Pre-operative gluteus medius tendon degeneration and its impact on strength and functional ability one year after total hip replacement.

OBJECTIVE: Hip osteoarthritis is a common cause of disability and surgery is often unavoidable. Patient satisfaction is high and functional ability improves after surgery. However, residual impairment and pain are common. Degenerative changes in tendons and muscles are probable causes. The aim of this study is to investigate gluteus medius (GMED) tendon degeneration in relation to muscle strength, physical function and walking distance before and one year after total hip replacement. MATERIAL AND METHODS: In total, 18 patients were examined pre- and post-operatively, of whom 15 were available in the final analysis. Muscle strength, physical function and walking distance were assessed. Tendon biopsies were assessed microscopically, and the total degeneration score (TDS) was calculated. RESULTS: A correlation between the TDS and muscle strength was found for the hamstrings, GMED and quadriceps pre- or post-operatively. No correlations were found between the TDS and functional ability. Functional ability and muscle strength improved significantly after surgery. CONCLUSION: Our results indicate a correlation between tendon degeneration and the muscle strength of the hip and knee in patients with hip OA and one year after THR. To minimise post-operative residual discomfort, rehabilitation programs should probably be modified over time to match the pre- and post-operative needs. Further studies are needed.This study was registered at https://www.researchweb.org/is/vgr/project/279039 (in Swedish).

There are negative correlations, which suggest patterns between degeneration in the GMED tendon and muscle strength in the muscles acting around the hip in patients with hip OA, before and after THR.The strength training of muscles acting around the hip joint may need to be adjusted before and after THR.

[Arthroscopic surgery for injuries to the popliteal tendon area of the lateral meniscus].

OBJECTIVE: To investigate the mid-term effect and complications of arthroscopic popliteal tendon suture in the treatment of lateral meniscus injury. METHODS: From January 2016 to December 2020, the data of 57 patients with lateral meniscus popliteal tendon injury treated by arthroscopic popliteal tendon suture fixation were retrospectively analyzed, including 35 males and 22 females, aged from 18 to 47 years old with an average of (32.9±7.9) years old. Knee function was evaluated using the International Knee Documentation Committee (IKDC) and Lysholm scores both before the operation and at the final follow-up. Meniscus healing was evaluated according to the postoperative Barrett standard. Wound healing complications, such as vascular injury, nerve injury, and lower extremity venous thrombosis, were recorded. RESULTS: All 57 patients were followed up for 12 to 58 months with an average of (38.1±14.9) months.The incisions of the patients after the operation were all Grade A healing without infection, popliteal tendon injury, blood vessel injury, nerve injury and lower extremity venous thrombosis.The IKDC score increased from (49.7±3.6) points preoperatively to (88.5±4.4) points in the final follow-up (P<0.05). The Lysholm score increased from (48.8±4.9) points preoperatively to (91.9±3.9) points at the final follow-up (P<0.05). At 3, 6 months and 1 year after operation, according to Barrett's criteria, 54 cases were clinically healed, the healing rate was 94.7% (54/57). CONCLUSION: This study preliminarily confirmed that arthroscopic suture technique can result in clinical stability through suture and fixation of the meniscus in the injured lateral popliteal tendon area. No adverse effects on knee joint function were found in the mid-term follow-up after the operation.

Design and Research of the Grasping Force Feedback Mechanism of Flexible Surgical Robots.

BACKGROUND: Robot-assisted microsurgery (RAMS) is gradually becoming the preferred method for some delicate surgical procedures. However, the lack of haptic feedback reduces the safety of the surgery. Surgeons are unable to feel the grasping force between surgical instruments and the patient's tissues, which can easily lead to grasping failure or tissue damage. METHODS: This paper proposes a tendon-driven grasping force feedback mechanism, consisting of a follower hand and a leader hand, to address the lack of grasping force feedback in flexible surgical robots. Considering the friction in the tendon transmission process, a grasping force estimation model is established for the follower hand. The admittance control model is designed for force/position control of the leader hand. RESULTS: Through experimental validation, it has been confirmed that the grasping force sensing range of the follower hand is 0.5-5 N, with a sensing accuracy of 0.3 N. The leader hand is capable of providing feedback forces in the range of 0-5 N, with a static force accuracy of 0.1 N. CONCLUSIONS: The designed mechanism and control strategy can provide the grasping force feedback function. Future work will focus on improving force feedback performance. TRIAL REGISTRATION: This research has no clinical trials.

