Distal Anchor Research Articles

Arthroscopic Bone Block Cerclage Suture Fixation of Fresh Distal Tibial Allograft for Anterior Glenoid Reconstruction

Glenoid bone loss in patients with recurrent anterior shoulder instability poses a unique challenge to treating surgeons. Various bone block procedures have been used to reconstruct the glenoid, including autologous coracoid transfer, iliac crest autograft, distal clavicle autograft, and distal tibia allograft. Distal tibia allograft has been increasingly used because of its advantages over autologous graft sources. Having started out as an open procedure, glenoid reconstruction with distal tibia allograft has now found its way to evolving into an arthroscopic procedure. Various techniques have been devised for arthroscopic distal tibia allograft fixation, including screw, suture anchor, and suture button. This technical note describes an arthroscopic distal tibia allograft fixation technique, using a transglenoid parallel drill guide and 2 cerclage tape sutures that are fastened using a tensioner. This technique provides strong graft fixation while avoiding the potential complications and technical challenges of metal screw fixation.

Growth-preserving instrumentation for early onset scoliosis

Early onset scoliosis is defined as aspinal deformity originating in the first 10years of life. Growth-preserving spinal instrumentation has therefore been designed to preserve growth of spine and chest wall and lungs to avoid serious pulmonary complications after early spine fusion. Indications, surgical technique and results of the vertical expandable prosthetic titanium rib (VEPTR) technique, traditional growing rods (TGR), and magnetically controlled growing rods (MCGR) will be described. Indications for VEPTR are so-called mixed congenital deformities (type3) associated with vertebral malformations in association with chest wall deformities, especially fused ribs. There are also indications for neuromuscular or syndromic early onset scoliosis with bilateral rib-to-ilium constructs. However, most of those deformities are currently treated with either GR or MCGR in most centers. GR and MCGR are currently the treatment of choice for the majority of early onset scoliosis. There is no indication for growth-preserving strategies if the patients are mature or there is only little growth remaining. In these cases, final fusion should be performed. While the VEPTR technique involves an extensive approach with muscular dissections to the thoracic cage including rib osteotomies and thoracotomies, treatment with TGR or MCGR is minimally invasive, only exposing proximal and distal anchor points, leaving most of the spine including the apex undisturbed. Early mobilization is usually possible after 24-48 h. Braces may have to be prescribed for patients with osteopenia, noncompliance, or arisk to fall. Since 2005, more than 200patients were treated with the VEPTR technique, more than 200 patients with the MCGR technique, and about 30patients with the TGR technique in our department. Complication rates are high with all techniques including the law of diminishing returns, autofusion, bone anchor-related complications like loosening or migration of implants, failure to distract and proximal junctional kyphosis. In our own series of 13patients below age 3years, VEPTR proved to be effective for mixed deformities. In other studies, we were able to show that physiological growth with MCGR can be maintained for 2-3years but spinal growth declines after that period with acceptable complications. Complication rates in most studies are lower with MCGR compared to TGR and VEPTR. Therefore, it is currently the treatment of choice for most early onset scoliosis patients.

Rib-to-spine and rib-to-pelvis magnetically controlled growing rods: does the law of diminishing returns still apply?

