Abduction Angle Research Articles

Efficacy of the Ponseti method in the treatment of neglected idiopathic talipes equinovarus at a tertiary hospital in Nigeria

Objectives: Neglected clubfoot is common in our environment, for multifactorial reasons. It could cause pain and psychological distress to the patient and parents. We assessed the efficacy of the Ponseti method in the treatment of neglected clubfoot in a Nigerian Hospital. Material and Methods: This was a 15-month prospective and interventional study. Patients at least one-year-old with untreated idiopathic talipes equino varus (ITEV) or inadequately nonoperatively treated ITEV were the study population. The number of castings required for correction, tenotomy rate, dorsiflexion angle before and after tenotomy, and abduction angle after treatment were obtained. The chi-square test of independence was used to test the relationship between categorical variables. Logistic regression was used to assess if the Pirani score at the presentation predicted a successful correction at the end of the study. The level of significance was set at P < 0.05. Results: Forty-two children with 69 club feet were treated in this study. The mean age of presentation was 27.45 months (standard deviation [SD] = 19.22). The mean number of casting sessions required to achieve correction was 6.35 (SD = 1.95). The mean Pirani score at presentation was 4.27 (SD = 1.33) which reduced to 0.30 (SD = 0.35) after correction. The Pirani score at presentation had a positive correlation with the number of casts required for correction (r = 0.505, P < 0.001) but did not predict a successful correction after treatment. The success rate was 85.5%. Conclusion: The Ponseti method of treatment showed a high success rate in the treatment of neglected ITEV.

Relationship between increased knee joint line obliquity after medial open-wedge high tibial osteotomy and patient-reported outcome measures.

This study evaluated the correlation between postoperative knee joint line obliquity after medial open-wedge high tibial osteotomy and patient-reported outcome measures excluding excessively overcorrected knees. This study further identified preoperative radiological factors related to the increased postoperative knee joint line obliquity. We retrospectively evaluated patients who underwent medial open-wedge high tibial osteotomy between March 2013 and March 2021. Postoperative excessively overcorrected knees with hip-knee-ankle angle > 7° were excluded. We investigated radiological parameters and patient-reported outcome measures preoperatively and at the last follow-up. The following radiologic parameters were measured: hip-knee-ankle angle, weight-bearing line ratio, mechanical medial proximal tibial angle, mechanical lateral distal femoral angle, lateral distal tibial angle, joint line convergent angle, knee joint line obliquity, ankle joint line obliquity, hip abduction angle, tibial posterior slope, Carton-Deschamps index, and patella tilting angle. Clinical outcomes were evaluated using Japanese knee outcome measures. This assessment criterion is based on the Western Ontario McMaster Universities Arthritis Index and MOS Short Form 36. Multiple regression analysis was performed to evaluate the association between postoperative knee joint line obliquity and patient-reported outcome measures or preoperative radiological factors (P < .05). A total of 52 knees were included. The mean age at the time of the surgery was 61.6 ± 9.0years and the mean follow-up period was 30.6 ± 10.1months. Increased postoperative knee joint line obliquity was associated with lower Japanese knee outcome measures. The preoperative hip-knee-ankle angle was significantly associated with postoperative knee joint line obliquity. Increased knee joint line obliquity after medial open-wedge high tibial osteotomy is associated with inferior clinical outcomes. Care should be given to the center of the rotational angulation in around-knee osteotomy to avoid postoperative increased knee joint line obliquity. Retrospective comparative study, Level III.

A 2D video-based assessment is associated with 3D biomechanical contributors to dynamic knee valgus in the coronal plane.

