Sensory Neuron-Specific Deletion of Tropomyosin Receptor Kinase A (TrkA) in Mice Abolishes Osteoarthritis (OA) Pain via NGF/TrkA Intervention of Peripheral Sensitization.

Tropomyosin receptor kinase A (TrkA/NTRK1) is a high-affinity receptor for nerve growth factor (NGF), a potent pain mediator. NGF/TrkA signaling elevates synovial sensory neuronal distributions in the joints and causes osteoarthritis (OA) pain. We investigated the mechanisms of pain transmission as to whether peripheral sensory neurons are linked to the cellular plasticity in the dorsal root ganglia (DRG) and are critical for OA hyperalgesia. Sensory neuron-specific deletion of TrkA was achieved by tamoxifen injection in 4-week-old TrkAfl/fl;NaV1.8CreERT2 (Ntrk1 fl/fl;Scn10aCreERT2) mice. OA was induced by partial medial meniscectomy (PMM) in 12-week-old mice, and OA-pain-related behavior was analyzed for 12 weeks followed by comprehensive histopathological examinations. OA-associated joint pain was markedly improved without cartilage protection in sensory-neuron-specific conditional TrkA knock-out (cKO) mice. Alleviated hyperalgesia was associated with suppression of the NGF/TrkA pathway and reduced angiogenesis in fibroblast-like synovial cells. Elevated pain transmitters in the DRG of OA-induced mice were significantly diminished in sensory-neuron-specific TrkA cKO and global TrkA cKO mice. Spinal glial activity and brain-derived neurotropic factor (BDNF) were significantly increased in OA-induced mice but were substantially eliminated by sensory-neuron-specific deletion. Our results suggest that augmentation of NGF/TrkA signaling in the joint synovium and the peripheral sensory neurons facilitate pro-nociception and centralized pain sensitization.

Biomechanical Performance of Medial Row Suture Placement Relative to the Musculotendinous Junction in Transosseous Equivalent Suture Bridge Double-Row Rotator Cuff Repair.

PURPOSE: To compare the biomechanical performance of medial row suture placement relative to the musculotendinous junction (MTJ) in a cadaveric transosseous equivalent suture bridge (TOE-SB) double-row (DR) rotator cuff repair (RCR) model. METHODS: A TOE-SB DR technique was used to reattach experimentally created supraspinatus tendon tears in 9 pairs of human cadaveric shoulders. The medial row sutures were passed either near the MTJ (MTJ group) or 10 mm lateral to the MTJ (rotator cuff tendon [RCT] group). After the supraspinatus repair, the specimens underwent cyclic loading and load to failure tests. The localized displacement of the markers affixed to the tendon surface was measured with an optical tracking system. RESULTS: The MTJ group showed a significantly higher (P = .03) medial row failure (5/9; 3 during cyclic testing and 2 during load to failure testing) compared with the RCT group (0/9). The mean number of cycles completed during cyclic testing was lower in the MTJ group (77) compared with the RCT group (100; P = .07) because 3 specimens failed in the MTJ group during cyclic loading. There were no significant differences between the 2 study groups with respect to biomechanical properties during the load to failure testing. CONCLUSIONS: In a cadaveric TOE-SB DR RCR model, medial row sutures through the MTJ results in a significantly higher rate of medial row failure. CLINICAL RELEVANCE: In rotator cuff tears with tendon tissue loss, passage of medial row sutures through the MTJ should be avoided in a TOE-SB RCR technique because of the risk of medial row failure.

Reverse total shoulder arthroplasty in patients of varying body mass index.