The Law Of Diminishing Returns (LODR) has been demonstrated for traditional growing rods, but there is conflicting data regarding the lengthening behavior of Magnetically Controlled Growing Rods (MCGR). This study examines a cohort of patients with early-onset scoliosis (EOS) with rib-to-spine or rib-to-pelvis-based MCGR implants to determine if they demonstrate the LODR, and if there are differences in lengthening behaviors between the groups. A prospectively collected multicenter EOS registry was queried for patients with MCGR with a minimum 2-year follow-up. Patients with rib-based proximal anchors and either spine- or pelvis-based distal anchors were included. Patients with non-MCGR, unilateral constructs, < 3 lengthenings, or missing > 25% datapoints were excluded. Patients were further divided into Primary-MCGR (pMCGR) and Secondary-MCGR (sMCGR). 43 rib-to-spine and 31 rib-to-pelvis MCGR patients were included. There was no difference in pre-implantation, post-implantation and pre-definitive procedure T1-T12 height, T1-S1 height, and major Cobb angles between the groups (p > 0.05). Sub-analysis was performed on 41 pMCGR and 19 sMCGR rib-to-spine patients, and 31 pMCGR and 17 sMCGR rib-to-pelvis patients. There is a decrease in rod lengthenings achieved at subsequent lengthenings for each group: rib-to-spine pMCGR (rho = 0.979, p < 0.001), rib-to-spine sMCGR (rho = 0.855, p = 0.002), rib-to-pelvis pMCGR (rho = 0.568, p = 0.027), and rib-to-pelvis sMCGR (rho = 0.817, p = 0.007). Rib-to-spine pMCGR had diminished lengthening over time for idiopathic, neuromuscular, and syndromic patients (p < 0.05), with no differences between the groups (p > 0.05). Rib-to-pelvis pMCGR neuromuscular patients had decreased lengthening over time (p = 0.01), but syndromic patients had preserved lengthening over time (p = 0.65). Rib-to-spine and rib-to-pelvis pMCGR and sMCGR demonstrate diminished ability to lengthen over subsequent lengthenings.

Shape memory polymer technology in peripheral vascular embolization.

Porous, radiolucent, shape memory polymer is a new technology available in discrete peripheral vascular embolization devices. Shape memory polymers can exist in two stable shapes; crimped for catheter delivery and expanded for vessel embolization. The expanded shape memory polymer in these new devices is hemostatic, and the porous polymeric scaffold has been shown to support tissue ingrowth and eventually bioabsorbs in preclinical animal studies. This report describes clinical experience with this novel material in vascular plug devices. a prospective, single-arm, safety study at a single center in New Zealand with longer term follow-up via retrospective imaging review. The study device was a pushable shape memory polymer vascular plug with a distal nitinol anchor coil and a proximal radiopaque marker. Ten male patients were each implanted with a single shape memory polymer vascular plug. Three inferior mesenteric arteries and an accessory renal artery were embolized during endovascular aneurysm repair. An internal iliac artery was treated prior to the open surgical repair of aorto-iliac aneurysms. An internal iliac artery and a subclavian artery were embolized to treat/prophylactically address potential endoleaks. A profunda branch was embolized prior to tumor resection, and two testicular veins were embolized to treat varicoceles. Acute technical success of target vessel embolization was achieved in all implantation cases. Patients were followed for 30days as part of the study, and no serious adverse events with a relationship to the study device occurred. No recurrent clinical symptoms attributable to treated vessel embolization or recanalization were documented. There was no evidence of recanalization on retrospective review of follow-up imaging through a mean of 22.2months (range, <1-44months) post-procedure. Shape memory polymer vascular embolization devices were safe and effective over the follow-up period of this small safety study. Further experience and longer term follow-up will assess further applicability.

Motion Planning for a Cable-Driven Lower Limb Rehabilitation Robot with Movable Distal Anchor Points

This article introduces a cable-driven lower limb rehabilitation robot with movable distal anchor points (M-CDLR). The traditional cable-driven parallel robots (CDPRs) control the moving platform by changing the length of cables, M-CDLR can also adjust the position of the distal anchor point when the moving platform moves. The M-CDLR this article proposed has gait and single-leg training modes, which correspond to the plane and space motion of the moving platform, respectively. After introducing the system structure configuration, the generalized kinematics and dynamics of M-CDLR are established. The fully constrained CDPRs can provide more stable rehabilitation training than the under-constrained one but requires more cables. Therefore, a motion planning method for the movable distal anchor point of M-CDLR is proposed to realize the theoretically fully constrained with fewer cables. Then the expected trajectory of the moving platform is obtained from the motion capture experiment, and the motion planning of M-CDLR under two training modes is simulated. The simulation results verify the effectiveness of the proposed motion planning method. This study serves as a basic theoretical study of the structure optimization and control strategy of M-CDLR.