Adolescent athletes involved in sports that involve cutting and landing maneuvers have an increased risk of anterior cruciate ligament (ACL) tears, highlighting the importance of identifying risky movement patterns such as dynamic knee valgus (DKV). Qualitative movement screenings have explored two-dimensional (2D) scoring criteria for DKV, however, there remains limited data on the validity of these screening tools. Determining a 2D scoring criterion for DKV that closely aligns with three-dimensional (3D) biomechanical measures will allow for the identification of poor knee position in adolescent athletes on a broad scale. The purpose of this study was to establish a 2D scoring criterion that corresponds to 3D biomechanical measures of DKV. A total of 41 adolescent female club volleyball athletes performed a three-task movement screen consisting of a single-leg squat (SLS), single-leg drop landing (SLDL), and double-leg vertical jump (DLVJ). A single rater scored 2D videos of each task using four criteria for poor knee position. A motion capture system was used to calculate 3D joint angles, including pelvic obliquity, hip adduction, knee abduction, ankle eversion, and foot progression angle. Receiver operating characteristic curves were created for each 2D scoring criterion to determine cut points for the presence of movement faults, and areas under the curve (AUC) were computed to describe the accuracy of each 2D criterion compared to 3D biomechanical data. 3D measures indicated knee abduction angles between 2.4°-4.6° (SD 4.1°-4.3°) at the time point when the center of the knee joint was most medial during the three tasks. AUCs were between 0.62 and 0.93 across scoring items. The MEDIAL scoring item, defined as the knee joint positioned inside the medial border of the shoe, demonstrated the greatest association to components of DKV, with AUCs ranging from 0.67 to 0.93. The MEDIAL scoring criterion demonstrated the best performance in distinguishing components of DKV, specifically pelvic obliquity, hip adduction, ankle eversion, and foot progression. Along with the previously published scoring definitions for trunk-specific risk factors, the authors suggest that the MEDIAL criterion may be the most indicative of DKV, given an association with 3D biomechanical risk factors.

Analysis of the stress-strain state of a three-dimensional model a shoulder hemiarthroplasty after changing the greater tubercle position on the shoulder

Background. The greater tubercle position change in shoulder hemiarthroplasty is of great importance for the shoulder joint contact surfaces’ stress-strain state (SТS). One of the important conditions for restoring a full range of motion in the shoulder joint after hemiarthroplasty and a longer service life of the endoprosthesis is the anatomical location of the greater tubercle. The purpose was to develop a three-dimensional model and study the STS of elements of the shoulder joint and implants of a hemiarthroplasty after changing the greater tubercle position on the shoulder. Materials and methods. The SolidWorks software package was used in order to construct a simulated 3D model of the shoulder joint, taking anatomical and anthropometric data into conside­ration to make the model as close to the real shoulder joint as possible. The ANSYS software package was used to calculate the shoulder joint models of the total load vector at different positions of the total load vector, depending on the greater tubercle of the humerus position. Results. The analysis of the shoulder joint mo­del elements’ STS with different greater tuberosity positioning and a shoulder abduction angle of 60° showed that the maximum increase in stress values is observed on the glenoid cavity subchondral bone when the greater tubercle of the humerus is transposed by 1 cm anterior — in 3.4 times, σmax up to 4.02 MPa. Moving the big tubercle by 1 cm distally is an optimal position in which the subchondral bone of the glenoid cavity undergoes minimum stress and deformation forces. Conclusions. The change in pressure on the contact surfaces is significant when changing the position of the greater tuberosity, which will undoubtedly affect the volume and range of motion in the postoperative period. Taking into account the data of the stress values on the contact surfaces obtained from our simula­ted 3D computer model of the shoulder joint allows improving the quality of preoperative planning and improving shoulder function and possible complications in the postoperative period.

Knee Joint Line Obliquity With Adaptational Hip and Ankle Joint Orientation After Medial Open Wedge High Tibial Osteotomy

Background: Time-dependent postoperative changes in knee joint line obliquity (KJLO) and subsequent adaptational changes in the hip and ankle joints have not been fully proven after medial open wedge high tibial osteotomy (MOWHTO). Purpose: To investigate the serial postoperative changes in KJLO and subsequent adaptational changes in the hip and ankle joints over time after MOWHTO. Study design: Case series, Level of evidence, 4. Methods: A total of 92 patients who underwent MOWHTO between April 2015 and December 2020 were evaluated. Radiographic parameters, including KJLO, ankle joint line obliquity (ALO), hip abduction angle (HAA), joint line convergence angle, weightbearing line ratio, and hip-knee-ankle angle, were analyzed in time sequence (preoperatively and 3, 6, 12, and 24 months postoperatively). Repeated-measures analysis of variance and post hoc analysis were used to demonstrate alterations and the statistical significance of KJLO and other related radiographic parameters over time. Results: The mean KJLO values were –1.9°, –2.1°, –2.7°, and –3.2° at 3, 6, 12, and 24 months postoperatively, respectively, indicating that there was consistent increase in valgus tilting of KJLO from 6 to 24 months (P < .001 for both 6-12 months and 12-24 months). ALO and HAA showed significant changes from 6 to 12 months (ALO, P < .001; HAA, P = .002), but not between 12 and 24 months (ALO: –3.0°, –2.7°, –1.9°, and −1.6°; HAA: –0.8°, –0.9°, –1.5°, and −1.8° at 3, 6, 12, and 24 months, respectively). The mean joint line convergence angle, weightbearing line ratio, and hip-knee-ankle angle did not change significantly from 3 months to 24 months postoperatively. Conclusion: There was a consistent increase in valgus tilting of the postoperative KJLO from 6 to 24 months after MOWHTO. The adaptive ALO and HAA significantly changed between 6 and 12 months and were maintained until 24 months after MOWHTO. It is necessary to consider the adaptive change when hip or ankle surgery is planned within this period.