BACKGROUND: Body mass index (BMI) is an independent predictor of complications after hip and knee arthroplasty. Whether similar trends apply to patients undergoing reverse total shoulder arthroplasty (RTSA) is unknown. METHODS: A retrospective review of primary RTSAs with a minimum 90-day follow-up were included. Complications were classified as major or minor and medical or surgical. Patients were classified into 3 groups: normal BMI (BMI <25 kg/m(2)), overweight or mildly obese (BMI 25-35 kg/m(2)), and moderately or severely obese (BMI >35 kg/m(2)). RESULTS: Of the 119 patients met our inclusion criteria, 30 (25%) had a BMI of less than 25 kg/m(2); 65 (55%) had a BMI of 25 to 35 kg/m(2), and 24 (20%) had BMI exceeding 35 kg/m(2). Complications occurred in 30 patients (25%), comprising major in 11 (9%), minor in 19 (16%), surgical in 21 (18%), and medical in 14 (12%). The most common surgical complications were acute blood loss anemia requiring transfusion (8.4%) and dislocation (4.2%). The most common medical complications were atelectasis (2.5%) and acute renal insufficiency (2.5%). Patients with a BMI exceeding 35 kg/m(2) had a significantly higher overall complication rate (P < .05) and intraoperative blood loss (P = .05) than the other groups. Patients with BMI of less than 25 kg/m(2) had a greater overall complication rate than those with a BMI of 25 to 35 kg/m(2) (P < .05). Multivariate regression analysis demonstrated BMI was the only significant determinant of overall complication rates and medical complication rates (P < .05). CONCLUSION: Patients with a BMI exceeding 35 kg/m(2) (severely obese) or a BMI of less than 25 kg/m(2) have higher rates of complication after RTSA.

Predictors of early complications of total shoulder arthroplasty.

The authors hypothesized that age, body mass index (BMI), and medical comorbidities (graded with the Charleson Comorbidiy index [CCI]) could be used to predict early complications after TSA. The authors performed a retrospective review of primary TSAs with a minimum of 90-day follow-up. One hundred twenty-seven patients met the inclusion criteria. Complications occurred in 12 (9.4%) of patients. Major complications occurred in 1 patient (0.8%), medical in 8 (6.3%), and surgical in 4 (3.1%). CCI significantly correlated with complication rates and multivariate regression analysis demonstrated CCI to be the only significant determinant of overall complication rates (P = 0.005) and medical complication rates (P = 0.015). While BMI subgroup did not affect complication rates, transfusion rates, intra-operative blood loss, or operative time, our study may have been underpowered for this variable.

Repurposing Mitomycin C in Combination with Pentamidine or Gentamicin to Treat Infections with Multi-Drug-Resistant (MDR) Pseudomonas aeruginosa.

The aims of this study were (i) to determine if the combination of mitomycin C with pentamidine or existing antibiotics resulted in enhanced efficacy versus infections with MDR P. aeruginosa in vivo; and (ii) to determine if the doses of mitomycin C and pentamidine in combination can be reduced to levels that are non-toxic in humans but still retain antibacterial activity. Resistant clinical isolates of P. aeruginosa, a mutant strain over-expressing the MexAB-OprM resistance nodulation division (RND) efflux pump and a strain with three RND pumps deleted, were used. MIC assays indicated that all strains were sensitive to mitomycin C, but deletion of three RND pumps resulted in hypersensitivity and over-expression of MexAB-OprM caused some resistance. These results imply that mitomycin C is a substrate of the RND efflux pumps. Mitomycin C monotherapy successfully treated infected Galleria mellonella larvae, albeit at doses too high for human administration. Checkerboard and time-kill assays showed that the combination of mitomycin C with pentamidine, or the antibiotic gentamicin, resulted in synergistic inhibition of most P. aeruginosa strains in vitro. In vivo, administration of a combination therapy of mitomycin C with pentamidine, or gentamicin, to G. mellonella larvae infected with P. aeruginosa resulted in enhanced efficacy compared with monotherapies for the majority of MDR clinical isolates. Notably, the therapeutic benefit conferred by the combination therapy occurred with doses of mitomycin C close to those used in human medicine. Thus, repurposing mitomycin C in combination therapies to target MDR P. aeruginosa infections merits further investigation.