C7 distal fixation anchor and its influence on sagittal profile in posterior cervical fusion; a retrospective analysis of 44 cases

Study designRetrospective. PurposeIn multilevel posterior cervical fusion, whether to stop distal fixation at C7 or T1, remains a matter of debate. We aimed to assess clinical feasibility of C7 as distal fixation point and sought to compare complication rates and radiological outcome between lateral mass screws and pedicle screws at C7. Overview of literatureCurrent literature remains inconclusive regarding need for thoracic extension of instrumentation in multilevel posterior cervical fusion. MethodsWe did a retrospective review of 44 consecutive patients who underwent posterior instrumented cervical decompression and fusion for degenerative cervical myelopathy with C7 as distal fixation point, and a minimum follow-up period of two years. We had two groups of patients based on C7 instrumentation. Group 1Lateral mass screw fixation. Group 2Pedicle screw fixation. Primary outcomePost-operative clinico-radiological evaluation of whole study population Secondary outcome: Comparison of complication rates and radiological outcome between groups 1 and 2. ResultsMean age was 58.06 ± 14.4 years with average follow-up duration of 35.4 ± 4.5 months. There were 18 patients in Group 1 and 26 patients in Group 2. Mean pre-operative mJOA score was 10.51 and post-operative mJOA score was 15.74 with mean recovery rate (RR) 69.82%, of which 30 patients (70.23%) had good recovery and 14 patients (29.77%) had fair recovery at final follow up. The two groups didn't show any significant difference in complication rates and outcome. ConclusionC7 as distal fixation anchor is safe and effective in maintaining cervical sagittal balance following multilevel posterior cervical fusion. C7 lateral mass screws are found to be equally efficacious as pedicle screws in preventing worsening of sagittal profile.

Influence of configuration and anchor in ligamentous augmentation to prevent proximal junctional kyphosis: A finite element study.

Ligament augmentation has been applied during spinal surgery to prevent proximal junctional kyphosis (PJK), but the configuration and distal anchor strategies are diverse and inconsistent. The biomechanics of different ligament augmentation strategies are, therefore, unclear. We aimed to create a finite element model of the spine for segments T6-S1. Model Intact was the native form, and Model IF was instrumented with a pedicle screw from segments T10 to S1. The remaining models were based on Model IF, with ligament augmentation configurations as common (CM), chained (CH), common and chained (CHM); and distal anchors to the spinous process (SP), crosslink (CL), and pedicle screw (PS), creating SP-CH, PS-CHM, PS-CH, PS-CM, CL-CHM, CL-CH, and CL-CM models. The range of motion (ROM) and maximum stress on the intervertebral disc (IVD), PS, and interspinous and supraspinous ligaments (ISL/SSL) was measured. In the PS-CH model, the ROM for segments T9-T10 was 73% (of Model Intact). In the CL-CHM, CL-CH, CL-CM, PS-CM, and PS-CHM models, the ROM was 8%, 17%, 7%, 13%, and 30%, respectively. The PS-CH method had the highest maximum stress on IVD and ISL/SSL, at 80% and 72%, respectively. The crosslink was more preferable as the distal anchor. In the uppermost instrumented vertebrae (UIV) + 1/UIV segment, the CM was the most effective configuration. The PS-CH model had the highest flexion load on the UIV + 1/UIV segment and the CL-CM model provided the greatest reduction. The CL-CM model should be verified in a clinical trial. The influence of configuration and anchor in ligament augmentation is important for the choice of surgical strategy and improvement of technique.

