maximize drop jump height as compared to males.
Topics: Humans; Male; Female; Biomechanical Phenomena; Lower Extremity; Knee Joint; Knee; Ankle; Ankle Joint
PubMed: 37300979
DOI: 10.1016/j.jbiomech.2023.111667 -
Journal of Applied Physiology... Sep 2020Joint stiffness is often measured to make inferences about the stiffness of muscle groups, but little can be gleaned about individual muscles. Decomposing the muscular...
Joint stiffness is often measured to make inferences about the stiffness of muscle groups, but little can be gleaned about individual muscles. Decomposing the muscular origins of joint stiffness may inform treatment targets for conditions like spasticity. To complement joint stiffness, shear wave ultrasound elastography has been used to estimate the material properties of individual muscles. If shear wave measures are to be used to assess the muscular origins of joint stiffness, then changes in shear wave velocity should strongly relate to changes in joint stiffness. Here, we estimated the relationships between shear wave velocity in the primary plantar flexors [soleus (SOL) and medial gastrocnemius (MG)] and ankle joint stiffness. Participants performed isometric plantar flexion tasks at a range of activations (0-40%), while joint stiffness and muscle shear wave velocities were obtained. We observed a strong, linear relationship between plantar flexor shear wave velocities and joint stiffness. Remarkably, the parameter estimates of this stiffness-shear wave relationship strongly agreed with theoretical and literature-based estimates [SOL:MG parameter ratios = 2.83 (observed) vs. 2.85 (expected from theoretical stiffness ratio)]. Finally, a musculoskeletal model of the plantar flexors was able to accurately reproduce joint stiffness estimates, and shear wave velocities could explain 80-95% of the variance in modeled muscle stiffness. These findings suggest that shear wave velocity may be used to infer the muscular origins of changes in joint stiffness. Shear wave velocity is commonly assessed to infer the muscular origins of changes in joint stiffness, but the exact relationship between shear wave velocity changes in muscle and joint stiffness changes remains unknown. Here, we systematically evaluated and quantified this relationship in the plantar flexors. Our results provide evidence for the ability of shear wave velocity to elucidate the muscular origins of joint stiffness changes.
Topics: Ankle; Ankle Joint; Elasticity Imaging Techniques; Humans; Muscle, Skeletal; Ultrasonography
PubMed: 32644909
DOI: 10.1152/japplphysiol.00133.2020 -
Clinics in Podiatric Medicine and... Jul 2020Although most primary lateral ankle ligament repairs have a high success rate, as with any surgery, failures and the need for revision can occur. Nonanatomic lateral... (Review)
Review
Although most primary lateral ankle ligament repairs have a high success rate, as with any surgery, failures and the need for revision can occur. Nonanatomic lateral ankle ligament repairs have fallen out of favor because of the increased stiffness and resultant change in mechanics of the functioning tendon that is normally used. Allograft anatomic lateral ankle ligament reconstruction for revision surgery has gained popularity over the last few years. This article discusses the factors that can lead to failure and the revision technique.
Topics: Ankle Joint; Humans; Joint Instability; Lateral Ligament, Ankle; Reoperation; Treatment Failure
PubMed: 32471612
DOI: 10.1016/j.cpm.2020.03.002 -
Journal of Applied Biomechanics Oct 2022Dynamic joint stiffness (or simply "stiffness") is a customization criteria used to tune mechanical properties of orthotic and prosthetic devices. This study examines...
Dynamic joint stiffness (or simply "stiffness") is a customization criteria used to tune mechanical properties of orthotic and prosthetic devices. This study examines metatarsophalangeal (MTP) joint stiffness during the toe-rocker phase of barefoot walking and establishes baseline characteristics of MTP joint stiffness. Ten healthy individuals walked at 4 speeds (0.4, 0.6, 0.8, and 1.0 statures·s-1) over level ground. MTP sagittal plane joint angles and moments were calculated during the toe-rocker phase of stance. Least-squares linear regressions were conducted on the MTP moment versus angle curve to determine joint stiffness during early toe rocker and late toe rocker. Multilevel linear models were used to test for statistically significant differences between conditions. Early toe rocker stiffness was positive, while late toe rocker was negative. Both early toe rocker and late toe rocker stiffness increased in magnitude significantly with speed. This study establishes baseline characteristics of MTP joint stiffness in healthy walking, which previously had not been examined through a range of controlled walking speeds. This information can be used in the future as design criteria for orthotic and prosthetic ankle and ankle-foot devices that can imitate, support, and facilitate natural human foot motion during walking better than existing devices.
