Clinical Outcomes of Operative Repair for Patients Who Fail to Conserve the Complete Rupture of the Collateral Ligament in the Proximal Interphalangeal Joint

Objective: The purpose of this study was to compare the preoperative and postoperative outcomes of surgical treatment for patients who fail to conserve the complete rupture of the collateral ligament in the proximal interphalangeal (PIP) joint.Methods: A complete rupture of the collateral ligament was confirmed by a radiologist using ultrasound or magnetic resonance imaging for patients who had symptoms after 4 weeks of conservative treatment. Eleven patients underwent operative collateral ligament repair using an anchor. All patient was followed up for at least 6 months postoperatively. We evaluated clinical outcomes preoperatively and at 6 months follow-up: (1) range of motion of the PIP, (2) joint stability, (3) Visual Analog Scale score, (4) fusiform index of the PIP joint, and (5) functional & cosmetic satisfaction.Results: There was no instability in the lateral stress test at 6-month follow-up. The ranges of motion of the PIP were not statistically different between preoperative and at 6-month follow-up. Patients had less pain but the cosmetic appearance of the PIP joint did not improve. Functional satisfaction differed statistically, but there was no difference in cosmetic satisfaction.Conclusion: Surgical treatment for patients who fail to conserve the complete rupture of the collateral ligament in the PIP joint can provide good joint stability, functional recovery.

Incidence of Patterns of Bony modification of Neck of the Talus in Indian Population

Objective: The present study is an attempt to determine the various types of bony modifications on the dorsum of the neck of the human tali of both feet due to the continuous habit of squatting in humans and correlating these findings to the existing literature. Materials and Methods: 70 tali of unknown sex, obtained from the Department of Anatomy of MVJ Medical College and Research Hospital, Bangalore were used for the study. The dorsal surface of talar neck was carefully examined for the presence of medial and lateral squatting facets, combined facets, continuous gutter shaped facets and extension of trochlear surface. The collected data were tabulated and percentage of each facets and trochlear extensions were calculated. Statistical analysis of data was performed. Results: Out of 70 dry human tali, lateral squatting facets were present in 29 (41.4%) bones and medial squatting facets were seen in 11 (15.7%) bones, gutter shaped facets in 12 (17.1%) tali and combined facet present in 10 (14.2%) tali. Complete absence of facet was observed in 8 tali. Lateral extension of trochlear surface on the dorsum of neck was seen in 60 (85.7%) bones and medial trochlear extension was seen in 8(11.5%) bones. Lateral squatting facets were more common on right side but medial, gutter and combined facets though less frequent were seen more on left side. Lateral extensions were more commonly seen than medial extensions. Conclusion: The knowledge of incidence of these modifications on the dorsal surfaces of neck of the talus acts as a key anthropological factor to identify the racial and regional origin of unclaimed skeleton. Hence the results of this study will be of great help for forensic experts, anthropologist who are handling the unidentified skeletons. KEY WORDS: Squatting Facets, Talus, Trochlear extensions, Sub Talar Joint Stability.

Enthesis strength, toughness and stiffness: an image-based model comparing tendon insertions with varying bony attachment geometries

Tendons of the body differ dramatically in their function, mechanics and range of motion, but all connect to bone via an enthesis. Effective force transfer at the enthesis enables joint stability and mobility, with strength and stiffness arising from a fibrous architecture. However, how enthesis toughness arises across tendons with diverse loading orientations remains unclear. To study this, we performed simultaneous imaging of the bone and tendon in entheses that represent the range of tendon-to-bone insertions and extended a mathematical model to account for variations in insertion and bone geometry. We tested the hypothesis that toughness, across a range of tendon entheses, could be explained by differences observed in interactions between fibre architecture and bone architecture. In the model, toughness arose from fibre reorientation, recruitment and rupture, mediated by interactions between fibres at the enthesis and the bony ridge abutting it. When applied to tendons sometimes characterized as either energy-storing or positional, the model predicted that entheses of the former prioritize toughness over strength, while those of the latter prioritize consistent stiffness across loading directions. Results provide insight into techniques for surgical repair of tendon-to-bone attachments, and more broadly into mechanisms for the attachment of highly dissimilar materials.

Knee joint stability following fixation of tibial plateau fracture by angular locking plate fixation

