Tuning the Biodegradation Rate of Silk Materials via Embedded Enzymes.

Conventional thinking when designing biodegradable materials and devices is to tune the intrinsic properties and morphological features of the material to regulate their degradation rate, modulating traditional factors such as molecular weight and crystallinity. Since regenerated silk protein can be directly thermoplastically molded to generate robust dense silk plastic-like materials, this approach afforded a new tool to control silk degradation by enabling the mixing of a silk-degrading protease into bulk silk material prior to thermoplastic processing. Here we demonstrate the preparation of these silk-based devices with embedded silk-degrading protease to modulate the degradation based on the internal presence of the enzyme to support silk degradation, as opposed to the traditional surface degradation for silk materials. The degradability of these silk devices with and without embedded protease XIV was assessed both in vitro and in vivo. Ultimately, this new process approach provides direct control of the degradation lifetime of the devices, empowered through internal digestion via water-activated proteases entrained and stabilized during the thermoplastic process.

Electrical impedance myography for the early detection of muscle ischemia secondary to compartment syndrome: a study in a rat model.

Acute Compartment Syndrome (ACS) is one of the most devastating orthopedic conditions, affecting any of the body's many compartments, which, if sufficiently severe, may result in disability and amputation. Currently, intra-compartmental pressure measurements serve as the gold standard for diagnosing ACS. Diagnosing limbs at risk for ACS before irreversible damage to muscle and nerve is critical. Standard approaches for diagnosing impending compartment syndrome include clinical evaluation of the limb, such as assessment for "tightness" of the overlying skin, reduced pulses distally, and degree of pain, none of which are specific or sensitive. We have proposed a novel method to detect ACS via electrical impedance myography (EIM), where a weak, high-frequency alternating current is passed between one pair of electrodes through a region of tissue, and the resulting surface voltages are measured via a second pair. We evaluated the ability of EIM to detect early muscle ischemia in an established murine model of compression-induced muscle injury, where we collected resistance, reactance, and their dimensionless product, defined as Relative Injury Index (RII) during the study. Our model generated reproducible hypoxia, confirmed by Hypoxyprobe™ staining of endothelial regions within the muscle. Under conditions of ischemia, we demonstrated a reproducible, stable, and significant escalation in resistance, reactance, and RII values, compared to uninjured control limbs. These data make a reasonable argument for additional investigations into using EIM for the early recognition of muscle hypoperfusion and ischemia. However, these findings must be considered preliminary steps, requiring further pre-clinical and clinical validation.

Effect of intraarticular pressure on glenohumeral kinematics during a simulated abduction motion: a cadaveric study.

BACKGROUND: The current understanding of glenohumeral joint stability is defined by active restrictions and passive stabilizers including naturally-occurring negative intraarticular pressure. Cadaveric specimens have been used to evaluate the role of intraarticular pressure on joint stability, although, while the shoulder's negative intraarticular pressure is universally acknowledged, it has been inconsistently accounted for. HYPOTHESIS: During continuous, passive humeral abduction, releasing the native intraarticular pressure increases joint translation, and restoring this pressure decreases joint translations. STUDY DESIGN: Descriptive Laboratory Study. METHODS: A validated shoulder testing system was used to passively abduct the humerus in the scapular plane and measure joint translations for seven (n = 7) cadaveric specimens. The pressure within the glenohumeral joint was measured via a 25-gauge needle during passive abduction of the arm, which was released and subsequently restored. During motion, the rotator cuff muscles were loaded using stepper motors in a force feedback loop and electromagnetic sensors were used to continuously measure the position of the humerus and scapula. Joint translation was defined according to the instant center of rotation of the glenohumeral head according to the recommendations by the International Society of Biomechanics. RESULTS: Area under the translation versus abduction angle curve suggests that releasing the pressure within the capsule results in significantly less posterior translation of the glenohumeral head as compared to intact (85-90˚, p < 0.05). Posterior and superior translations were reduced after 70˚ of abduction when the pressure within the joint was restored. CONCLUSION: With our testing system employing a smooth continuous passive motion, we were able to show that releasing intraarticular pressure does not have a major effect on the path of humeral head motion during glenohumeral abduction. However, both violating the capsule and restoring intraarticular pressure after releasing alter glenohumeral translations. Future studies should study the effect of simultaneous external rotation and abduction on the relationship between joint motion and IAP, especially in higher degrees of abduction. CLINICAL RELEVANCE: Thoroughly simulating the glenohumeral joint environment in the cadaveric setting may strengthen the conclusions that can be translated from this setting to the clinic.