Knee Biomechanics During Cutting Maneuvers and Secondary ACL Injury Risk: A Prospective Cohort Study of Knee Biomechanics in 756 Female Elite Handball and Soccer Players.

An athlete who returns to sport after an anterior cruciate ligament (ACL) injury has a substantially high risk of sustaining a new secondary ACL injury. Because ACL injuries most frequently occur during cutting maneuvers, such movements should be at the center of research attention. To investigate whether knee biomechanical parameters during side-step cutting maneuvers differ between female elite athletes with and without a history of ACL injury and to evaluate whether such parameters are associated with future secondary ACL injury. Cohort study; Level of evidence, 2. A total of 756 female elite handball and soccer players, of whom 76 had a history of ACL injury, performed a sport-specific cutting task while 3-dimensional kinematics and kinetics were measured. ACL injuries were registered prospectively over an 8-year follow-up period. Seven knee-specific biomechanical variables were the basis for all analyses. Two-way analyses of variance were applied to assess group differences, whereas logistic regression models served to evaluate associations between the knee-specific variables and future secondary ACL injury. When players with a previous ACL injury performed the cutting maneuver with their ipsilateral leg, they exhibited lower knee abduction angles (mean difference [MD], 1.4°-1.5°; 95% CI, 0.2°-2.9°), lower peak knee flexion moments (MD, 0.33 N·m/kg-1; 95% CI, 0.18-0.48 N·m/kg-1), lower peak knee abduction moments (MD, 0.27 N·m/kg-1; 95% CI, 0.12-0.41 N·m/kg-1), and lower peak knee internal rotation moments (MD, 0.06 N·m/kg-1; 95% CI, 0.01-0.12 N·m/kg-1) compared with injury-free players. When players performed the cut with their contralateral leg, no differences were evident (P < .05). None of the 7 knee-specific biomechanical variables was associated with future secondary ACL injury in players with an ACL injury history (P < .05). Approximately 4 years after ACL injury, female elite team-ball athletes still unloaded their ipsilateral knee during cutting maneuvers, yet contralateral knee loading was similar to that of injury-free players. Knee biomechanical characteristics were not associated with future secondary ACL injury.

Personalized digital simulation‑assisted acetabular component implantation in revision hip arthroplasty.

The number of artificial total hip revision arthroplasties is increasing yearly in China, and >50% of these cases have acetabular defects. Accurately locating and quantifying the bone defect is one of the current challenges of this surgery. Thus, the objective of the present study was to simulate acetabular implantation with the aid of Mimics 17.0 software (Materialise NV) in patients with loosened acetabular prosthesis, to evaluate the 'ideal acetabular center' and the 'actual acetabular center' to guide the choice of prosthesis and surgical method. From January 2017 to June 2021, the present study included 10 hips from 10 patients [seven men (seven hips) and three women (three hips)]. In all patients, the Mimics software was applied to simulate the dislocation of the femoral prosthesis and acetabular prosthesis implantation before surgery; calculate the height difference between the 'ideal acetabular center' and the 'actual acetabular center' to assess the bone defect; confirm the size of the acetabular prosthesis, abduction angle, anteversion angle and bone coverage of the acetabular cup; and measure the intraoperative bleeding and postoperative follow-up Harris score of the hip joint. After statistical analysis, the present study revealed that digital simulation assistance could improve the accuracy of hip revision acetabular prosthesis implantation, reduce postoperative shortening of the affected limb, especially for surgeons with relatively little experience in hip revision surgery, and greatly reduce the occurrence of complications such as hip dislocation because of poor postoperative prosthesis position.

Influence of Torsional Stiffness in Badminton Footwear on Lower Limb Biomechanics.