<p class="abstract"><strong>Background:</strong> Injuries to the tibial plateau generally occur because of a force directed either medially or laterally an axial compressive force or both an axial force and force from the side. Tibial plateau fractures resulting frequently in functional impairment.</p><p class="abstract"><strong>Methods: </strong>The total of cases included in the study was 47 in number. More than 20 years old patients of both sexes with tibial plateau fractures attended in the study. Proper informed consent was taken from the patients under the study and purpose of the study was explained. Ethical approval was obtained from the Institutional Ethics Committee. All data were processed, analyzed, and disseminated by MS Office and Statistical package for social sciences (SPSS) version 26 as per need.</p><p class="abstract"><strong>Results: </strong>In this study, for majority (51%) patients &lt;12 weeks were in needed for union. Besides these, for 23.40% and 21.28% patients, time for union were 12-14 and &gt;14 weeks respectively. Unfortunately, in 4.26%% cases (n=2) incidence of non-union was occur. The mean period of radiological union was 12.75 weeks (12-16 weeks). Most of the patients were allowed complete weight bearing at 11 to 14 weeks. Average time gap for complete weight bearing was 13.5 weeks. In assessing the knee stability of the participants, we observed, the mean (±SD) angle of knee joints was 112.08 ±12.32 degree. The mean (±SD) Knee Society Score (KSS) was found 77.51 ± 8.16. As per the functional outcomes among all the participants, majority of them (57.45%) got ‘good’ results whereas 29.79% got ‘Excellent’ and 8.51% got ‘Poor’ results.</p><p class="abstract"><strong>Conclusions:</strong> Satisfactory knee joint stability for patients with tibial plateau fracture angular locking plate fixation technic may be considered as an effective treatment method for orthopedic surgeons. </p>

Use of a Portable Inertial Measurement Unit as an Evaluation Method for Supraspinatus Muscle: Proposed Normative Values

Treatment protocols do not specify an appropriate weight for rehabilitating the shoulder joint. The purpose of this study was to establish normative values for the shoulder abduction range of motion and recommended weights to be used in the rehabilitation process after injury to the supraspinatus muscle. Fifty-eight volunteers were assessed using the DyCare system. A test was conducted by lifting the arm to a 90° angle and having the participants lift different weights. The range of motion was similar for both sexes, suggesting that sex had no influence on this variable. Regarding the use of weights, men did not show as much stability in their movement execution, with a high dispersion seen in values between zero and three kilograms of weight, reaching a maximum weight of six kilograms. However, women showed good joint stability from the beginning of the test, with values that remained constant as weight increased up to a maximum of five kilograms. In conclusion, no major differences were observed in supraspinatus muscle injury recovery according to sex. However, differences were observed in the amount of weight that was necessary and appropriate to allow the participants to recover their muscular strength and avoid relapses.

Intraoperative Assessment of Gap Balancing in Total Knee Arthroplasty Using Navigation with Joint Stability Graphs

The purpose of this study was to assess continuous gaps in the replaced knee throughout the full range of motion (ROM) after total knee arthroplasty (TKA) using a joint stability graph, and to analyze the gap laxity in the mid-flexion range. Ninety-three TKAs were performed using imageless navigation with a joint stability graph. While positioning guides for each respective cut, the surgeon can safely preview the resection's impact for the resulting joint gaps and control the soft tissue balance at the knee flexion of 0° (extension) and 90° (flexion). The gaps between the femoral component and insert were evaluated throughout the full ROM using the joint stability graph. The mechanical axis (MA) and change of joint line height were radiographically evaluated. Posthoc power analyses using a significant α value of 0.05 were performed on the proportion of the mid-flexion instability as a primary outcome to determine whether the sample had sufficient power. The power was determined to be sufficient (100%). The flexion–extension gap differences in each medial and lateral compartment and the mediolateral gap differences in flexion and extension were all ≤3 mm. None of the knees had mid-flexion instability, which is defined by a peak mid-flexion gap that is 3 mm greater than the smaller value of flexion or extension gap. The average MA was well corrected from varus 11.4° to varus 1.0° postoperatively. The proportion of postoperative well-aligned knees (MA ≤ 3°) was 87.1%. The joint line height was well preserved (14.7 vs. 14.8 mm, p = 0.751). The joint stability graph in TKA using the navigation can effectively evaluate the continuous gap throughout the ROM, including the mid-flexion range. Mid-flexion instability was uncommon in primary TKAs with appropriate alignment and proper preservation of the joint line. The Level of evidence for the study is IV.

Testing Hypoxia in Pig Meniscal Culture: Biological Role of the Vascular-Related Factors in the Differentiation and Viability of Neonatal Meniscus

Menisci play an essential role in shock absorption, joint stability, load resistance and its transmission thanks to their conformation. Adult menisci can be divided in three zones based on the vascularization: an avascular inner zone with no blood supply, a fully vascularized outer zone, and an intermediate zone. This organization, in addition to the incomplete knowledge about meniscal biology, composition, and gene expression, makes meniscal regeneration still one of the major challenges both in orthopedics and in tissue engineering. To overcome this issue, we aimed to investigate the role of hypoxia in the differentiation of the three anatomical areas of newborn piglet menisci (anterior horn (A), central body (C), and posterior horn (P)) and its effects on vascular factors. After sample collection, menisci were divided in A, C, P, and they were cultured in vitro under hypoxic (1% O2) and normoxic (21% O2) conditions at four different experimental time points (T0 = day of explant; T7 = day 7; T10 = day 10; T14 = day 14); samples were then evaluated through immune, histological, and molecular analyses, cell morpho-functional characteristics; with particular focus on matrix composition and expression of vascular factors. It was observed that hypoxia retained the initial phenotype of cells and induced extracellular matrix production resembling a mature tissue. Hypoxia also modulated the expression of angiogenic factors, especially in the early phase of the study. Thus, we observed that hypoxia contributes to the fibro-chondrogenic differentiation with the involvement of angiogenic factors, especially in the posterior horn, which corresponds to the predominant weight-bearing portion.