"Age Is Just a Number": Distal Radius Fractures in Patients Over 75.

Background: Management of distal radius fractures in patients over 65 is a topic of significant study, but there are variations within this group in terms of independence and activity level. This study compares the outcomes of operative distal radius fracture treatment in patients over 75 with those aged 65 to 74, to evaluate the effects of patient demand and advanced age on outcome. Methods: A retrospective review of a single-institution distal radius fracture database was performed. All patients over age 65 were evaluated for inclusion. Patient factors including activity, independence level, and quick disabilities of the arm, shoulder and hand (QuickDASH) score were recorded. Patients were selected for open reduction and internal fixation (ORIF) based on a discussion between the patient and the treating surgeon. Outcome measures including QuickDASH were recorded at 1-year post-injury. Patients aged 65 to 74 and 75 and over were compared to evaluate for demographic, functional, and outcome differences. Results: In all, 75 patients were included in the study. Fifty-one patients were aged 65 to 74, and 24 patients were aged over 75. The majority of patients rated themselves as "completely independent" and "active," the highest levels of each. There was no difference in QuickDASH scores between those patients who rated themselves as completely partially independent, or active versus moderately active. There was no statistically significant difference in QuickDASH or range of motion parameters at final follow-up. Conclusions: This study demonstrates that, in a group of patients with high levels of independence and activity, outcomes are similar in patients aged 65 to 74 and over 75 at 1 year following distal radius ORIF.

Outcomes After Operative Fixation of Vancouver B2 and B3 Type Periprosthetic Fractures.

OBJECTIVES: The incidence of periprosthetic femur fracture in the setting of total hip arthroplasty is steadily increasing. Although the traditional dogma is that loose femoral components must be revised, we propose that in a frail geriatric population, anatomic reduction and fixation of Vancouver B2 and B3 periprosthetic fracture variants can restore stem stability and provide similar outcomes as revision arthroplasty. DESIGN: Retrospective cohort study. SETTING: Level 1 trauma center, tertiary academic medical center. PATIENTS/PARTICIPANTS: We identified 94 patients over 65 years of age with Vancouver B2 and B3 fractures sustained between 2005 and 2019. INTERVENTION: Patients were treated by either open reduction and internal fixation (ORIF) or revision arthroplasty (RA) with or without fixation. MAIN OUTCOME MEASUREMENTS: Outcomes were mortality, time to full weight-bearing after surgery, intraoperative estimated blood loss, perioperative complications, reoperation, subsidence rate, and Patient-Reported Outcomes Measurement Information System pain and physical function scores. RESULTS: A total of 75 (79.8%) ORIF and 19 (20.2%) RA patients were reviewed. One-year mortality for our cohort was 26.3%, and there was no significant difference between groups. Mean time to weight bear and surgical complication rates were similar between groups. The ORIF group had a significantly shorter time to surgery than the RA group. The RA group had greater incidence and amount of subsidence as well as estimated blood loss than the ORIF group. CONCLUSIONS: In geriatric patients with Vancouver B2 and B3 type periprosthetic fractures with known loose stems, ORIF may offer a similarly safe method of treatment than revision arthroplasty. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Longitudinal Changes in Serum Markers of Bone Metabolism and Bone Material Strength in Premenopausal Women with Distal Radial Fracture.