Comparative analysis of pain outcomes in hypoglossal nerve stimulation: Avoiding the digastric tendon.

OBJECTIVE: Upper airway stimulation effectively treats patients with obstructive sleep apnea, especially among those with low long-term compliance with continuous positive airway pressure. Traditional methods to implant the hypoglossal nerve stimulator involve retraction of the digastric tendon to identify the nerve and improve exposure for stimulator implantation. Transient submental pain and discomfort are known side effects of the procedure. Placement without retraction provides an alternative approach to minimize postoperative pain. This study compares post-operative pain outcomes of patients in whom the digastric tendon was and was not retracted. METHODS: Retrospective chart review of patients who received the hypoglossal nerve stimulation implant at a single institution between 2017 and 2021. A combination of descriptive and qualitative data, including age, gender, comorbidities, and postoperative symptoms are analyzed to characterize patient outcomes resulting from this intraoperative technique. The categorical and continuous variables were analyzed using chi-squared tests and independent t-tests, respectively. RESULTS: Patients report overall satisfaction after implantation and titration. A total of 108 patients underwent HGNS implantation between September 2017 and January 2021 using the aforementioned techniques. 1.69 % of patients experienced postoperative submental pain as compared to 18.37 % prior to the change in technique (p < 0.01). CONCLUSION: Avoidance of digastric tendon retraction in the implantation of the stimulating lead is a safe and effective technique that reduces postoperative pain and discomfort. Our institution has demonstrated an alternative technique for hypoglossal stimulator implantation which improves perioperative outcomes. LAY SUMMARY: Upper airway stimulation is an effective treatment for obstructive sleep apnea. During surgery, the digastric tendon is often moved to identify the nerve and improve access. This study shows that avoiding digastric tendon movement safely reduces postoperative pain and discomfort. LEVEL OF EVIDENCE: III.

Central Tendon Tenotomy for Management of Extrinsic Extensor Tightness of the Hand: Surgical Technique and Case Reports.

CASE: We present a 67-year-old woman with long finger extrinsic extensor tightness and a 56-year-old man with limited index finger flexion due to extrinsic extensor tightness secondary to tendon transfers for radial nerve palsy. Both patients underwent prior surgical procedures that led to limited range of motion (ROM). Subsequently, they elected for central tendon tenotomy (CTT), which demonstrated postoperative ROM improvement and satisfactory patient outcomes. CONCLUSION: Surgical management of extrinsic extensor tendon tightness of the hand is generally addressed by performing tenolysis to improve tendon excursion. We present a novel and simple technique of CTT with pertinent anatomy, descriptive cases, and a cadaveric video.

[Long head of the biceps pathologies : diagnosis and treatments]. / Diagnostics et traitements des pathologies du long chef du biceps.

The long head of the biceps (LHB) tendon is a common source of shoulder pain. Often associated with other injuries, the tendon can alone be responsible of the symptoms. Spontaneous rupture has been observed to allow for pain relief. The spectrum of LHB lesions is broad. Repetitive motion, carrying heavy loads, have been associated with diagnosis. Specific tests have been described to diagnose biceps injuries, their implementation can remain difficult in the presence of associated pathologies. The combination of a history and clinical examination with the use of targeted imaging is required to establish the diagnosis. The management of bicipital pathologies is frequently carried out following main surgical procedures. Isolated management of biceps lesions can provide a satisfactory result when a comprehensive procedure cannot be performed.

Le tendon du long chef du biceps (LCB) est une source fréquente de douleurs à l'épaule. Souvent associé à d'autres atteintes, il peut être seul responsable de la symptomatologie et sa rupture peut apporter un soulagement « salvateur ¼. Le spectre des lésions du LCB est large. Les mouvements répétés de lancer, tirer ou le port de charges ont été associés à une atteinte du LCB. De nombreux examens spécifiques ont été développés afin de diagnostiquer ces lésions. Leur réalisation peut rester un défi clinique en cas de pathologies associées. Une anamnèse, un examen clinique ainsi qu'une imagerie ciblée sont requis pour établir le diagnostic. La prise en charge de ces lésions est souvent réalisée durant des procédures chirurgicales principales. Leur prise en charge isolée permet un résultat fonctionnel satisfaisant lorsqu'un geste exhaustif ne peut être réalisé.