Torsional stiffness of athletic footwear plays a crucial role in preventing injury and improving sports performance. Yet, there is a lack of research focused on the biomechanical effect of torsional stiffness in badminton shoes. This study aimed to comprehensively investigate the influence of three different levels of torsional stiffness in badminton shoes on biomechanical characteristics, sports performance, and injury risk in badminton players. Fifteen male players, aged 22.8 ± 1.96 years, participated in the study, performing badminton-specific tasks, including forehand clear stroke [left foot (FCL) and right foot (FCR)], 45-degree sidestep cutting (45C), and consecutive vertical jumps (CVJ). The tasks were conducted wearing badminton shoes of torsional stiffness measured with Shore D hardness 50, 60, and 70 (referred to as 50D, 60D, and 70D, respectively). The primary biomechanical parameters included ankle, knee, and MTP joint kinematics, ankle and knee joint moments, peak ground reaction forces, joint range of motion (ROM), and stance time. A one-way repeated measures ANOVA was employed for normally distributed data and Friedman tests for non-normally distributed data. The 70D shoe exhibited the highest ankle dorsiflexion and lowest ankle inversion peak angles during 45C task. The 60D shoe showed significantly lower knee abduction angle and coronal motions compared to the 50D and 70D shoes. Increased torsional stiffness reduced stance time in the FCR task. No significant differences were observed in anterior-posterior and medial-lateral ground reaction forces (GRF). However, the 70D shoe demonstrated higher vertical GRF than the 50D shoe while performing the FCR task, particularly during 70% - 75% of stance. Findings from this study revealed the significant role of torsional stiffness in reducing injury risk and optimizing performance during badminton tasks, indicating that shoes with an intermediate level of stiffness (60D) could provide a beneficial balance between flexibility and stability. These findings may provide practical references in guiding future badminton shoe research and development. Further research is necessary to explore the long-term effects of altering stiffness, considering factors such as athletic levels and foot morphology, to understand of the influence of torsional stiffness on motion biomechanics and injury prevalence in badminton-specific tasks.

Effect of stump-preserving repair on rotator cuff healing and shoulder function for degenerative total rotator cuff tears

To analyze the effect of stump-preserving repair on rotator cuff healing and shoulder function for degenerative total rotator cuff tears. A clinical data of 152 patients with degenerative total rotator cuff tears, who underwent arthroscopic repair between April 2019 and May 2022, was retrospectively analyzed. There were 76 males and 76 females with an average age of 55.4 years (range, 24-78 years). MRI was performed at 6 months postoperatively to evaluate the rotator cuff healing according to the Sugaya classification. Pre- and intra-operative related factors were included for univariate analysis, including age (≥60 years/<60 years), gender (male/female), passive activity disorder (yes/no), disease duration (≤3 months/>3 months), stump-preserving repair (yes/no), use of suture bridge technique (yes/no), shoulder joint abduction angle at knotting (<45°/≥45°), acromioplasty (yes/no), glucocorticoid injection (yes/no), time for patients to start postoperative passive exercise (≤2 weeks/>2 weeks), and time for patients to start postoperative active exercise (≤3 months/>3 months). The influencing factors of tendon healing were screened; further logistic regression was used to conduct multivariate analysis to screen for risk factors. Two sets of data were balanced by propensity score matching. The American Shoulder and Elbow Surgeons (ASES) score and Constant-Murley score of shoulder joint function at 6 and 12 months postoperatively, as well as rotator cuff healing rate at 6 months postoperatively, were compared between groups based on whether or not stump-preserving repair was used. All patients were followed up 12-33 months (mean, 23.8 months). MRI at 25-31 weeks postoperatively showed the 121 cases of rotator cuff healing and 31 cases of non healing. Univariate analysis showed that the disease duration, stump-preserving repair, shoulder joint abduction angle at knotting, and the time for patients to start postoperative active exercise were the influencing factors of rotator cuff healing ( P<0.05). Multivariate analysis showed that non-stump-preserving repair, shoulder abduction angle more than 45° at knotting, and the time to start active exercise within 3 months postoperatively were risk factors affecting rotator cuff healing ( P<0.05). A total of 51 pairs of cases were matched based on the grouping criteria of whether the disease duration exceeded 3 months, whether the shoulder abduction angle at knotting exceeded 45°, and whether the time to start postoperative active exercise exceeded 3 months. The rotator cuff healing rate, ASES score, and Constant-Murley score of the preserving repair group at 6 months postoperatively were superior to those of the non-preserving repair group, and the differences were significant ( P<0.05). There was no significant difference in ASES score and Constant-Murley score between the two groups at 12 months postoperatively ( P>0.05). For degenerative total rotator cuff tears, the stump-preserving repair can shorten the healing time and promote the shoulder function recovery, but has no significant effect on shoulder function at 1 year postoperatively.