BACKGROUND: Markers of bone metabolism (MBM) play an important role in fracture evaluation, and changes have been associated with increased fracture risk. The purpose of the present study was to describe changes in MBM in premenopausal women with distal radial fractures. METHODS: Premenopausal women with distal radial fractures (n = 34) and without fractures (controls) (n = 39) were recruited. Serum MBM in patients with distal radial fractures were obtained at the time of the initial presentation, 6 weeks, and 3, 6, and 12 months. MBM included 25(OH) vitamin D, PTH, osteocalcin, P1NP, BSAP, CTX, sclerostin, DKK1, periostin, and TRAP5b. Areal bone mineral density (aBMD) was assessed with dual x-ray absorptiometry, and the bone material strength index (BMSi) was assessed with microindentation. RESULTS: Most MBM reached peak levels at 6 weeks after the injury, including osteocalcin (+17.7%), sclerostin (+23.5%), and DKK1 (12.6%). Sclerostin was lower (-27.4%) and DKK1 was higher (+22.2%) at 1 year after the fracture. CTX declined below baseline levels at 6 and 12 months, whereas TRAP5b, BSAP, and periostin did not significantly change. At 12 months, sclerostin was lower (p = 0.003) and DKK1 was higher (p = 0.03) in the distal radial fracture group than in the control group. Greater fracture severity was associated with greater increases in P1NP and BSAP. aBMD and BMSi were not associated with fracture. CONCLUSIONS: Distal radial fractures caused increases in several MBM, which typically peaked at 6 weeks after injury and gradually decreased over 6 months. Sclerostin and DKK1 remained below and above baseline at 1 year, respectively. Increasing fracture severity resulted in larger changes in MBM. aBMD and BMSi did not discriminate between patients with distal radial fractures and controls. Continued efforts to identify markers of skeletal fragility in young women are warranted to mitigate future fracture risk. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

3D Bioprinted Bacteriostatic Hyperelastic Bone Scaffold for Damage-Specific Bone Regeneration.

Current strategies for regeneration of large bone fractures yield limited clinical success mainly due to poor integration and healing. Multidisciplinary approaches in design and development of functional tissue engineered scaffolds are required to overcome these translational challenges. Here, a new generation of hyperelastic bone (HB) implants, loaded with superparamagnetic iron oxide nanoparticles (SPIONs), are 3D bioprinted and their regenerative effect on large non-healing bone fractures is studied. Scaffolds are bioprinted with the geometry that closely correspond to that of the bone defect, using an osteoconductive, highly elastic, surgically friendly bioink mainly composed of hydroxyapatite. Incorporation of SPIONs into HB bioink results in enhanced bacteriostatic properties of bone grafts while exhibiting no cytotoxicity. In vitro culture of mouse embryonic cells and human osteoblast-like cells remain viable and functional up to 14 days on printed HB scaffolds. Implantation of damage-specific bioprinted constructs into a rat model of femoral bone defect demonstrates significant regenerative effect over the 2-week time course. While no infection, immune rejection, or fibrotic encapsulation is observed, HB grafts show rapid integration with host tissue, ossification, and growth of new bone. These results suggest a great translational potential for 3D bioprinted HB scaffolds, laden with functional nanoparticles, for hard tissue engineering applications.

Comparison of Patellofemoral Kinematics and Stability After Medial Patellofemoral Ligament and Medial Quadriceps Tendon-Femoral Ligament Reconstruction.