Nanoparticle-based inhibition of vascular endothelial growth factor receptors alleviates osteoarthritis pain and cartilage damage.

Osteoarthritis (OA) is characterized by cartilage damage, inflammation, and pain. Vascular endothelial growth factor receptors (VEGFRs) have been associated with OA severity, suggesting that inhibitors targeting these receptors alleviate pain (via VEGFR1) or cartilage degeneration (via VEGFR2). We have developed a nanoparticle-based formulation of pazopanib (Votrient), an FDA-approved anticancer drug that targets both VEGFR1 and VEGFR2 (Nano-PAZII). We demonstrate that a single intraarticular injection of Nano-PAZII can effectively reduce joint pain for a prolonged time without substantial side effects in two different preclinical OA rodent models involving either surgical (upon partial medial meniscectomy) or nonsurgical induction (with monoiodoacetate). The injection of Nano-PAZII blocks VEGFR1 and relieves OA pain by suppressing sensory neuronal ingrowth into the knee synovium and neuronal plasticity in the dorsal root ganglia and spinal cord. Simultaneously, the inhibition of VEGFR2 reduces cartilage degeneration. These findings provide a mechanism-based disease-modifying drug strategy that addresses both pain symptoms and cartilage loss in OA.

Loss of PKCδ/Prkcd prevents cartilage degeneration in joints but exacerbates hyperalgesia in an experimental osteoarthritis mouse model.

Pain is the prime symptom of osteoarthritis (OA) that directly affects the quality of life. Protein kinase Cδ (PKCδ/Prkcd) plays a critical role in OA pathogenesis; however, its significance in OA-related pain is not entirely understood. The present study investigated the functional role of PKCδ in OA pain sensation. OA was surgically induced in control (Prkcdfl/fl), global- (Prkcdfl/fl; ROSACreERT2), and sensory neuron-specific conditional knockout (cKO) mice (Prkcdfl/fl; NaV1.8/Scn10aCreERT2) followed by comprehensive analysis of longitudinal behavioral pain, histopathology and immunofluorescence studies. GlobalPrkcd cKO mice prevented cartilage deterioration by inhibiting matrix metalloproteinase-13 (MMP13) in joint tissues but significantly increased OA pain. Sensory neuron-specificdeletion of Prkcd in mice did not protect cartilage from degeneration but worsened OA-associated pain. Exacerbated pain sensitivity observed in global- and sensory neuron-specific cKO of Prkcd was corroborated with markedly increased specific pain mediators in knee synovium and dorsal root ganglia (DRG). These specific pain markers include nerve growth factor (NGF) and vascular endothelial growth factor (VEGF), and their cognate receptors, including tropomyosin receptor kinase A (TrkA) and vascular endothelial growth factor receptor-1 (VEGFR1). The increased levels of NGF/TrkA and VEGF/VEGFR1 were comparable in both global- and sensory neuron-specific cKO groups. These data suggest that the absence of Prkcd gene expression in the sensory neurons is strongly associated with OA hyperalgesia independent of cartilage protection. Thus, inhibition of PKCδ may be beneficial for cartilage homeostasis but could aggravate OA-related pain symptoms.

Targeting Vascular Endothelial Growth Factor Receptors as a Therapeutic Strategy for Osteoarthritis and Associated Pain.