Snapping Complication After Partial-Thickness Quadriceps Tendon Autograft Anterior Cruciate Ligament Reconstruction: A Report of 2 Cases.

CASE: A 14-year-old adolescent girl and 18-year-old man underwent right anterior cruciate ligament (ACL) reconstruction using quadriceps tendon (QT) autografts via partial-thickness harvest. While both patients initially recovered well, later they experienced a painful snapping in their knee localized to the lateral QT, just proximal to the patella. Surgical completion of the previous partial-thickness defect with imbrication provided resolution of symptoms at 4 and 9 months postoperatively, respectively. CONCLUSION: We present a snapping QT as a rare complication of partial-thickness QT harvest for ACL reconstruction. Surgical completion of the partial-thickness defect with imbrication resolved the snapping sensation in these two cases.

High Rate of Concomitant Lumbo-Sacral Spine Pathology in the Setting of Hip Abductor Tendon Repair.

BACKGROUND: Hip abductor deficiency is a common cause of lateral hip pain in middle-aged patients. Identifying upstream muscle denervation originating in the lumbo-sacral spine could potentially impact the management of patients who have abductor deficiency. The purpose of this study was to estimate the prevalence of lumbo-sacral pathology (L4 to S1) in patients undergoing hip abductor tendon repair. METHODS: All cases of primary hip abductor repair performed at a tertiary care center between January 2010 and December 2021 were reviewed. Patients were classified into the following groups: A) confirmed L4 to S1 disease based on preoperative or perioperative L4 to S1 interventions (ie, surgery, epidural injections, and/or positive electromyography findings); B) radiographic evidence on lumbar spine magnetic resonance imaging demonstrating nerve compression at L4 to S1; and C) no evidence of L4 to S1 disease. RESULTS: There were 131 cases of primary hip abductor repair that were included. Over 80% of patients were women, who had a mean age of 64 years (range, 20 to 85). There were thirteen patients (9.9%) who underwent concomitant total hip arthroplasty (THA). Of the included patients, 29% (n = 38) were categorized into group A, 12% (n = 16) into group B, and 59% (n = 77) into group C. Patients who had L4 to S1 pathology were older than patients who did not have L4 to S1 pathology (67 versus 61 years, P = .004). Of the patients undergoing concomitant THA and hip abductor repair, 54% demonstrated evidence of lumbo-sacral spine pathology. CONCLUSIONS: Over 40% of patients undergoing isolated hip abductor tendon repair and >50% of patients undergoing concomitant hip abductor tendon repair and THA demonstrated evidence of L4 to S1 disease perioperatively. Patients demonstrating symptomatic hip abductor deficiency should be screened for concomitant lower lumbo-sacral spine pathology.

Postural Stability and Pedobarography After Reconstruction of Peroneus Brevis Tendon Split Lesion.

PURPOSE: Lesions of the peroneal tendons are frequently overseen after ankle sprain. The symptoms consist of stress-dependent pain that extends from the inframalleolar to the proximal part along the course of the peroneal tendons as well as ankle instability and soft-tissue swelling. In case of unsuccessful conservative treatment, surgical therapy is recommended. The aim of the study was to evaluate the clinical and functional outcome after open reconstruction of the peroneus brevis tendon. METHODS: 13 patients were included in this retrospective study. All of them received a single reconstruction of the peroneus brevis tendon in open technique. Postoperative results were evaluated with the AOFAS score, a functional and perdobargraphic analysis as well as measuring postural stability with the Biodex balance system. The participants were matched with a healthy control group according to age, sex and BMI. RESULTS: The results of the AOFAS score showed significantly convincing results in all subscores postoperatively. A bilateral comparison of the postural stability showed that the affected side had become functionally similar to the healthy side. No statistical significant difference was detected concerning both one-legged and two-legged standing with the control group. Pedobarographic results revealed no difference between the affected and contralateral side, as well as between the patients and the healthy control group. CONCLUSION: Open reconstruction of the peroneus brevis tendon leads to significant better postoperative results and can be recommended after unsuccessful conservative treatment as promising option.