BACKGROUND: There is a lack of evidence regarding the optimum extensor-sided fixation method for medial patellofemoral ligament (MPFL) reconstruction. There is increased interest in avoiding patellar drilling via soft tissue-only fixation to the distal quadriceps, thus reconstructing the medial quadriceps tendon-femoral ligament (MQTFL). The biomechanical implications of differing extensor-sided fixation constructs remain unknown. HYPOTHESIS: The null hypothesis was there would be no differences between traditional MPFL reconstruction and MQTFL reconstruction with respect to resistance to lateral translation, patellar position, or patellofemoral contact pressures. STUDY DESIGN: Controlled laboratory study. METHODS: Nine adult knee specimens were mounted on a jig that applied static, physiologic loads to the quadriceps tendons. Patellar position and orientation, knee flexion angle, and patellofemoral pressure were recorded at 8 different flexion angles between 0° and 110°. Additionally, a lateral patellar excursion test was conducted wherein a load was applied directly to the patella in the lateral direction with the knee at 30° of flexion and subjected to 2-N quadriceps loads. Testing was conducted under 4 conditions: intact, transected MPFL, MQTFL reconstruction, and MPFL reconstruction. For MQTFL reconstruction, the surgical technique established by Fulkerson was employed. For MPFL reconstruction, a traditional technique was utilized. RESULTS: The patellar excursion test showed no significant difference between the MQTFL and intact states with respect to lateral translation. MPFL reconstruction led to significantly less lateral translation (P < .05) than all other states. There were no significant differences between MPFL and MQTFL reconstructions with respect to peak patellofemoral contact pressure. MPFL and MQTFL reconstructions both resulted in increased internal rotation of the patella with the knee in full extension. CONCLUSION: Soft tissue-only extensor-sided fixation to the distal quadriceps (MQTFL) during patella stabilization appears to re-create native stability in this time 0 cadaver model. Fixation to the patella (MPFL) was associated with increased resistance to lateral translation. CLINICAL RELEVANCE: Evolving anatomic knowledge and concern for patellar fracture has led to increased interest in MQTFL reconstruction. Both MQTFL and MPFL reconstructions restored patellofemoral stability to lateral translation without increasing contact pressures under appropriate graft tensioning, with MQTFL more closely restoring native resistance to lateral translation at the time of surgery.

Effect of rotator cuff muscle activation on glenohumeral kinematics: A cadaveric study.

Healthy shoulder function requires the coordination of the rotator cuff muscles to maintain the humeral head's position in the glenoid. While glenohumeral stability has been studied in various settings, few studies have characterized the effect of dynamic rotator cuff muscle loading on glenohumeral translation during shoulder motion. We hypothesize that dynamic rotator cuff muscle activation decreases joint translation during continuous passive abduction of the humerus in a cadaveric model of scapular plane glenohumeral abduction. The effect of different rotator cuff muscle activity on glenohumeral translation was assessed using a validated shoulder testing system. The Dynamic Load profile is a novel approach, based on musculoskeletal modeling of human subject motion. Passive humeral elevation in the scapular plane was applied via the testing system arm, while the rotator cuff muscles were activated according to the specified force profiles using stepper motors and a proportional control feedback loop. Glenohumeral translation was defined according to the International Society of Biomechanics. The Dynamic load profile minimized superior translation of the humeral head relative to the conventional loading profiles. The total magnitude of translation was not significantly different (0.805) among the loading profiles suggesting that the compressive forces from the rotator cuff primarily alter the direction of humeral head translation, not the magnitude. Rotator cuff muscle loading is an important element of cadaveric shoulder studies that must be considered to accurately simulate glenohumeral motion. A rotator cuff muscle activity profile based on human subject muscle activity reduces superior glenohumeral translation when compared to previous RC loading profiles.

Complications After Upper Extremity Surgery in Solid Organ Transplant Patients.