A mixed reality application for total hip arthroplasty

Total hip arthroplasty (or total hip replacement) is the current surgical solution for the treatment of advanced coxarthrosis, with the objective of providing mobility and pain relief to patients. For this purpose, surgery can be planned using preoperative images acquired from the patient and navigation systems can also be used during the intervention. Robots have also been used to assist in interventions. In this work, we propose a new mixed reality application for total hip arthroplasty. The surgeon only has to wear HoloLens 2. The application does not require acquiring preoperative or intraoperative images of the patient and uses hand interaction. Interaction is natural and intuitive. The application helps the surgeon place a virtual acetabular cup onto the patient's acetabulum as well as define its diameter. Similarly, a guide for drilling and implant placement is defined, establishing the abduction and anteversion angles. The surgeon has a direct view of the operating field at all times. For validation, the values of the abduction and anteversion angles offered by the application in 20 acetabular cup placements have been compared with real values (ground-truth). From the results, the mean (standard deviation) is 0.375 (0.483) degrees for the error in the anteversion angle and 0.1 (0.308) degrees for the abduction angle, with maximum discrepancies of 1 degree. A study was also carried out on a cadaver, in which a surgeon verified that the application is suitable to be transferred to routine clinical practice, helping in the guidance process for the implantation of a total hip prosthesis.

Comparison of the Post Treatment Outcomes of a Conservative Physiotherapy Protocol for Subacromial Impingement Syndrome in Terms of Acromion Morphology

Objective: The present study aimed to compare the results of a conservative physiotherapy (CP) protocol for subacromial impingement syndrome (SIS) in terms of the morphological types of acromion. Methods: Fifty patients participated in the present study, and they were divided into 3 groups according to the acromion morphology types. A 8-week CP (4-week treatment period at the clinic and, in addition, an exercise program at home for 4 weeks) was applied to all patients. The patients were evaluated in terms of pain (at rest and activity) by the Visual Analog Scale, range of motion (ROM), joint position sense (laser pointer), muscle strength (digital dinamometer), and functionality (the Shoulder Pain and Disability Index, SPADI) before and after the treatment. Result: In the pre- and post-treatment changes (delta), the shoulder flexion angle increased less in the type 3 group than in the type 1 and type 2 groups (p&lt;0.05). In the shoulder abduction angle, there was a similar increase in the type 3 group compared to the type 2 group, while there was less increase in the type 1 group (p&lt;0.05). It was determined that there was more deviation in the change value of shoulder abduction position sense in the type 3 group compared to the other groups (p&lt;0.05). There was no difference between the groups in the change values of pain, muscle strength, or the SPADI score (p &gt; 0.05). Conclusion: Type 3 acromion may have a handicap in improving shoulder flexion and abduction ROM and shoulder abduction position compared to other types.

An 8-week injury prevention exercise program combined with change-of-direction technique training limits movement patterns associated with anterior cruciate ligament injury risk

Knee ligament sprains are common during change-of-direction (COD) maneuvers in multidirectional team sports. This study aimed to compare the effects of an 8-week injury prevention exercise program containing COD-specific exercises and a similar program containing linear sprint exercises on injury- and performance-related variables during a 135° COD task. We hypothesized that the COD-specific training would lead to (H1) stronger reductions in biomechanical variables associated with anterior cruciate ligament (ACL) injury risk during COD, i.e. knee abduction moment and angle, hip internal rotation angle and lateral trunk lean, and (H2) more effective improvements in COD performance according to the COD completion time, executed angle, ground contact time, and approach speed. Twenty-two sports science students (40% female) completed biomechanical assessments of COD movement strategies before and after participating in two supervised 25-min training sessions per week over 8 weeks. We observed significant ‘training x group’ interaction effects in support of H1: the COD-specific training but not the linear sprint training led to reduced peak knee abduction moments (interaction, p = 0.027), initial knee abduction (interaction, p < 0.001), and initial lateral trunk lean angles (interaction, p < 0.001) compared to baseline. Although the COD-specific training resulted in sharper executed angles (interaction, p < 0.001), the sprint-specific training group showed reduced COD completion (interaction, p = 0.037) and ground contact times (interaction, p < 0.001). In conclusion, a combination of generic and COD-specific injury prevention training resulted in COD technique adaptations that can help to avoid ACL injury-prone COD movements but may negatively affect COD speed.