Error Compensation in Position and Orientation of Mobile Platform of Cable-Driven Robots via Tensile Forces Measurement

The paper deals with a problem of position and orientation errors of mobile platform of large-sized parallel cabledriven robots. The advantages of parallel cable-driven robots are simplicity of structure and scalability. At the same time, parallel cable-driven robots are difficult to design due to the specific problems such as collision of cables, geometric and structural nonlinearity in the mathematical models of the main elements of the robot. In this paper, we consider the problem of eliminating the uncertainty associated with deformations of the elements of the robot structure. Such a configuration of the cable system is selected, in which the proximal anchor points of some cables can be considered without errors relatively to given positions. The cable system of a large-sized robot is mounted on the towers. The errors in the proximal anchor points relatively to given positions become significant due to the significant deformations of upper sections of the towers. The deformations of the towers in lower sections can be considered insignificant, and the proximal anchor points have to be located no higher than the middle of the tower to be considered corresponding to a given position. The aim is to compensate the position and orientation errors of the mobile platform of large-sized parallel cable-driven robot due to deformations of the cables and towers. The task suppose uncertainty about the coordinates of the proximal anchor points of the upper cables. Cable deformations are determined from Hooke’s law using tensile forces measurement in cables. The problem of compensations is solved in two stages. At the first stage, the approximate bias of the center of mass of the mobile platform along the vertical coordinate is found. It is defined as the height of the truncated pyramid, the edges of which are formed by stretched lower cables. At the second stage, rotation angles of the mobile platform are determined. Using the rotation matrix, biases in the heights of each distal anchor points are found in the tool coordinate system. In the studied cases PID regulation is used, however, more advanced techniques of automatic regulation, for example, optimal control, can provide better results. The tasks are applied to the model of large-sized symmetric parallel eight-cable-driven robot.

Minimally Invasive Mid-Substance Achilles Tendon Repair Using the Percutaneous Achilles Repair System (PARS).

Minimally Invasive Mid-Substance Achilles Tendon Repair Using the Percutaneous Achilles Repair System (PARS).

Pelvic fixation is not always necessary in children with cerebral palsy scoliosis treated with growth-friendly instrumentation.

A previous study showed that patients with neuromuscular scoliosis who underwent fusion to L5 had excellent coronal curve correction and improvement in pelvic obliquity (PO) when preoperative L5 tilt was < 15°. Our purpose was to identify indications to exclude the pelvis in children with cerebral palsy (CP) scoliosis treated with growing-friendly instrumentation. In a retrospective cohort study, children with CP scoliosis treated with TGR, MCGR, or VEPTR with minimum 2-year follow-up were identified from a multicenter database. 27 patients with distal spine anchors (DSA) and 71 patients with distal pelvic anchors (DPA) placed at the index surgery were analyzed. The DSA group had a lower pre-index PO (9° vs 16°, P = 0.0001). Most recent radiographic data were similar except the DSA patients had a smaller major curve (47° vs 58°, P = 0.038). 6 (22%) DSA patients underwent extension of the instrumentation to the pelvis (DSA-EXT), most commonly at final fusion (5 patients). DSA-EXT patients had a higher pre-index L5 tilt than patients who did not require extension (DSA-NO EXT) (19° vs 10°, P = 0.009). Sub-analysis showed a lower major curve at most recent follow-up in the DSA-EXT group compared to the DPA group (33° vs 58°, P = 0.021). The DSA-EXT group had a higher number of complications per patient compared to the DSA-NO EXT group (2.3 vs 1.1, P = 0.029). Pre-index L5 tilt ≤ 10° and PO < 10° may be indications to exclude the pelvis in children with CP scoliosis treated with growth-friendly instrumentation. DSA may provide better long-term control of the major curve than DPA.