PURPOSE: To determine the rate of and risk factors for complications in solid organ transplant (SOT) patients who have had surgery of the upper extremity. METHODS: All SOT recipients who had an upper extremity procedure performed by 1 of 6 surgeons at our institution were identified from 2006 to 2018. Demographic data, transplant date and type, upper extremity surgery procedure and date, antirejection medications, American Society of Anesthesiologists Physical Status Classification System (ASA) score, and complications were recorded. Complications were defined as any surgical complication within 1 year and any medical complication within the first 30 days after surgery. Complications were categorized according to the Clavien-Dindo classification system. RESULTS: Fifty-one upper extremity procedures in 32 SOT patients were included. Of the 51 procedures, 21 were complicated, for an overall complication rate of 41%. Surgical complications occurred equally before and after 30 days with infection being the most common. Only 1 of the procedures resulting in surgical site infection had an implant (temporary K-wire fixation). The majority of complications were grade II, and there were no grade IV or V complications. Age, ASA score, type or number of SOT, and immunosuppressive regimens were similar between complicated and noncomplicated procedures. Procedures involving male patients were more likely to be complicated than those involving female patients. CONCLUSIONS: Complications after upper extremity operations are common in SOT patients, and surgical complications often occur after 30 days. Surgeons should counsel this population that they carry a higher complication risk than the general population and may require longer-term monitoring after surgery. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Outcomes and Complications Following Volar and Dorsal Osteotomy for Symptomatic Distal Radius Malunions: A Comparative Study.

PURPOSE: To compare patient-reported outcomes, functional outcomes, radiographic alignment, and complications of volar versus dorsal corrective osteotomies as the treatment for symptomatic distal radius malunions. METHODS: We performed a retrospective review of all patients who underwent a distal radius corrective osteotomy with either a volar or dorsal approach and plating at 1 of 3 institutions between 2005 and 2017. Demographic data, type of surgical treatment, and radiographs were examined. Outcomes were Quick-Disabilities of the Arm, Shoulder, and Hand (QuickDASH) function scores and radius union scoring system as well as major and minor complications. RESULTS: We included 53 cases (37 volar osteotomies and 16 dorsal osteotomies). Postoperative follow-up from the time of surgery to last QuickDASH score was 84.6 months (range, 12-169.4 months). Compared with the dorsal osteotomy group, the volar osteotomy group demonstrated a better postoperative flexion-extension arc (94.9° vs 72.9°, respectively), pronation-supination arc (146.2° vs 124.9°, respectively), and last QuickDASH scores (6.65 vs 12.87), respectively. Radiographically, there was no difference noted in radial height, radial inclination, or volar tilt in the immediate postoperative and last radiographs. There was a higher rate of complications in the dorsal osteotomy group (8 cases [50% of patients]) compared with the volar osteotomy group (7 cases [18.9% of patients]), including a higher rate of hardware removal. CONCLUSIONS: For patients with symptomatic malunions of the distal radius, the volar and dorsal approaches both resulted in improvement in QuickDASH scores and range of motion. Volar plating resulted in slightly better QuickDASH scores and fewer complications compared with dorsal plating. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Tendon lengthening after achilles tendon rupture-passive effects on the ankle joint in a cadaveric pilot study simulating weight bearing.

BACKGROUND: In recent years, primary Achilles tendon ruptures have increased due to the aging population's participation in physically demanding activities. These injuries commonly occur during recreational sports and frequently lead to a long-term reduction in activity despite treatment. Non-operative methods of treatment for Achilles tendon ruptures may result in the Achilles healing in a lengthened position compared to the pre-injury state. This study uses a cadaveric model that simulates static weight bearing to explore the effect of a lengthened Achilles tendon on ankle joint load distribution. METHODS: Five lower limb cadaveric specimens were placed on a custom jig, where a 334 N (75 lb) load was applied at the femoral head, and the foot was supported against a plate to simulate static double-leg stance. A pressure mapping sensor was inserted into the ankle joint. A percutaneous triple hemiresection tendo-Achilles lengthening procedure (Hoke procedure) was performed on each specimen to simulate tendon lengthening after conservative treatment. Contact pressure, peak pressure, and center-of-pressure were measured for native and tendon-lengthened conditions. RESULTS: Tendon rupture did not significantly alter average contact pressure, peak contact pressures, or center-of-pressure in the ankle joint compared with native tendon. CONCLUSION: Achilles lengthening does not significantly change contact pressures of the ankle joint in this model . This result suggests that the passive restraint on ankle joint translation imposed by the Achilles tendon is minimal without muscle activation.