Association of Range of Motion Deficit and Recurrence of Pain After Treatment of Adhesive Capsulitis.

We evaluated the factors influencing the duration of significant pain reduction after conservative management for adhesive capsulitis (AC). Follow-up for 6-8months was performed with 141 patients with AC who experienced significant pain reduction after treatment. Clinical and demographic factors, numeric rating scale (NRS) scores, and shoulder range of motion (ROM) were collected and assessed pretreatment (T0), at 5weeks post-treatment (T1), and at 6-8months post-treatment (T2). Patients were divided into successful (n = 96) and unsuccessful (n = 45) NRS groups according to the degree of pain reduction at T2. We assessed post-treatment NRS and ROM improvement scores within each group and compared these parameters between the two groups. Significant NRS and ROM improvements were achieved in all patients who participated in our study. The unsuccessful NRS group demonstrated a lack of significant improvement in abduction at T1 and T2. All T1 and shoulder ROM measurements among the unsuccessful NRS group were significantly smaller than those among the successful NRS group. Failure to achieve a significant improvement in abduction angle after conservative management of AC was significantly associated with pain recurrence.

Biomechanical evaluation of screw and cement placement strategies for treating medial uncontained tibial defects in total knee arthroplasty: A finite element analysis.

Total knee arthroplasty faces challenges in the management of medial uncontained tibial defects, affecting prosthesis stability and implant survival. The use of screws and bone cement is a preferred approach; however, optimal screw insertion techniques lack consensus in the existing literature. The present study aimed to address this gap by exploring optimal screw and cement placement strategies, focusing on their biomechanical implications. The present study conducted a finite element analysis using a knee prosthesis model with a defined uncontained tibial defect. Various parameters were systematically adjusted, including the number of screws (1, 2 or 3 screws), screw lengths (10, 18, 30 or 40 mm), lateral-medial screw positions (2, 4 or 6 mm laterally) and abduction rotation angles (0, 5, 10 or 15 degrees). These adjustments were made to evaluate their specific and combined impacts on the vertical displacement and abduction angles of the tibial tray. The results revealed that incorporating three-screw reinforcement markedly reduced vertical displacement, while the single screw in the middle position exhibited superior performance in preventing the deformation of abduction angles compared to scenarios with two screws at anterior and posterior positions without a middle screw. Longer screws and smaller abduction angles contributed to decreased movement of the tibial component. Furthermore, the lateral adjustment of the screw position led to an increase in vertical displacement values, reaching ~1.5% when shifted 6 mm laterally. On the whole, the finite element analysis in the present study suggests that, for the treatment of medial uncontained tibial defects, three-screw reinforcement is advantageous for larger defects. Longer screws and a smaller abduction angle are deemed favorable. Moreover, the results underscore the superiority of medial screw placement over lateral placement. It is imperative to note that further clinical validation is essential to corroborate the biomechanical implications observed herein.

Postoperative Maintenance of Sagittal Plane Positioning of the First Metatarsophalangeal Joint After Arthrodesis with an Isolated Dorsal Plate Construct: A Retrospective Review of 43 Feet.

First metatarsophalangeal joint arthrodesis with isolated dorsal plating without a lag screw and without a compressive mechanism incorporated into the plate is not well studied. Although surface area for bony fusion is increased, there is concern for lower fusion rates and progressive loss of sagittal plane positioning. We present fusion rates and progressive sagittal plane deviation with isolated dorsal plate fixation. A retrospective review was performed of 41 patients (43 feet) who underwent first metatarsophalangeal joint arthrodesis with isolated dorsal plate fixation. Patients were excluded if another form of fixation was used, if there was a compressive feature to the dorsal plate, or if a lag screw was used. Preoperative, immediate postoperative, and final postoperative radiographs were reviewed to assess radiographic alignment and fusion about the first metatarsophalangeal joint. Specific attention was placed on hallux dorsiflexion in relation to the first metatarsal. Statistical significance was set at P ≤ .05 a priori. Patients were followed for an average of 55.7 weeks. Overall union rate was 97.62%. The average time to union was 42.55 days. Reoperation rate was 4.65%, with one patient requiring revisional arthrodesis with a lag screw construct. Hallux abduction and first-second intermetatarsal angle correction reached significance (P < .00001). Hallux dorsiflexion increased by 1.05° between initial postoperative and final postoperative radiographs (P = .542). Although fusion rates and progressive loss of sagittal plane position have been concerns for first metatarsophalangeal joint arthrodesis with an isolated dorsal plate construct, these results suggest this to be a stable construct without loss of positioning over time.