Small tuck for superior oblique palsy.

PURPOSE: To investigate the surgical outcomes of small superior oblique (SO) tuck-denoting minimal tendon laxity-in patients with unilateral SO palsy. METHODS: The medical records of consecutive patients treated with ≤6 mm SO tuck from 2000 to 2018 at Kellogg Eye Center, University of Michigan, were reviewed retrospectively. Tendon tucks were performed to a fairly uniform tension in an amount that just eliminated slack in the tendon. Pre- and postoperative motility measurements were compared. Patients were excluded if they had a history of prior strabismus surgery or concurrent vertical rectus or inferior oblique surgery. RESULTS: A total of 27 cases (14 males) met inclusion criteria. The median age at surgery was 47 years (range 3-74 years). The mean SO tuck (total, both arms of tuck) was 4.9 mm (range, 2-6 mm). After surgery, median hypertropia decreased from 9Δ to 1Δ in primary position and from 20Δ to 4Δ in the SO field of action (contralateral downgaze). Lateral incomitance (difference in hypertropia between contralateral and ipsilateral gaze) decreased from 10Δ to 2Δ (P < 0.001 in each case). Six patients had diplopia in upgaze postoperatively that was not symptomatic enough to require reoperation. Six patients had residual hypertropia requiring additional surgery. CONCLUSIONS: Small SO tuck provided disproportionate correction of hypertropia in the SO field of action and nearly eliminated lateral incomitance without producing unacceptable iatrogenic Brown syndrome. Even in the absence of tendon laxity, SO tuck was a good surgical option for SO palsy in our cohort where there was marked lateral incomitance and the greatest deviation was in the SO field of action.

Percutaneous needle tenotomies: indications, procedures, efficacy and safety. A systematic review.

BACKGROUND: Percutaneous needle tenotomies constitute a promising approach that enables direct access to tendons through minimally invasive interventions. They can be performed rapidly without need for large incisions or general anaesthesia. However, the reported procedures are heterogeneous and currently conducted without guidelines. OBJECTIVES: We aimed to determine the indications for percutaneous needle tenotomies described in the current literature. Our secondary aim was to identify the different procedures reported, as well as their efficacy and their safety. METHODS: A systematic review following PRISMA guidelines was conducted to identify original articles that mentioned percutaneous needle tenotomy in humans and reported its application, description, effectiveness or adverse events. Non-percutaneous tendinous surgical procedures and ineligible designs were excluded. The Downs and Black checklist was used to assess the risk of bias. RESULTS: A total of 540 studies were identified from the MEDLINE, Embase, Cochrane Library, and PEDro databases. Fourteen clinical studies met the inclusion criteria and were found to have an acceptable quality (674 individuals, 1664 tenotomies). Our results indicated a wide variety of indications for percutaneous needle tenotomies in children and in adults. We highlighted 24 tendons as eligible targets in the upper and lower limbs. Tenotomies were performed with either 16- or 18-Ga needles, lasted from 1 to 30 min, and were performed using various procedures. Their efficacy was mainly assessed through clinical outcomes highlighting tendon discontinuity on palpation after the procedure. Passive range-of-motion gains after tenotomy were reported for both upper and lower limbs with an estimated 5 % complication rate. CONCLUSION: This is the first review to systematically synthesize all the available evidence on the indications, procedures, efficacy and safety of percutaneous tenotomies exclusively performed with needles. Current evidence suggests that procedures are safe and effective for treating various deformities. PROSPERO REGISTRATION: CRD42022350571.

Clinical Effects of Tibial Posterior Tendon Reconstruction in the Treatment of Young Athletes With Accessory Navicular Bone Syndrome.