Thermoplastic moulding of regenerated silk.

Early insights into the unique structure and properties of native silk suggested that ß-sheet nanocrystallites in silk would degrade prior to melting when subjected to thermal processing. Since then, canonical approaches for fabricating silk-based materials typically involve solution-derived processing methods, which have inherent limitations with respect to silk protein solubility and stability in solution, and time and cost efficiency. Here we report a thermal processing method for the direct solid-state moulding of regenerated silk into bulk 'parts' or devices with tunable mechanical properties. At elevated temperature and pressure, regenerated amorphous silk nanomaterials with ultralow ß-sheet content undergo thermal fusion via molecular rearrangement and self-assembly assisted by bound water to form a robust bulk material that retains biocompatibility, degradability and machinability. This technique reverses presumptions about the limitations of direct thermal processing of silk into a wide range of new material formats and composite materials with tailored properties and functionalities.

The utility of post-operative hip radiographs in patients treated with hip hemiarthroplasty for femoral neck fractures.

BACKGROUND: Patients treated with hip hemiarthroplasty for low energy femoral neck fractures routinely undergo hip radiographs at each postoperative clinic visit regardless of history and physical findings. No studies to date have evaluated the effectiveness of this accepted practice. The goal of this study was to identify the postoperative utility of both history and physical (H/P) and hip radiographs in the treatment course of patients treated with hip hemiarthroplasty for low energy femoral neck fractures. METHODS: A retrospective chart review was performed on consecutive patients treated with hip hemiarthroplasty for low energy femoral neck fractures. An abnormal H/P and hip radiographs as well as a change in treatment course were recorded at each clinic or emergency department visit. RESULTS: Five hundred and eighty-three patients met inclusion criteria, consisting of 1177 clinic and 50 emergency department (ED) visits. An abnormal radiograph in the presence of a normal H/P did not lead to a change in treatment course. An abnormal H/P alone changed treatment course in 28 (3%) clinic visits and 18 (36%) ED visits. An abnormal H/P and the presence of an abnormal hip radiograph changed the treatment course in 23 (2%) clinic visits and 18 (36%) ED visits. In only one case - 0.3% of abnormal radiographs or 0.08% of 1177 clinic visits - did an abnormal hip radiograph change treatment course in the setting of an abnormal H/P within 6 months from surgery. The average cost of a series of hip and pelvis radiographs was $242. CONCLUSIONS: Abnormal radiographs do not change treatment course in the presence of a normal H/P. Hip radiographs obtained in clinic within 6 months of surgery rarely lead to a change in treatment course and thereby are a source of excess cost and radiation exposure to the patient.

Diagnostic Modalities for Acute Compartment Syndrome of the Extremities: A Systematic Review.

IMPORTANCE: Acute compartment syndrome (ACS) can cause catastrophic tissue damage leading to permanent muscle and nerve loss. Acute compartment syndrome is a clinical diagnosis, with intracompartmental pressure (ICP) used in equivocal cases. There are no reliable diagnostic methods. The clinical evaluation is impossible to standardize, and the threshold for ICP has been known to be unreliable; thus, guidelines for diagnosis can result in overtreatment or delayed diagnosis. OBJECTIVE: To present and review the advantages and disadvantages of each diagnostic modality and identify gaps that need to be addressed in the future and to review the most used and appropriate animal and human ACS models. EVIDENCE REVIEW: We included clinical studies and animal models investigating diagnostic modalities for ACS of the extremities. A MEDLINE and Web of Science search was performed. The protocol for the study was registered on PROSPERO (CRD42017079266). We assessed the quality of the clinical studies with Newcastle-Ottawa scale and reported level of evidence for each article. FINDINGS: Fifty-one articles were included in this study, reporting on 38 noninvasive and 35 invasive modalities. Near-infrared spectroscopy and direct ICP measurement using a Stryker device were the most common, respectively. Cadaveric studies used saline infusions to create an ACS model. Most studies with human participants included injured patients with acquired ACS or at risk of developing ACS. In healthy human participants, tourniquets formed the most commonly used ACS model. Application of tourniquets and infusion of saline or albumin were the most used ACS models among animal studies. CONCLUSIONS AND RELEVANCE: This article reports on the most common as well as many new and modified diagnostic modalities, which can serve as inspiration for future investigations to develop more effective and efficient diagnostic techniques for ACS. Future studies on diagnostic modalities should include the development of tools for continuous assessment of ICP to better identify the earliest alterations suggestive of impending ACS. With the advent of such technologies, it may be possible to develop far less aggressive and more effective approaches for early detection of ACS.