Anterior Latissimus Dorsi Transfer for Irreparable Subscapularis Tears Improves Shoulder Kinematics in a Dynamic Biomechanical Cadaveric Shoulder Model

Background: In young patients with irreparable subscapularis deficiency (SSC-D) and absence of severe osteoarthritis, anterior latissimus dorsi transfer (aLDT) has been proposed as a treatment option to restore the anteroposterior muscular force couple to regain sufficient shoulder function. However, evidence regarding the biomechanical effect of an aLDT on glenohumeral kinematics remains sparse. Purpose/Hypothesis: The purpose of this study was to investigate the effects of an aLDT on range of glenohumeral abduction motion, superior migration of the humeral head (SM), and cumulative deltoid force (cDF) in a simulated SSC-D model using a dynamic shoulder model. It was hypothesized that an aLDT would restore native shoulder kinematics by reestablishing the insufficient anteroposterior force couple. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric shoulders were tested using a validated shoulder simulator. Glenohumeral abduction angle (gAA), SM, and cDF were compared across 3 conditions: (1) native, (2) SSC-D, and (3) aLDT. gAA and SM were measured using 3-dimensional motion tracking, while cDF was recorded in real time during dynamic abduction motion by load cells connected to actuators. Results: The SSC-D significantly decreased gAA (Δ–9.8°; 95% CI, –14.1° to −5.5°; P < .001) and showed a significant increase in SM (Δ2.0 mm; 95% CI, 0.9 to 3.1 mm; P = .003), while cDF was similar (Δ7.8 N; 95% CI, –9.2 to 24.7 N; P = .586) when compared with the native state. Performing an aLDT resulted in a significantly increased gAA (Δ3.8°; 95% CI, 1.8° to 5.7°; P < .001), while cDF (Δ–36.1 N; 95% CI, –48.7 to −23.7 N; P < .001) was significantly reduced compared with the SSC-D. For the aLDT, no anterior subluxation was observed. However, the aLDT was not able to restore native gAA (Δ–6.1°; 95% CI, –8.9° to −3.2°; P < .001). Conclusion: In this cadaveric study, performing an aLDT for an irreparable subscapularis insufficiency restored the anteroposterior force couple and prevented superior and anterior humeral head migration, thus improving glenohumeral kinematics. Furthermore, compensatory deltoid forces were reduced by performing an aLDT. Clinical Relevance: Given the favorable effect of the aLDT on shoulder kinematics in this dynamic shoulder model, performing an aLDT may be considered as a treatment option in patients with irreparable SSC-D.

Insufficient stem antetorsion and lower cup abduction is a combined risk factor for posterior hip dislocation in patients undergoing THA for femoral neck fractures: a retrospective analysis

BackgroundThe role of acetabular and femoral component positions with respect to the risk of post-operative instability and dislocation remains debated. In this study, we aimed to identify potential risk factors for early dislocation following primary total hip arthroplasty (THA) for displaced intracapsular femoral neck fractures (FNF) using radiological measurements.MethodsWe retrospectively analyzed data for patients who underwent cementless primary THA for FNF using a posterolateral approach between January 2018 and December 2021. Follow-up duration, age, sex, affected side, and mean time from THA to dislocation were recorded. Leg-length inequality, abductor lever arm, vertical and horizontal femoral offsets, vertical and horizontal hip centers of rotation, abduction, anteversion of the acetabulum and femoral prosthesis, and combined anteversion were measured.ResultsThe study sample included 17 men and 34 women, with 21 and 30 patients undergoing left- and right-hip operations, respectively. The mean patient age was 70.18 ± 7.64 years, and the mean follow-up duration was 27.73 ± 13.52 months. The mean time between THA and dislocation was 1.58 ± 0.79 months. Seven patients (13.73%) sustained posterior dislocation of the hip. The abduction angle (36.05 ± 6.82° vs. 45.68 ± 8.78°) (p = 0.008) and anteversion of the femoral prosthesis (8.26 ± 4.47° vs. 19.47 ± 9.01°) (p = 0.002) were significantly lower in the dislocation group than in the control group. There were no significant differences in other parameters.ConclusionsInsufficient stem antetorsion combined with lower abduction angle of the acetabular component were associated with a high risk of dislocation, especially in patients with deep flexion or internal rotation of the flexed hip joint and knees, or in patients with a stiff spine or anterior pelvic tilt, impingement may then occur in the neck of the prosthesis and cup component, ultimately resulting in posterior dislocation. These findings could remind surgeons to avoid simultaneous occurrence of both in THA surgery. These results provide new insight into risk factors for hip dislocation in patients undergoing primary THA for FNF and may aid in reducing the risk of instability and dislocation.Level of evidenceProspective comparative study Level II.