Pain is the major reason that patients suffering from osteoarthritis (OA) seek medical care. We found that vascular endothelial growth factors (VEGFs) mediate signaling in OA pain pathways. To determine the specific contributions of VEGFs and their receptors (VEGFRs) to joint pathology and pain transmission during OA progression, we studied intra-articular (IA) injections of VEGF ligands into murine knee joints. Only VEGF ligands specific for the activation of VEGFR1, but not VEGFR2, induced allodynia within 30 min. Interventions in OA by inhibitors of VEGFRs were done in vivo using a preclinical murine OA model by IA injections of selective inhibitors of VEGFR1/VEGFR2 kinase (pazopanib) or VEGFR2 kinase (vandetanib). OA phenotypes were evaluated using pain-associated murine behavioral tests and histopathologic analyses. Alterations in VEGF/VEGFR signaling by drugs were determined in knee joints, dorsal root ganglia, and spinal cord by immunofluorescence microscopy. Pazopanib immediately relieved OA pain by interfering with pain transmission pathways. Pain reduction by vandetanib was mainly due to the inhibition of cartilage degeneration by suppressing VEGFR2 expression. In conclusion, IA administration of pazopanib, which simultaneously inhibits VEGFR1 and VEGFR2, can be developed as an ideal OA disease-modifying drug that rapidly reduces joint pain and simultaneously inhibits cartilage degeneration.

Brachial plexus blocks for upper extremity orthopaedic surgery.

Regional anesthesia of the upper extremity has several clinical applications and is reported to have several advantages over general anesthesia for orthopaedic surgery. These advantages, such as improved postoperative pain, decreased postoperative opioid administration, and reduced recovery time, have led to widespread acceptance of a variety of regional nerve blocks. Interscalene block is the most commonly used block for shoulder surgery. Other brachial plexus nerve blocks used for orthopaedic surgery of the upper extremity are supraclavicular, infraclavicular, and axillary. Several practical and theoretical aspects of regional nerve blocks must be considered to optimize the beneficial effects and minimize the risk of complications.

A review of modern management of lateral epicondylitis.

Lateral epicondylitis, or tennis elbow, is the most common cause of elbow pain. This degenerative condition can manifest as an acute process lasting < 3 months or a chronic process often refractory to treatment. Symptom resolution occurs in 70% to 80% of patients within the first year. A "watch-and-wait" approach can be an appropriate treatment option, although physical therapy has been shown to be an effective first-line therapy. Corticosteroids, while providing relief of pain in the acute setting, may be detrimental to recovery in the long term. Platelet-rich plasma injections, although recently well publicized, have not been proven by well-controlled clinical trials to be effective therapy. For patients with symptoms refractory to conservative management, surgical intervention has shown to be a successful treatment modality.

Lactobacillus acidophilus Mitigates Osteoarthritis-Associated Pain, Cartilage Disintegration and Gut Microbiota Dysbiosis in an Experimental Murine OA Model.

To test probiotic therapy for osteoarthritis (OA), we administered Lactobacillus acidophilus (LA) by oral gavage (2×/week) after induction of OA by partial medial meniscectomy (PMM). Pain was assessed by von Frey filament and hot plate testing. Joint pathology and pain markers were comprehensively analyzed in knee joints, spinal cords, dorsal root ganglia and distal colon by Safranin O/fast green staining, immunofluorescence microscopy and RT-qPCR. LA acutely reduced inflammatory knee joint pain and prevented further OA progression. The therapeutic efficacy of LA was supported by a significant reduction of cartilage-degrading enzymes, pain markers and inflammatory factors in the tissues we examined. This finding suggests a likely clinical effect of LA on OA. The effect of LA treatment on the fecal microbiome was assessed by 16S rRNA gene amplicon sequencing analysis. LA significantly altered the fecal microbiota compared to vehicle-treated mice (PERMANOVA p < 0.009). Our pre-clinical OA animal model revealed significant OA disease modifying effects of LA as reflected by rapid joint pain reduction, cartilage protection, and reversal of dysbiosis. Our findings suggest that LA treatment has beneficial systemic effects that can potentially be developed as a safe OA disease-modifying drug (OADMD).

Gut-microbiota modulation: The impact of thegut-microbiotaon osteoarthritis.