OBJECTIVE: To compare the effects of anchor reconstruction of posterior tibial tendon with the traditional Kidner's procedure for accessory navicular bone syndrome. METHODS: A retrospective analysis was conducted on 40 young athletes diagnosed with accessory navicular bone syndrome who were admitted to our hospital from 2018 to 2021. Among them, 20 patients underwent the modified Kidner procedure for the anchor reconstruction of the posterior tibial tendon (Experimental group), while the remaining 20 patients were treated with the traditional Kidner's procedure (Control group). Regular follow-ups were conducted to evaluate the degree of relief of foot symptoms and functional recovery. RESULTS: All patients were followed up for 12 to 24 months (mean duration: 18.6±3.7) after the operation. At the last follow-up, significant differences were observed in the function and symptom relief of the affected foot compared to the preoperative state. The experimental group had a mean operation time of 52.10 ± 3.41 minutes, significantly shorter than the control group's 61.25 ± 2.75 minutes. The mean time to return to normal activity was 12.65 ± 1.23 weeks for the experimental group, compared to 15.25 ± 1.16 weeks for the control group. CONCLUSION: The modified Kidner procedure demonstrates a higher patient satisfaction rate compared to the traditional Kidner procedure. This is attributed to its shorter duration, reduced trauma, and quicker recovery of normal activity.

Superior capsular reconstruction with the long head of the biceps tendon achieves excellent clinical results and low rotator cuff rerupture rates one year after cuff repair surgery.

PURPOSE: To analyze the clinical one-year evolution of healed and rerupture lesions in patients who received a rotator cuff repair plus Superior Capsular Reconstruction (SCR) with the long head of the biceps (LHB). Moreover, to compare this evolution between men and women. METHODS: A pilot study was conducted on patients who underwent a rotator cuff repair plus SCR with LHB between February 2021 and June 2022. All patients completed pre-operative and one-year post-operative evaluations for tendon type of tear and tendon integrity using Magnetic Resonance Imaging (MRI)after one year of the surgery. Besides, functionality was evaluated with the American Shoulder and Elbow Surgeons (ASES) score; the visual analog scale for pain (VAS); and the Constant score. RESULTS: A total of 38 patients completed the one-year final evaluation, they presented an increased functionality score to 83 and 86 in Constant and ASES scales (p < .001), respectively. Besides, 84% of the patients presented a healed cuff, while rerupture occurred in 16% of the patients. There were differences between the healed and rerupture patients in the total Constant score, with a remarkable increase in the strength subscale, almost double for patients with healed cuff (p < .001); in the same way, daily life activity score, and balance subscale increased, while pain score decreased in the healed cuff group (p < .05). There was no difference in functionality between men and women (p > .05). Besides, almost all patients achieved the MCID in both ASES and Constant total scores, irrespectively of the healing group. CONCLUSION: The cuff repair using SCR with the LHB achieved a low percentage of rerupture and a functional improvement after one year of follow-up. Patients who healed the lesion presented more strength and better performance in daily life activities than those with cuff repurture. Thus, SCR + LHB procedure can be considered an efficient technique for rotator cuff repair surgery for both men and women. Although a comparison with a control group is needed to confirm these findings.

Optimizing Muscle-Tendon Lengths in Reverse Total Shoulder Arthroplasty: Evaluation of Surgical and Implant-Design-Related Parameters.