Muscle Synergies in People With Chronic Ankle Instability During Anticipated and Unanticipated Cutting Tasks

Context: Although neuromuscular deficits in people with chronic ankle instability (CAI) have been identified, previous studies mostly investigated the activation of multiple muscles in isolation. Investigating muscle synergies in people with CAI would provide information about the coordination and control of neuromuscular activation strategies and could hold important information for understanding and rehabilitating neuromuscular deficits in this population. Objective: The purpose of this study was to investigate muscle synergies in people with CAI and healthy controls as they perform different cutting tasks. Design: Cross-sectional study Setting: Laboratory Participants: Eleven people with CAI (22 ± 3 years, 1.68 ± 0.11 m, 69.0 ± 19.1 kg) and 11 healthy controls (CON) (23 ± 4 years, 1.74 ± 0.11 m, 66.8 ± 15.5 kg) participated in the current study. Main Outcome Measures: Muscle synergies were extracted from the EMG of the soleus, medial gastrocnemius, lateral gastrocnemius, tibialis anterior, and fibularis longus muscles during anticipated and unanticipated cutting tasks. The number of synergies, activation coefficients, and muscle-specific weighting coefficients were compared between groups and across tasks. Results: The number of muscle synergies were the same for each group and task. The CAI group exhibited significantly greater (p = 0.023) tibialis anterior weighting coefficients within Synergy 1 compared to the CON group. In addition, both groups exhibited greater fibularis longus (p = 0.029) weighting coefficients within Synergy 2 during unanticipated cutting compared to anticipated cutting. Conclusion: These results suggest that while both groups used a neuromuscular control strategy of similar complexity / dimensionality to perform the cutting tasks, people with CAI exhibited different muscle-specific weightings characterized by greater emphasis on tibialis anterior function within Synergy 1, which may reflect an effort to increase joint stability to compensate for the presence of ankle instability.

Ligamentoplasty with interposition of the proximal interphalangeal joint in the treatment of unicondylar osteochondral defects: a cadaveric feasibility study

Background Injuries to the proximal interphalangeal (PIP) joint are common and complex. However, the treatment of osteochondral defects of the head of the proximal phalanx has rarely been described. Herein, we propose a new technique for the management of unicondylar defects of the proximal phalanx that can restore joint amplitudes and provide PIP stability.Methods In this cadaveric feasibility study, unicondylar defects were generated using striking wedges and chisels. First, a transverse tunnel measuring 2 mm in diameter passing through the head of the proximal phalanx was made. A second tunnel at the base of the middle phalanx with the same diameter was then created. The hemitendon of the flexor carpi radialis graft was passed through each of these tunnels. The proximal end of the graft was interposed in the area with a loss of bone substance. The ligamentoplasty was then tensed and fixed by two anchors on the proximal phalanx. Joint amplitudes and frontal stability were measured preoperatively and postoperatively.Results There was no significant change in the joint’s range of motion: preoperatively, the mean mobility arcs were –2° to 113.80°, and they were –2° to 110° after the procedure (P=0.999). There was no significant difference in joint stability (P>0.05).Conclusions Ligamentoplasty with PIP interposition appears to be a possible solution for the management of unicondylar defects of the proximal phalanx. An evaluation of clinical results is planned in order to definitively confirm the validity of this procedure.

Changes in muscle coactivation during running: a comparison between two techniques, forefoot vs rearfoot

Introduction: Surface electromyography has been a technique used to describe muscle activity during running. However, there is little literature that analyses the behaviour of muscle coactivation in runners, describing the effect between two techniques associated with the initial contact, such as the use of rearfoot (RF) and forefoot (FF). Material and method: The purpose of this study was to compare muscle coactivation levels developed in the lower limb during two running techniques, FF vs RF. Fourteen amateur runners were evaluated (eight men, six women; age= 23.21 ± 3.58 years, mass= 63.89 ± 8.13 kg, height= 1.68 ± 0.08m). Surface electromyography was used to measure muscle activity during both running techniques evaluated on a treadmill, considering the muscle pairs: Rectus femoris- Biceps femoris (RFe-BF), Lateral Gastrocnemius–Tibialis Anterior (LG-TA), and Medial Gastrocnemius - Tibialis Anterior (MG-TA). These were calculated in three windows considering ten running cycles (0-5%, 80-100%, and 0-100%). To compare FF vs RF t-student test for paired data was used. Results: It was observed significant differences in the MG-TA pair (FF= 18.42 ± 11.84% vs RF = 39.05 ± 13.28%, p = 0.0018 during 0-5%, and RFe-BF pair (FF = 42.38 ± 18.11% vs RF = 28.37 ± 17.2%, p = 0.0331) during 80-100% of the race. Conclusion: Our findings show that the behaviour of muscle coactivation is different between FF vs RF techniques if we analyze little windows in the running cycle. This could be associated with an increase in the joint stability between these short intervals, represented in the initial and final regions of the running cycle.