Osteoarthritis (OA) is one of the most common medical conditions affecting > 300 million people globally which represents the formidable public health challenge. Despite its clinical and financial ramifications, there are currently no approved disease modifying OA drugs available and symptom palliation is the only alternative. Currently, the amount of data on the human intestinal microbiome is growing at a high rate, both in health and in various pathological conditions. With an increase in the amount of the accumulated data, there is an expanded understanding that the microbiome provides compelling evidence of a link between thegut microbiomeand development ofOA. The microbiota management tools of probiotics and/or prebiotics or symbiotic have been developed and indeed, commercialized over the past few decades with the expressed purpose of altering the microbiota within the gastrointestinal tract which could be a potentially novel intervention to tackle or prevent OA. However, the mechanisms how intestinal microbiota affects the OA pathogenesis are still not clear and further research targeting specific gut microbiota or its metabolites is still needed to advance OA treatment strategies from symptomatic management to individualized interventions of OA pathogenesis. This article provides an overview of the various preclinical and clinical studies using probiotics and prebiotics as plausible therapeutic options that can restore the gastrointestinal microbiota and its impact on the OA pathogenesis. May be in the near future the targeted alterations of gut microbiota may pave the way for developing new interventions to prevent and treat OA.

Interexaminer reliability of a leg length analysis procedure among novice and experienced practitioners.

OBJECTIVE: The purpose of this study was to evaluate the interexaminer reliability of a leg length analysis protocol between an experienced chiropractor and an inexperienced chiropractic student who has undergone an intensive training program. METHODS: Fifty participants, aged from 18 to 55 years, were recruited from the New Zealand College of Chiropractic teaching clinic. An experienced chiropractor and a final-year chiropractic student were the examiners. Participants were examined for leg length inequality in the prone straight leg and flexed knee positions by each of the examiners. The examiners were asked to record which leg appeared shorter in each position. Examiners were blinded to each other's findings. kappa statistics and percent agreement between examiners were used to assess interexaminer reliability. RESULTS: kappa analysis revealed substantial interexaminer reliability in both leg positions and also substantial agreement when straight and flexed knee results were combined for each participant. kappa scores ranged from 0.61, with 72% agreement, for the combined positions to 0.70, with 87% agreement, for the extended knee position. All of the kappa statistics analyzed surpassed the minimal acceptable standard of 0.40 for a reliability trial such as this. CONCLUSION: This study revealed good interexaminer reliability of all aspects of the leg length analysis protocol used in this study.

Expression of the cytoskeleton linker protein ezrin in human cancers.

Expression of the metastasis-associated protein, ezrin, in over 5,000 human cancers and normal tissues was analyzed using tissue microarray immunohistochemistry. Ezrin staining was compared between cancers and their corresponding normal tissues, between cancers of epithelial and mesenchymal origin, in the context of the putative inhibitor protein, merlin, and against clinicopathological data available for breast, lung, prostate cancers and sarcomas. Ezrin was found in most cancers and normal tissues at varying levels of intensity. In general ezrin was expressed at higher levels in sarcomas than in carcinomas. By normalizing the expression of ezrin in each cancer using ezrin expression found in the corresponding normal tissue, significant associations between ezrin were found in advancing histological grade in sarcomas (P = 0.02) and poor outcome in breast cancer (P = 0.025). Clinicopathologic associations were not changed by simultaneous assessment of ezrin and merlin in each patient sample for the cancer types examined. These data support a role for ezrin in the biology of human cancers and the need for additional studies in breast cancer and sarcoma patients that may validate ezrin as a marker of cancer progression and as a potential target for cancer therapy.

Surgical management of complex proximal humerus fractures-a systematic review of 92 studies including 4500 patients.