BACKGROUND: Optimizing the function of muscles that cross the glenohumeral articulation in reverse total shoulder arthroplasty (RTSA) is controversial. The current study used a geometric model of the shoulder to systematically examine surgical placement and implant-design parameters to determine which RTSA configuration most closely reproduces native muscle-tendon lengths of the deltoid and rotator cuff. METHODS: A geometric model of the glenohumeral joint was developed and adjusted to represent small, medium, and large shoulders. Muscle-tendon lengths were assessed for the anterior deltoid, middle deltoid, posterior deltoid, and supraspinatus from 0 to 90° of scaption; for the subscapularis from 0° to 60° of internal rotation (IR) and 0° to 60° of scaption; for the infraspinatus from 0° to 60° of external rotation (ER) and 0° to 60° of scaption; and for the teres minor from 0° to 60° of ER at 90° of scaption. RTSA designs were virtually implanted using the following parameters: (1) surgical placement with a centered or inferior glenosphere position and a humeral offset of 0, 5, or 10 mm relative to the anatomic neck plane, (2) implant design involving a glenosphere size of 30, 36, or 42 mm, glenosphere lateralization of 0, 5, or 10 mm, and humeral neck-shaft angle of 135°, 145°, or 155°. Thus, 486 RTSA-shoulder size combinations were analyzed. Linear regression assessed the strength of association between parameters and the change in each muscle-tendon length from the native length. RESULTS: The configuration that most closely restored anatomic muscle-tendon lengths in a small shoulder was a 30-mm glenosphere with a centered position, 5 mm of glenoid lateralization, 0 mm of humeral offset, and a 135° neck-shaft angle. For a medium shoulder, the corresponding combination was 36 mm, centered, 5 mm, 0 mm, and 135°. For a large shoulder, it was 30 mm, centered, 10 mm, 0 mm, and 135°. The most important implant-design parameter associated with restoration of native muscle-tendon lengths was the neck-shaft angle, with a 135° neck-shaft angle being favored (ß = 0.568 to 0.657, p < 0.001). The most important surgical parameter associated with restoration of native muscle-tendon lengths was humeral offset, with a humeral socket placed at the anatomic neck plane being favored (ß = 0.441 to 0.535, p < 0.001). CONCLUSIONS: A combination of a smaller, lateralized glenosphere, a humeral socket placed at the anatomic neck plane, and an anatomic 135° neck-shaft angle best restored native deltoid and rotator cuff muscle-tendon lengths in RTSA. CLINICAL RELEVANCE: This study of surgical and implant factors in RTSA highlighted optimal configurations for restoration of native muscle-tendon lengths of the deltoid and rotator cuff, which has direct implications for surgical technique and implant selection. Additionally, it demonstrated the most influential surgical and implant factors with respect to muscle-tendon lengths, which can be used to aid intraoperative decision-making.

Subscapularis Management in Anatomic Total Shoulder Arthroplasty A Review.

Surgical management of the subscapularis tendon is critical to a successful outcome following anatomic total shoulder arthroplasty. However, the optimal surgical technique for adequate exposure of the glenohumeral joint while mini-mizing complications resulting from subscapularis tendon dysfunction continues to be controversial. Common surgical techniques for the management of the subscapularis tendon include tenotomy, peeling, sparing, and lesser tuberosity oste-otomy. Despite a number of published studies comparing these techniques, no consensus has been reached regarding optimal management. This article reviews the extensive literature on the biomechanical, radiologic, and clinical outcomes of each technique, including recently published comparison studies.

Biomechanical strength of triceps tendon repairs: systematic review and meta-regression analysis of human cadaveric studies.

PURPOSE: It is unclear which triceps tendon repair constructs and techniques produce the strongest biomechanical performance while minimizing the risk of gap formation and repair failure. We aimed to determine associations of construct and technique variables with the biomechanical strength of triceps tendon repairs. PubMed, Embase, Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov were systematically searched for peer-reviewed studies on biomechanical strength of triceps tendon repairs in human cadavers. 6 articles met the search criteria. Meta-regression was performed on the pooled dataset (123 specimens). Outcomes of interest included gap formation, failure mode, and ultimate failure load. Covariates were fixation type; number of implants; and number of sutures. Stratification by covariates was performed. We found no association between fixation type and ultimate failure load; however, suture anchor fixation was associated with less gap formation compared with transosseous direct repair (ß = - 1.1; 95% confidence interval [CI]:- 2.2, - 0.04). A greater number of implants was associated with smaller gap formation (ß = - 0.77; 95% CI: - 1.3, - 0.28) while a greater number of sutures was associated with higher ultimate failure load ( ß= 3; 95% CI: 21, 125). In human cadaveric models, the number of sutures used in triceps tendon repairs may be more important than the fixation type or number of implants for overall strength. If using a transosseous direct repair approach to repair triceps tendon tears, surgeons may choose to use more sutures in their repair in order to balance the risk of larger gap formation when compared to indirect repair techniques. LEVEL OF EVIDENCE: Level III.

Retrospective analysis of the subscapularis-sparing approach for reverse total shoulder arthroplasty.