Topics: Ankle Joint; Biomechanical Phenomena; Gait; Humans; Metatarsophalangeal Joint; Range of Motion, Articular; Toes; Walking; Walking Speed
PubMed: 36096476
DOI: 10.1123/jab.2021-0385 -
Journal of the Mechanical Behavior of... Feb 2022A flexible biologic band, ACL is the most injured and ruptured ligament in the knees of humans and animals. This research aims to produce synthetic anterior cruciate...
A flexible biologic band, ACL is the most injured and ruptured ligament in the knees of humans and animals. This research aims to produce synthetic anterior cruciate ligaments (ACLs) and compare these ligaments' mechanical and fatigue life properties with the natural ACL and commercial synthetic grafts. Artificial ligaments were designed as a core-sheath type structure. The core consisted of straight, parallel yarns and the sheath was a tubular fabric produced by weaving or braiding techniques from polyester or Vectran® yarns. The mechanical properties of the resulting artificial ligaments (AL) were tested before and after the fatigue test and compared to those of the natural ACL and commercial artificial ACLs in the market. Results showed that all ligaments had sufficient tensile strength, and they retained it after the fatigue test. If constructed sheath and core parts were from the same type of yarns, the breaking load of ligaments was higher. The breaking strain and stiffness of woven structures, particularly with Vectran cores, were better than braided ones. After the fatigue test, the breaking strain and stiffness of AL structures with a braided sheath or polyester core were improved. This finding suggests that to prevent the laxity of knee preconditioning of the ligament is necessary if the fabric structure or yarn inherently has high breaking strain and low stiffness. Overall, this study shows that a variety of suitable candidates for replacing ruptured anterior cruciate ligaments could be developed by carefully combining the fatigue-resistant yarns with leno, narrow, and braided structures.
Topics: Animals; Anterior Cruciate Ligament; Anterior Cruciate Ligament Injuries; Biomechanical Phenomena; Humans; Knee Joint; Ligaments; Materials Testing; Tensile Strength
PubMed: 34973487
DOI: 10.1016/j.jmbbm.2021.105063 -
Journal of Neuroengineering and... Aug 2021User preference has the potential to facilitate the design, control, and prescription of prostheses, but we do not yet understand which physiological factors drive...
BACKGROUND
User preference has the potential to facilitate the design, control, and prescription of prostheses, but we do not yet understand which physiological factors drive preference, or if preference is associated with clinical benefits.
METHODS
Subjects with unilateral below-knee amputation walked on a custom variable-stiffness prosthetic ankle and manipulated a dial to determine their preferred prosthetic ankle stiffness at three walking speeds. We evaluated anthropomorphic, metabolic, biomechanical, and performance-based descriptors at stiffness levels surrounding each subject's preferred stiffness.
RESULTS
Subjects preferred lower stiffness values at their self-selected treadmill walking speed, and elected to walk faster overground with ankle stiffness at or above their preferred stiffness. Preferred stiffness maximized the kinematic symmetry between prosthetic and unaffected joints, but was not significantly correlated with body mass or metabolic rate.
CONCLUSION
These results imply that some physiological factors are weighted more heavily when determining preferred stiffness, and that preference may be associated with clinically relevant improvements in gait.
Topics: Ankle; Ankle Joint; Artificial Limbs; Biomechanical Phenomena; Gait; Humans; Patient Preference; Prosthesis Design; Walking
PubMed: 34433472
DOI: 10.1186/s12984-021-00916-1 -
Arthritis Research & Therapy Sep 2023Osteoarthritis (OA) is a degenerative joint disease associated with aging, which often leads to joint stiffness and disability. Exercise is one of the most important...
BACKGROUND
Osteoarthritis (OA) is a degenerative joint disease associated with aging, which often leads to joint stiffness and disability. Exercise is one of the most important non-pharmacological treatments and is prescribed as an indispensable treatment for OA. However, whether physical exercise is beneficial for preventing the progression of OA symptoms with age is poorly understood. We investigated the effects of exercise on spontaneously developed knee OA using male senescence-accelerated mouse prone 8 (SAMP8).
METHODS
To examine age-related changes in the knee joints of SAMP8, knee articular cartilage changes, synovitis, knee joint flexion and extension angles, swelling, walking ability, and quadriceps muscle atrophy were analyzed at 3, 5, 7, and 9 months. SAMP8 were required to run at a speed of 10 m/min for 15 min/day from 7 to 9 months of age. The knee joint pathologies and symptoms of exercising and non-exercising mice were compared by histological, immunohistochemical, and morphometrical analyses.