Acellular Human Dermal Allograft Tuberoplasty Improved the Biomechanics in Mid-Range and Higher Abduction Angles in a Cadaveric Model of Massive Irreparable Rotator Cuff Tears

PurposeTo evaluate the biomechanical effects of Acellular Human Dermal Allograft Tuberoplasty (AHDAT) in a cadaveric model of an irreparable supraspinatus + anterior ½ infraspinatus (Stage III) rotator cuff tear . MethodsEight cadaveric shoulders were tested at 20°, 40°, and 60° glenohumeral abduction (AB) and 0°, 30°, 60°, and 90° external rotation (ER). Superior humeral translation, acromiohumeral distance, and subacromial contact were quantified for four conditions: 1) intact, 2) stage III tear (entire supraspinatus and anterior one-half infraspinatus), 3) single-layer AHDAT, and 4) double-layer AHDAT. ResultsStage III tear significantly increased superior translation at 20° and 40°AB and all ER angles and at 60° AB/60° ER (P ≤ 0.045 vs. intact). Compared to the stage III tear, the single-layer AHDAT significantly decreased superior translation at 60° AB/60° ER (P = 0.003); whereas, the double-layer AHDAT significantly decreased superior translation at 40° and 60° AB at all ER angles except 60° AB/0° ER (P ≤ 0.028). The stage III tear significantly decreased acromiohumeral distance at 20° AB (P ≤ 0.003); both grafts increased acromiohumeral distance to intact levels(P ≥ 0.055 vs. intact). Stage III tear increased subacromial contact pressure at 20° and 40° AB/ 0° and 30° ER and at 60° AB/30° and 60° ER (P ≤ 0.034). Both AHDAT groups decreased contact pressure at 40° AB/30° and 60° ER back to intact; whereas the double-layer AHDAT also decreased contact pressure at 20° AB/0° and 60° ER and 60° AB/30° ER (P ≥ 0.051 vs. intact). ConclusionBoth single- and double- layer grafts for AHDAT, improved superior translation, subacromial contact characteristics and acromiohumeral distance after a stage III rotator cuff tear, with varying effectiveness due to the position-dependent nature of greater tuberosity-to-acromial contact with abduction.

What Is the Revision-free Survival of Resurfaced Allograft-prosthesis Composites for Proximal Humerus Reconstruction in Children With Bone Tumors?

What Is the Revision-free Survival of Resurfaced Allograft-prosthesis Composites for Proximal Humerus Reconstruction in Children With Bone Tumors?

Examining the joint coordination during dynamic balance learning using vector coding and statistical parametric mapping analyses

We aimed to examine the changes in balance performance, kinematic variables, and joint coordination of the lower extremities during the Y-balance learning task. Twenty female university students completed five consecutive blocks of Y-balance learning from days 3 to 7 (135 trials). Pre-tests and tests were performed on days 1 and 9. Maximum reach distance, peak joint angle, and joint coordination in the anterior (AL), posterolateral (PL), and posteromedial (PM) directions were measured to determine the efficacy of Y-balance performance. A repeated measures ANOVA was performed for the maximum reach distance across learning blocks to confirm whether learning had occurred. Our results indicated that the maximum reach distance on day 5 was longer than that on other learning days. The maximum reach distance significantly increased in the PL and PM directions after learning. The hip flexion (PL/PM), abduction (PM), internal rotation (PM), and external rotation (PL) angles increased after learning. The knee joint flexion angle increased in both AL and PL directions. Only the ankle dorsiflexion angle increased in the AL direction. Joint coordination indicated that the knee and hip joints performed simultaneously during internal rotation. Ankle-knee joint coordination was performed using dorsiflexion and flexion strategies. Statistical parametric mapping analysis indicated significant differences in the ankle sagittal plane in the AL direction, hip horizontal and hip/knee sagittal planes in the PL direction, and hip/knee sagittal and hip frontal/horizontal planes in the PM direction. These data suggest that the dynamic balance ability of the novice participants improved in relation to changes in coordination patterns after learning. The results of this study can be applied to other populations to improve their dynamic balance and prevent fall injuries.