PURPOSE: The influence of the subscapularis tendon on reverse total shoulder arthroplasty (RTSA) has been discussed controversially. The aim of the study was to investigate the subscapularis-sparing approach for RTSA and the effect of the intact subscapularis tendon. METHODS: This retrospective comparative study included 93 patients. Among these, 55 underwent the deltopectoral subscapularis-sparing approach, and in 38 cases, the standard deltopectoral approach with subscapularis tenotomy was applied. At the final follow-up, representative shoulder scores were measured, radiographs were taken in two planes, and shoulder sonography was performed. RESULTS: The subscapularis-sparing group showed a significantly higher Constant score (71.8 vs. 65.9 points) and adapted Constant score if the subscapularis tendon was shown to be intact in the postoperative sonography (85.2% vs. 78.6%) (p = 0.005; p = 0.041). Furthermore, these patients had improved abduction (128.2 vs. 116.8, p = 0.009) and external rotation (34.6 vs. 27.1, p = 0.047). However, no significant differences were found for the degree of internal rotation and internal rotation strength. No dislocation or infection was observed. The degree of scapular notching was not significantly different between the two groups (p = 0.082). However, independently from the integrity of the subscapularis the subscapularis-sparing approach showed no difference in clinical and radiographic outcome (Constant score scapularis-sparing 70.0 points vs. tenotomy 66.8 points; p = 0.27). CONCLUSION: The subscapularis-sparing approach RTSA showed improved clinical outcome, abduction, and external rotation, if the subscapularis was shown to be intact at time of follow-up. Both groups showed no difference in internal rotation.

Advancing Novel Strategies against Post-surgical Tendon Adhesion Bands, Exploring New Frontiers.

Current interest in adhesion formation stems from its global impact on the function and quality of life, spanning a spectrum of subtle impairments to significant disabilities, based on the affected area and the extent of adhesion. Yet therapeutic agents are restricted to prophylactic anti-inflammatories, revision surgeries, and biological and physical techniques, none of which grant a decent outcome. Recent advancements in tissue- engineered biomaterials, drug delivery systems, and fabricating technologies such as nanoparticles, hydrogels, and weaving or braiding demonstrate potential for improved outcomes. However, none of the mentioned methods have reliable outcomes, thus this study aims to elucidate the mechanisms involved in the pathophysiology of tendon adhesion and post-surgical adhesion band formation (PSAB), with a closer look at inflammatory pathways stimulating the process. This article consolidates information on diverse therapeutic and prophylactic methods and cutting-edge technologies, aiming to provide a comprehensive update on this topic, and providing researchers an avenue for new and innovative ideas for further investigations.

Biomechanical testing of ex vivo porcine tendons following high intensity focused ultrasound thermal ablation.

INTRODUCTION: Magnetic resonance-guided focused ultrasound (MRgFUS) has been demonstrated to be able to thermally ablate tendons with the aim to non-invasively disrupt tendon contractures in the clinical setting. However, the biomechanical changes of tendons permitting this disrupting is poorly understood. We aim to obtain a dose-dependent biomechanical response of tendons following magnetic resonance-guided focused ultrasound (MRgFUS) thermal ablation. METHODS: Ex vivo porcine tendons (n = 72) were embedded in an agar phantom and randomly assigned to 12 groups based on MRgFUS treatment. The treatment time was 10, 20, or 30s, and the applied acoustic power was 25, 50, 75, or 100W. Following each MRgFUS treatment, tendons underwent biomechanical tensile testing on an Instron machine, which calculated stress-strain curves during tendon elongation. Rupture rate, maximum treatment temperature, Young's modulus and ultimate strength were analyzed for each treatment energy. RESULTS: The study revealed a dose-dependent response, with tendons rupturing in over 50% of cases when energy delivery exceeded 1000J and 100% disruption at energy levels beyond 2000J. The achieved temperatures during MRgFUS were directly proportional to energy delivery. The highest recorded temperature was 56.8°C ± 9.34 (3000J), while the lowest recorded temperate was 18.6°C ± 0.6 (control). The Young's modulus was highest in the control group (47.3 MPa ± 6.5) and lowest in the 3000J group (13.2 MPa ± 5.9). There was no statistically significant difference in ultimate strength between treatment groups. CONCLUSION: This study establishes crucial thresholds for reliable and repeatable disruption of tendons, laying the groundwork for future in vivo optimization. The findings prompt further exploration of MRgFUS as a non-invasive modality for tendon disruption, offering hope for improved outcomes in patients with musculotendinous contractures.