The Effect of Gentamycin in the Irrigating Solution to Prevent Joint Infection after Anterior Cruciate Ligament (ACL) Reconstruction.

BACKGROUND: Arthroscopic reconstruction of ACL is an effective method to restore knee stability after ACL rupture. Postoperative septic arthritis (SA) is very uncommon while the incidence of serious complications range between 0.14% and 1.8%. Some of the devastating consequences of septic arthritis can encompass hyaline cartilage damage, arthrofibrosis, and in rare cases amputation. The purpose of this study was to evaluate the effect of gentamicin irrigation solutions as a process to restrain septic arthritis following arthroscopic ACL reconstruction. METHODS: In this retrospective cohort study, 1464 patients who underwent ACL reconstruction with hamstring tendon autograft in our institution over 7 years (February 2008 to January 2015) were included. The patients were divided into two groups based on the type of intra-articular irrigation solution used during the surgery. Patients in Group 1 (Saline) received intra-articular irrigation with normal saline (0.9 % sodium chloride) solution, while those in Group 2 (Gentamycin) received intra-articular irrigation with gentamicin (80 mg/L) added to the normal saline solution. Data about postoperative infection, its course, management, and outcome were obtained from patients' records. RESULTS: Seven patients developed SA, four of whom were from SALINE group (2.2%) and three from Gentamycin group (0.23%). The incidence rate of SA after arthroscopic ACL reconstruction was significantly lower (P <0.05) when irrigated with gentamicin solution than merely with saline solution. CONCLUSION: Gentamicin irrigation solution has a preservative and protective effect against SA development following arthroscopic ACL reconstruction. We recommend evaluating this technique as a way in order to depreciate the prevalence of SA after ACL reconstruction.

Comparative Efficacy and Safety of Nonsurgical Treatment Options for Enthesopathy of the Extensor Carpi Radialis Brevis: A Systematic Review and Meta-analysis of Randomized Placebo-Controlled Trials.

BACKGROUND: Numerous treatment options have been proposed for enthesopathy of the extensor carpi radialis brevis (eECRB). PURPOSE: To (1) compare the efficacy and safety of nonsurgical treatment options for eECRB described in randomized placebo-controlled trials at short-term, midterm, and long-term follow-up and (2) evaluate outcomes in patients receiving placebo. STUDY DESIGN: Systematic review and meta-analysis. METHODS: Following PRISMA guidelines, 4 electronic databases were searched for randomized placebo-controlled trials for eECRB. Studies reporting visual analog scale (VAS) for pain scores and/or grip strength were included. Random- or fixed-effects meta-analysis was employed to compare treatments with at least 2 eligible studies using the standardized mean difference and odds ratio. The study protocol was registered at PROSPERO (ID: CRD42018075009). RESULTS: Thirty-six randomized placebo-controlled trials, evaluating 11 different treatment modalities, with a total of 2746 patients were included. At short-term follow-up, only local corticosteroid injection improved pain; however, it was associated with pain worse than placebo at long-term follow-up. At midterm follow-up, laser therapy and local botulinum toxin injection improved pain. At long-term follow-up, extracorporeal shock wave therapy provided pain relief. With regard to grip strength, only laser therapy showed better outcomes in comparison with placebo. While there was no difference among various treatments in the odds ratio of an adverse event, they all increased adverse events compared with placebo. In placebo-receiving patients, a sharp increase in the percentage of patients reporting mild pain or less was observed from 2% at short-term follow-up to 92% at midterm follow-up. CONCLUSION: Most patients experienced pain resolution after receiving placebo within 4 weeks of follow-up. At best, all treatments provided only small pain relief while increasing the odds of adverse events. Therefore, if clinicians are inclined to provide a treatment for particular patients, they may consider a pain relief regimen for the first 4 weeks of symptom duration. Patient-specific factors should be considered when deciding on treatment or watchful waiting.