Connective Tissue Disease Patients Maintain Greater Distraction During Growth Friendly Surgery

Study Design: Multicenter retrospective study. Background: Recent studies have demonstrated diminishing returns in patients with early onset scoliosis (EOS) undergoing repeated lengthening of growing rods. Little is known about whether this same phenomenon occurs in patients with lax connective tissue disease (CTD). The primary purpose of this study is to investigate whether EOS patients with connective tissue laxity disorders have diminishing returns during growth friendly surgery. Methods: CTD EOS patients below 10 years old, underwent growth friendly spine surgery with distal anchors and at least 1 proximal spine anchor, and had minimum follow-up of 5 years were included in this study. Coronal T1-S1 height at preindex surgery, postindex, and every available lengthening was assessed. Mean coronal height change during early set distractions and late set distractions were calculated for the cohort. To account for varying distraction intervals, we normalized the distractions by the time interval. The outcome parameter was T1-S1 height gain, mm/year. Results: Twenty-one CTD patients were included in this study. Total coronal height (T1-S1) was 26.7MHCcm before index, 32.2 cm at D1-D3, 34.7 cm at D4-D6, and 36.7 cm at D7-L10. There were no significant differences in coronal height gains between early and late distractions (P=0.70). Moreover, when normalized for time, there was no significant difference in net gain per year at different lengthening time points for the CTD group, P=0.59. Conclusion: There is no evidence of diminishing returns in coronal T1-S1 height gain in patients with EOS in the setting of CTD. Level of Evidence: Level III.

Maximizing mechanical advantage: surgical technique increases stiffness in spinal instrumentation.

While there has been a great improvement in the treatment of adolescent idiopathic scoliosis, sagittal deformity correction has remained challenging. Increased rod stiffness has been shown to reduce thoracic flattening. We propose that the surgical technique can increase rod stiffness. A mechanical study was created to quantify the effect this has on construct stiffness. The sagittal bending stiffness of a constrained over contoured rod was measured using four different commonly used instrumentation systems. Pedicle screws were secured into custom printed blocks. One block was completely immobilized, while the other block was subject to four levels of constraint. This includes no constraint, mild constraint, moderate constraint, and maximal constraint with both blocks immobilized. The rod apex was loaded until 1cm of displacement occurred. The stiffness was then calculated and compared between groups. All four rod types showed increased bending stiffness as the construct became more constrained. The moderately constrained and the maximally constrained groups had a significantly higher stiffness compared to the unconstrained groups in all rod types (p < 0.05). The 6.0mm titanium circular rods showed the highest increase in stiffness between maximal and no constraint, which became 3.02 × stiffer. Rod stiffness is not only determined by size, shape, and metal alloy, but also by surgical technique. Constraining the spinal instrumentation by first locking the rod to the proximal and distal anchors significantly increases the sagittal bending stiffness. In a mechanical model this technique increases rod bending stiffness regardless of the material or shape.

Procedural planning of CS-based indirect mitral annuloplasty using CT-angiography.

Coronary sinus (CS) based mitral annuloplasty using the Carillon device could be limited by compromise of the left circumflex artery (Cx). Computed tomography (CT) might be a feasible tool for preprocedural planning of indirect mitral valve annuloplasty. In a retrospective analysis, 25 patients underwent Carillon device implantation and received CT-angiography (CTA) analysis prior to CS based percutaneous mitral valve repair. We used a retrospective approach with preprocedural CTA and intraprocedural coronary sinus angiography (CSA) measurements to determine the CS to Cx distance at the occlusion or compression point or in the distal landing zone in absence of Cx compromise. According to left coronary artery angiography, we identified 7 patients with Cx occlusion, 7 with Cx compression and 11 without Cx compromise. No difference in minimal CS to Cx distance between the three groups could be obtained. Also, neither distal CS diameter nor distal Carillon anchor size were related to Cx impingement. However, ROC analysis identified a CS to Cx distance of <8.6 mm specifically in the distal device landing zone to predict Cx compromise. Furthermore, CTA was accurate in assessing device length in comparison to CSA, but failed predicting Carillon device anchor size. CTA derived CS to Cx distance in the device landing zone might be helpful to predict Cx occlusion during Carillon device implantation. Furthermore, CTA predicted CS length but not anchor size correctly. Therefore, CT-angiographic procedural planning might help improving the results of percutaneous CS-based mitral valve repair.