RESULTS
The mice presented with various histological changes, including cartilage destruction, osteocyte formation, synovitis, declined joint angles, and swelling. Notably, medial and posterior cartilage destruction was more severe than that of the lateral and anterior cartilage. Knee joint angles were significantly correlated with the histological scores (modified Mankin and OARSI, osteophyte formation and synovial lining cell layer). Exercise did not attenuate cartilage degeneration in the medial and posterior tibial plateau, although the articular cartilage of the anterior and lateral tibial plateau and its histological scores was remained and significantly improved, respectively, by exercise. Exercise suppressed the age-related decline of collagen type II-positive areas in the remaining articular cartilage and improved the OA symptoms. Exercise reduced the expression of monocyte chemoattractant protein (MCP)-1 and tumor necrosis factor (TNF)-α positive macrophages in the synovium.
CONCLUSION
This study revealed that SAMP8 developed spontaneous knee OA with age, which resembled the disease symptoms in humans. Low-intensity exercise temporarily alleviated degeneration of the remaining cartilage, synovitis, and age-related decreases in knee flexion angle, stride length, and muscle atrophy in SAMP8. However, exercise during OA progression with age may cause mechanical stress that could be both beneficial and detrimental to joint health.
Topics: Humans; Mice; Male; Animals; Infant; Osteoarthritis, Knee; Knee Joint; Walking; Cartilage, Articular; Synovitis
PubMed: 37710278
DOI: 10.1186/s13075-023-03162-z -
Journal of Healthcare Engineering 2020While individual ankle and metatarsophalangeal joint stiffness is related to training intensity and sport performances, sport athletes may develop specific passive joint...
While individual ankle and metatarsophalangeal joint stiffness is related to training intensity and sport performances, sport athletes may develop specific passive joint stiffness among the spectrum from endurance to powerful types of sports. The objective of this study examined whether marathon runners, basketball players, and other sports athletes would demonstrate distinct passive ankle and metatarsophalangeal joint stiffness as well as vertical stiffness. Fifteen marathon runners, nineteen basketball players, and seventeen other sports athletes performed both joint stiffness measurement and single-leg hopping tests. We used a computerized dynamometer to control foot alignment and speed for passive ankle and metatarsophalangeal joint stiffness measurements. We calculated vertical stiffness by body deceleration and body mass displacement during hopping on the force platform. One-way ANOVA was performed to identify the group differences. Bivariate correlation test was also performed among ankle, metatarsophalangeal, and vertical stiffness. The basketball group displayed 13% higher ankle passive stiffness than the other sports players group ( = 0.03). Metatarsophalangeal joint passive stiffness in sitting and standing positions was 23% higher in the basketball group than the runner and other sports athlete groups ( < 0.01). However, there was no significant group differences in metatarsophalangeal joint passive stiffness and vertical stiffness. Significant correlations among all stiffness variables were determined ( < 0.05). These findings indicate that ankle and metatarsophalangeal joint passive stiffness, rather than vertical leg stiffness, would be in relation to types of sports participation. Ankle and toe strengthening exercises could improve basketball players' performance and prevent injury.
Topics: Adult; Ankle Joint; Athletic Performance; Basketball; Humans; Male; Metatarsophalangeal Joint; Movement; Running; Young Adult
PubMed: 32257087
DOI: 10.1155/2020/9025015 -
International Journal For Numerical... Jan 2021Knee connective tissues are mainly responsible for joint stability and play a crucial role in restraining excessive motion during regular activities. The damage...
Knee connective tissues are mainly responsible for joint stability and play a crucial role in restraining excessive motion during regular activities. The damage mechanism of these tissues is directly linked to the microscale collagen level. However, this mechanical connection is still unclear. During this investigation, a multiscale fibril-reinforced hyper-elastoplastic model was developed and statistically calibrated. The model is accounting for the structural architecture of the soft tissue, starting from the tropocollagen molecule that forms fibrils to the whole soft tissue. Model predictions are in agreement with the results of experimental and numerical studies. Further, damage initiation and propagation in the collagen fiber were computed at knee ligaments and located mainly in the superficial layers. Results indicated higher crosslink density required higher tensile stress to elicit fibril damage. This approach is aligned with a realistic simulation of a damaging process and repair attempt. To the best of our knowledge, this is the first model published in which the connective tissue stiffness is simultaneously predicted by encompassing the mesoscopic scales between the molecular and macroscopic levels.
Topics: Biomechanical Phenomena; Connective Tissue; Knee Joint; Ligaments, Articular; Stress, Mechanical
PubMed: 33174350
DOI: 10.1002/cnm.3413