Rat Model of Adhesive Capsulitis of the Shoulder.

This proposal aims to create an in vivo rat model of adhesive capsulitis for researching potential treatment options for this condition and other etiologies of comparable arthrofibrosis. The model includes extra-articular fixation of the shoulder in rats via scapular to humeral suturing, resulting in a secondary contracture without invading the intra-articular space and resulting in decreased rotational ROM and increased joint stiffness. We used 10 Sprague-Dawley rats for the purpose of this study. Baseline ROM measurements were taken before glenohumeral immobilization. The rats were subjected to 8 weeks of immobilization before the fixation sutures were removed and changes in ROM and joint stiffness were evaluated. To evaluate whether immobilization resulted in a significant reduction in ROM, changes in kinematics were calculated. ROM was measured at each time point in the follow-up period and was compared to the baseline internal and external ROM measurements. In order to evaluate the stiffness, joint kinetics were calculated by determining the differences in torque (text and tint ) needed to reach the initial external rotation of 60° and initial internal rotation of 80°. After the removal of the extra-articular suture fixation on follow-up day 0, we found a 63% decrease in total ROM compared to baseline. We observed continuous improvement until week 5 of follow-up, with the progress slowing down around a 19% restriction. On week 8 of follow-up, there was still an 18% restriction of ROM. Additionally, on follow-up day 0, we found the torque increased by 13.3 Nmm when compared to baseline. On week 8, the total torque was measured to be 1.4 ± 0.2 Nmm higher than initial measurements. This work introduces a rat model of shoulder adhesive capsulitis with lasting reduced ROM and increased stiffness.

Pressure Distribution in the Ankle and Subtalar Joint With Routine and Oversized Foot Orthoses.

BACKGROUND: Foot orthoses are used to treat many disorders that affect the lower limb. These assistive devices have the potential to alter the forces, load distribution, and orientation within various joints in the foot and ankle. This study attempts to quantify the effects of orthoses on the intra-articular force distribution of the ankle and subtalar joint using a cadaveric testing jig to simulate weight bearing. METHODS: Five lower-limb cadaveric specimens were placed on a custom jig, where a 334-N (75-lb) load was applied at the femoral head, and the foot was supported against a plate to simulate double-leg stance. Pressure-mapping sensors were inserted into the ankle and subtalar joint. Mean pressure, peak pressure, contact area, and center of force were measured in both the ankle and subtalar joints for barefoot and 2 medial foot orthosis conditions. The 2 orthosis conditions were performed using (1) a 1.5-cm-height wedge to simulate normal orthoses and (2) a 3-cm-height wedge to simulate oversized orthoses. RESULTS: The contact area experienced in the subtalar joint significantly decreased during 3-cm orthotic posting of the medial arch, but neither orthosis had a significant effect on the spatial mean pressure or peak pressure experienced in either joint. CONCLUSION: The use of an oversized orthosis could lead to a decrease in the contact area and alterations in the distribution of pressure within the subtalar joint. CLINICAL RELEVANCE: The use of inappropriate orthoses could negatively impact the force distribution in the lower limb.