OBJECTIVES: To compare the outcomes of open reduction and internal fixation (ORIF), closed reduction and percutaneous pinning, hemiarthroplasty (HA), and reverse shoulder arthroplasty (RSA) for proximal humerus fractures. DATA SOURCES: The search was performed on September 9, 2012 using an explicit search algorithm in the following databases: Medline, SportDiscus, CINAHL, and Cochrane Central Register of Controlled Trials. Inclusion criteria were English language studies reporting clinical outcomes after surgical treatment of 3- or 4-part proximal humerus fractures with a minimum of 1-year follow-up. STUDY SELECTION: English language studies reporting clinical outcomes after surgical treatment of 3- or 4-part proximal humerus fractures with a minimum of 1-year follow-up. Levels 1-4 studies were eligible for inclusion. DATA EXTRACTION: Study methodological quality and bias was evaluated using the Modified Coleman Methodology Score. DATA SYNTHESIS: Two-proportion Z test and multivariate linear regression analyses were used for group comparisons. CONCLUSIONS: Significantly better clinical outcomes were observed for ORIF over HA and RSA (American Shoulder and Elbow Score, Disabilities of Arm, Shoulder, and Hand, Constant) (P < 0.05). However, ORIF had a significantly higher reoperation rate versus HA and RSA (P < 0.001 for both). Comparing HA with RSA, there was no difference in any outcome measure. The rate of tuberosity nonunion was 15.4% in the HA group. There were more complications following closed reduction and percutaneous pinning versus ORIF, HA, and RSA (P < 0.05). ORIF for proximal humerus fractures demonstrates better clinical outcome scores but with a significantly higher reoperation rate. HA and RSA are effective as well, but tuberosity nonunion remains a concern with HA.

The effect of medial and lateral calcaneal osteotomies on the tarsal tunnel.

BACKGROUND: As an entrapment phenomenon, tarsal tunnel syndrome has been described after calcaneal osteotomy, and since the tibial nerve has also been shown to be very sensitive to ankle position, position of the calcaneus after osteotomy and displacement was thought to likely influence the environment of the tibial nerve within the tarsal canal. The respective volume of the tarsal canal was therefore hypothesized to decrease with medial or lateral displacement osteotomies of the calcaneus. METHODS: Anterior and posterior calcaneal osteotomies were made in cadaveric matched pairs and brought through sequential medial and lateral displacements. Magnetic resonance imaging was used to estimate the comparative resultant volume of the tarsal canal after each of these new positions were assumed, as compared with baseline. The proximity of the osteotomy cut to the nerve's location was also measured. RESULTS: The tarsal tunnel volume was calculated for all 5 displacement states and were as follows: far-lateral (9506 mm(3)), near-lateral (10 073 mm(3)), normal (11 839 mm(3)), near-medial (11 489 mm(3)), and far-medial (11 760 mm(3)). No significant difference in tarsal tunnel volume was identified between the normal, nondisplaced specimens in the anterior or posterior groups (11 954 mm(3) vs 11 809 mm(3)). No difference in tarsal tunnel volume was identified between the anterior and posterior osteotomies at any of the 4 displacements. The distance from tibial nerve to the medial exit site of the osteotomy was found to be significantly less in the anterior group compared to the posterior group (4 mm vs 14.2 mm, P < .0001). CONCLUSION: Lateral, but not medial, osteotomy fragment displacement results in significant reduction of tarsal tunnel volume. The location of the cut does not seem to affect any substantive change in volume. Anteriorly placed osteotomies appear to jeopardize the neurovascular structures more than posteriorly placed osteotomies. CLINICAL RELEVANCE: These findings provide surgeons with clinical evidence in support of performing a prophylactic tarsal tunnel release for patients undergoing lateralizing calcaneal osteotomies.

Salvage of contaminated osteochondral allografts: the effects of chlorhexidine on human articular chondrocyte viability.