Numerical and Experimental Assessment of a Novel Anchored for Intramedullary Telescopic Nails Used in Osteogenesis Imperfecta Fractures

Osteogenesis Imperfecta (IO) is a bone disease mainly characterized by the low bone density that produces common fractures in children around 0–7 years. The use of metal implants is a typical treatment of this disease. The intramedullary telescopic nail (ITN) was inspired by the progressive growth in the long bones such as the femur or humerus during children’s aging. This work shows an experimental assessment of the ITN’s, focusing on their fixation; the proposed improvements in the design of the intramedullary nail studied include the separation of the element into two parts for telescopic enlargement, minimal invasive fixation through the distal anchorage, and the double auto-drilled end for fixation on the distal and proximal section of the bone. The samples were manufactured in 316 L steel and mounted on specialized jaws to replicate the implants’ boundary conditions. The experimental test was repeated three times to report the intramedullary telescopic nail’s behavior at three lengths. The results show that the device supports only 79.06 N when not at extension length. However, if the device is extended 150% it will support 46.87 N which suggests that intramedullary telescopic nails can only increase by 25% of their original length before they fail.

Different distal fixation anchors in lumbosacral spinal deformities associated with sacral agenesis: which one is better?

Sacral agenesis (SA) is a rare congenital malformation of the spine. There has been a paucity of clinical research to investigate the surgical outcome of spinopelvic fixation in these patients. In this study, the authors aimed to evaluate the outcome of different distal fixation anchors in lumbosacral spinal deformities associated with SA and to determine the optimal distal fixation anchor. Patients with diagnoses of SA and lumbosacral scoliosis undergoing spinopelvic fixation with S1 screws, iliac screws, or S2-alar-iliac (S2AI) screws were analyzed. The main curve, coronal balance distance, and pelvic obliquity were compared at baseline, postoperatively, and during follow-up in three groups. The complications were also recorded. A total of 24 patients were included: 8 patients were stratified into group 1 (S1 screws), 9 into group 2 (iliac screws), and 7 into group 3 (S2AI screws). The main curves were well corrected postoperatively (p < 0.05) in all groups. Coronal balance showed a tendency of deterioration during follow-up in patients with S1 screws (from 18.8 mm to 27.0 mm). Regarding pelvic obliquity, patients with both iliac and S2AI screws showed significant correction (from 3.7° to 2.3° and from 3.3° to 1.6°). Implant-related complications were rod breakage in 3 patients and infection in 1 patient in group 2, and no implant-related complications were observed in group 3. There were 3 cases of unilateral S1 pedicle screw misplacement in group 1. Spinopelvic fixation is a safe and effective procedure that can achieve coronal correction in lumbosacral scoliosis associated with SA. Compared with S1 and iliac screws, S2AI screws as distal fixation anchors can achieve a more satisfactory correction with fewer implant-related complications.

Towards a validated patient-specific computational modeling framework to identify failure regions in traditional growing rods in patients with early onset scoliosis

BackgroundWhile growing rods are an important contribution to early-onset scoliosis treatment, rod fractures are a common complication that require reoperations. A recent retrieval analysis study performed on failed traditional growing rods revealed that there are commonalities among patient characteristics based on the location of rod fracture. However, it remains unknown if these locations correspond to high stress regions in the implanted construct. MethodsA patient-specific finite element scoliotic model was developed to match the pre-operative (pre-op) scoliotic curve of a patient as described in previously published articles, and by using the patient registry information along with biplanar radiographs. A dual stainless-steel traditional growing rod construct was implanted into this scoliotic model and the surgical procedure was simulated to match the post-operative (post-op) scoliotic curve parameters. Muscle stabilization and gravity was simulated through follower load application. Rod distraction magnitudes were chosen based on pre-op to post-op cobb angle correction, and flexion bending load was simulated to identify the high stress regions on the rods. ResultsThe patient-specific finite element model identified two high stress regions on the posterior surface of the rods, one at mid construct and the other adjacent to the distal anchors. This correlated well with the data obtained from the retrieval analysis performed by researchers at U.S. Food and Drug Administration (FDA) which showed the posterior surface of the rod as the fracture initiation site, and the three locations of failure as mid-construct, adjacent to distal anchors, and adjacent to tandem connector. ConclusionsThe result of this study confirms that the high stress regions on the growing rods, as identified by the FEA, match the fracture prone sites identified in the retrieval analysis performed at the FDA. This proof-of-concept patient-specific approach can be used to predict sites prone to fracture in growing rods.