BACKGROUND: Because chondrocyte viability is imperative for successful osteochondral allograft transplantation, sterilization techniques must provide antimicrobial effects with minimal cartilage toxicity. Chlorhexidine gluconate (CHG) is an effective disinfectant; however, its use with human articular cartilage requires further investigation. PURPOSE: To determine the maximal chlorhexidine concentration that does not affect chondrocyte viability in allografts and to determine whether this concentration effectively sterilizes contaminated osteoarticular grafts. STUDY DESIGN: Controlled laboratory study. METHODS: Osteochondral plugs were subjected to pulse lavage with 1-L solutions of 0.002%, 0.01%, 0.05%, and 0.25% CHG and cultured for 0, 1, 2, and 7 days in media of 10% fetal bovine serum and antibiotics. Chondrocyte viability was determined via LIVE/DEAD Viability Assay. Plugs were contaminated with Staphylococcus aureus and randomized to 4 treatment groups. One group was not contaminated; the 3 others were contaminated and received no treatment, saline pulse lavage, or saline pulse lavage with 0.002% CHG. Serial dilutions were plated and colony-forming units assessed. RESULTS: The control group and the 0.002% CHG group showed similar cell viability, ranging from 67% ± 4% to 81% ± 22% (mean ± SD) at all time points. In the 0.01% CHG group, cell viability was reduced in comparison with control by 2-fold at day 2 and remained until day 7 (P < .01). The 0.05% and 0.25% CHG groups showed a 2-fold reduction in cell viability at day 1 (P < .01). At day 7, cell viability was reduced to 15% ± 18% (4-fold decrease) for the 0.05% CHG group and 10% ± 19% (6-fold decrease) for the 0.25% CHG group (P < .01). Contaminated grafts treated with 0.002% CHG demonstrated no colony-forming units. CONCLUSION: Pulse lavage with 0.002% CHG does not cause significant cell death within 7 days after exposure, while CHG at concentrations >0.002% significantly decreases chondrocyte viability within 1 to 2 days after exposure and should therefore not be used for disinfection of osteochondral allograft. Pulse lavage does not affect chondrocyte viability but cannot be used in isolation to sterilize contaminated fragments. Overall, 0.002% CHG was shown to effectively decontaminate osteoarticular fragments. CLINICAL RELEVANCE: This study offers a scientific protocol for sterilizing osteochondral fragments that does not adversely affect cartilage viability.

Subpectoral biceps tenodesis for failed type II SLAP repair.

Superior labrum anterior-posterior lesions are a common cause of shoulder pain. The diagnosis, classification, and indications for surgical intervention remain controversial, and mixed outcomes are associated with primary repair. Given the increasing prevalence of primary superior labrum anterior-posterior repairs in the United States, more surgeons will need to treat patients with poor primary results. A retrospective review of prospectively collected data was performed on patients who underwent subpectoral biceps tenodesis for failed type II superior labrum anterior-posterior repair by a single surgeon between January 2008 and December 2011. Primary outcome variables included pain via the visual analog scale, American Shoulder and Elbow Surgeons score, and Short Form 12 score. Secondary outcome variables included the Simple Shoulder Test and Single Assessment Numeric Evaluation scores. Demographic and intraoperative information was recorded for each patient. A paired t test statistical analysis was performed with a P value less than .05 considered statistically significant. A total of 11 patients met the inclusion criteria. Of these patients, 9 (82%) completed postoperative surveys at a mean 26-month follow-up. Mean visual analog scale scores improved from 4.1 to 2.5 (P=.03), Simple Shoulder Test scores from 5.4 to 9.3 (P=.005), American Shoulder and Elbow Surgeons scores from 54.5 to 78.0 (P=.002), and Single Assessment Numeric Evaluation scores from 42.5 to 70.4 (P=.001). Mean SF-12 (physical component) improved from 35.5 to 47.9 (P=.018). No failures or peri- or postoperative complications occurred. No patients required additional surgery. The findings suggest that subpectoral biceps tenodesis as a salvage for failed type II superior labrum anterior-posterior repair demonstrates improved results. Larger scale comparative studies are required to justify this technique.

Initial fixation strength of transosseous-equivalent suture bridge rotator cuff repair is comparable with transosseous repair.