Calcaneal Stress Reaction with Distal Anchor Fixation for Mid-Substance Achilles Ruptures

Category:Sports; OtherIntroduction/Purpose:Minimally invasive Achilles rupture treatment has been purported to lead to superior outcomes relative to open treatment. Various forms of minimally invasive treatment exist. One newer technique involves the use of suture proximally that anchors into interference screws distally in the calcaneus. This treatment paradigm potentially addresses some deficiencies of other techniques. However, the authors have noted calcaneal stress reactions in some patients with this technique and here we report our experience.Methods:We conducted a retrospective chart review of patients that had minimally invasive Achilles tendon repair performed by the senior author. Patient demographics, medical history, social history, surgical details, and additional surgeries were recorded. The presence of a calcaneal stress reaction, as evidenced by pain near the calcaneal anchor insertion and confirmed via MRI was reviewed. A comparison was made between those patients that did and did not have a stress reaction.Results:Of the 30 included patients, the average age was 36.93 (+-13.17) and 63.3% were male. The mean BMI in this cohort was 28.76 (+-7.62). 66.7% injured themselves while played a sport. 4 patients (13.3%) had a stress reaction from suture anchors. When comparing those who had a stress reaction to those who did not, independent samples t-test revealed that age (p=0.168) and BMI (p=0.568) were not significantly different between the groups. Chi square noted that gender (p=0.87), ASA score (p=0.449), and mechanism of injury (p=0.486) were not significantly associated. All of the patients that sustained a stress reaction were very fit and active.Conclusion:This case series notes the presence of calcaneal stress reaction in 4/30 patients treated for an Achilles tendon rupture with distal anchor fixation. This stress reaction has not been previously reported. It should be noted that the stress reaction was self-limited in all patients. It typically became symptomatic around the 3-4 month after surgery mark and resolved by 5-6 months.

Functional Outcomes and MRI Results Following Knotless Repair of Acute Achilles Tendon Ruptures

Category:Ankle; SportsIntroduction/Purpose:The surgical techniques for primary repair of acute Achilles tendon ruptures have evolved from large open incisions to mini-open and percutaneous techniques. Studies have demonstrated that lesser invasive surgical techniques may reduce the risk of post-operative wound complications. Knotless surgical repair of acute Achilles tendon ruptures can be performed through a mini-incision, but still permits a robust re-approximation of the tendon stumps and decreases suture burden through distal anchor fixation in the calcaneus. However, stress shielding and subsequent tendinosis of the distal tendon stump is a theoretical concern with this surgical technique. We hypothesize that our surgical technique allows for a durable repair through a minimally invasive approach, permitting a safe and accelerated rehabilitation protocol, excellent functional outcomes, and absence of distal stump tendinosis.Methods:A multicenter retrospective chart review was performed to identify all patients that underwent primary Achilles tendon repair using a knotless surgical technique with a minimum of one-year follow-up from three orthopedic foot and ankle surgeons’ practices. Exclusion criteria included: age <18, chronic Achilles tendon ruptures (>4 weeks), insertional Achilles tendon ruptures, revision Achilles surgery, peripheral neuropathy, and systemic inflammatory disease. All patients were contacted by phone and asked to return to the office for an MRI, clinical examination, and completion of functional outcome questionnaires. The primary outcome measure was the validated Achilles Tendon Total Rupture Score (ATRS). Secondary outcomes included the Visual Analog Score (VAS), postoperative complications, ankle range of motion, calf circumference, and single-heel rise. MRI was used to assess tendon continuity and healing, tendinosis, muscle atrophy, and bone marrow edema/stress fracture associated with anchor fixation in the calcaneus. MRI interpretation was performed by a single, blinded musculoskeletal radiologist.Results:Forty-three patients were identified with acute Achilles tendon ruptures. There were 36 patients (36/43, 84%) who underwent knotless Achilles tendon repair and agreed to participate in the study. The average time to clinical follow-up was 23.5 months (SD±16.3). The mean postoperative ATRS was 84.6 (SD±19.7). There was no significant difference in calf circumference (p=0.22), dorsiflexion (p=0.07), and plantarflexion (p=0.11) between the unaffected and surgical extremity at latest follow-up. One patient (1/36, 2.8%) experienced a re-rupture. There were no wound complications or neuritis. MRI was obtained in 26 patients (26/36, 72.2%) at an average of 17.5 months (SD±10.1). There were no MRI findings of distal stump tendinosis or calcaneal stress fractures. Thirty-two patients (32/36, 88.8%) returned to the same athletic activities one-year after surgery.Conclusion:There is paucity in the literature on functional outcomes following knotless Achilles tendon repair. In this multicenter study, we found that validated functional outcome scores and return to activity were similar to historical controls, with a low rate of surgical complications. MRI obtained in twenty-six patients (72.2%) at 17.5 months demonstrated an intact tendon without distal tendon stump stress shielding or calcaneal stress fracture. The knotless Achilles tendon repair is a unique surgical technique, minimizing suture burden and postoperative complications, while offering excellent functional outcomes and return to activity at two-year follow-up. The excellent clinical outcomes are corroborated by MRI.

Optimization of the knot configuration for early accelerated rehabilitation after Achilles tendon rupture

Background Panda Rope Bridge Technique (PRBT) was an new minimally invasive technique consisted of two bridge anchors (proximal anchors at calcaneus and distal anchors at myotendinous junction) and strong ropes (threads of the suture anchors) stretched between them, which was suitable for early accelerated rehabilitation of Achilles tendon rupture. However, the optimal knot configuration with PRBT was unknow. The purpose of this study was identify minimum number of half hitches necessary to maintain knot security for PRBT.Methods Using an Instron device we tested the effect of different knot configuration in two kinds of suture threads (Ethibond™ #5 and Ultrabraid™ #2). According to the result of it, we put the optimal knot configuration into Part 1 with PRBT test model and Part 2 with modified PRBT test model, to evaluate whether the optimal knot configuration could complete the cyclic loading test simulated early rehabilitation.Findings In the first part of the study, the optimal knot configuration of Ethibond™ #5 suture thread was the combination of three half hitches and one double throw half knot, and the optimal knot configuration of Ultrabraid™ #2 suture thread was the combination of five half hitches and one double throw half knot. In the second part of the study, only Ultrabraid™ #2 suture thread with optimal knot configuration had finished all test in Part 1.Interpretation The Ultrabraid™ #2 suture thread with optimal knot configuration was suitable for PRBT with early accelerated rehabilitation after Achilles tendon repair.

Options in 3–3.5-mm ports after 2 decades of neonatal endoscopic surgery

After 2 decades of neonatal surgery, endoscopic procedures in this age group are predominantly being performed by 3–3.5-mm instruments. With the neonatal abdominal wall being more elastic and thin compared to adults, improvements in port designs have been addressed to enable their secure placement and avoid dislocation during the procedures. Based on a Google search, variations of commercially available ports designs were identified that were available in 3–3.5-mm work port category. In the 3-mm size category, there were 3 design variations: (a) straight sleeve port, (b) threaded port, and (c) graduated fascial fixation with retention ring. In the 3.5-mm size, two additional design variations: (a) self-retaining port and (b) distal screw anchor port are available. This is the first report to identify 5 designs of 3–3.5-mm port options available for neonatal endoscopic procedures.