BACKGROUND: The outcome of rotator cuff repair correlates with tendon healing. Early studies of arthroscopic rotator cuff repair demonstrate lower healing rates than traditional open techniques. Transosseous-equivalent repair techniques (suture bridge) were developed to improve the initial fixation strength. PURPOSE: To compare the initial in vitro tensile fixation strength of a transosseous-equivalent suture bridge (TOE-SB) rotator cuff repair construct to a traditional transosseous (TO) suture construct. STUDY DESIGN: Controlled laboratory study. METHODS: Identical simulated rotator cuff tears were created on 8 matched pairs of humeri. Each matched pair underwent repair with 4 sutures using either the TOE-SB or TO technique. Initial fixation strength was tested in a custom testing jig. Each shoulder underwent 1000 cycles each of low and then high load testing. Gap displacement was measured at anterior and posterior sites of the repair with digital video tracking of paired reflective markers and recorded at predetermined cycle intervals. RESULTS: There were no statistically significant differences in gap formation at the repair sites under low or high load conditions between TOE-SB and TO techniques. The mean maximal gap formation of the repairs during low load testing in the TOE-SB and TO constructs was 0.93 ± 0.88 mm and 0.55 ± 0.22 mm, respectively (P = .505). The mean maximal gap formation during high load testing in the TOE-SB and TO constructs was 2.04 ± 1.10 mm and 2.28 ± 1.62 mm, respectively (P = .517). The most significant increase in gap distance occurred at the transition from low load to high load in both constructs. Most of the incremental displacement occurred within the first 100 cycles for both high and low load testing (P < .001). CONCLUSION: The arthroscopic TOE-SB technique is comparable in initial fixation strength to the traditional TO simple suture repair technique. CLINICAL RELEVANCE: Arthroscopic techniques can achieve initial fixation strength comparable with traditional TO techniques performed without suture anchors.

Are dropped osteoarticular bone fragments safely reimplantable in vivo?

BACKGROUND: There are limited data detailing the appropriate management of nondisposable autologous osteoarticular fragments that have been contaminated by the operating room floor. The goal of the present study was to perform a comprehensive, three-phase investigation to establish an appropriate intraoperative algorithm for the management of the acutely contaminated, but nondisposable, autologous osteoarticular bone fragment. METHODS: Phase I of the study was performed to quantify the rate of contamination and microbial profile of human osteoarticular fragments that were dropped onto the operating room floor (n = 162). Phase II was performed to assess the feasibility and optimal means of decontaminating 340 similar fragments that underwent controlled contamination with bacteria that were identified in Phase I; decontamination was performed with use of cleansing agents that are routinely available in an operating room. Phase III was performed to assess the effect of each decontamination process on fragment chondrocyte viability through histologic evaluation. RESULTS: The contamination rate in Phase I was 70%. Coagulase-negative Staphylococcus was the most commonly cultured organism. In Phase II, varying exposure time to the chemical agents did not make a significant difference in decontamination rates. Mechanical scrubbing was superior to mechanical saline solution lavage (zero of fifty-six cultures compared with twenty of fifty-six cultures were positive for coagulase-negative Staphylococcus; p < 0.001). As a whole, bactericidal agents were found to be more effective decontaminating agents than normal saline solution. Povidone-iodine and 4% chlorhexidine gluconate were the most effective decontaminating agents, with none of the twenty-eight specimens that were decontaminated with each agent demonstrating positive growth on culture. Phase III demonstrated that the groups that were treated with normal saline solution and povidone-iodine retained the greatest number of live cells and the least number of dead cells. Mechanical scrubbing significantly decreased chondrocyte viability as compared with a normal saline solution wash (p < 0.05). CONCLUSIONS: The majority of osteochondral fragments that contact the operating room floor produce positive bacterial cultures. Five minutes of cleansing with a 10% povidone-iodine solution followed by a normal saline solution rinse appears to provide the optimal balance between effective decontamination and cellular toxicity for dropped autologous bone in the operative setting.