Failure of the linkage mechanism in a semi-constrained total elbow arthroplasty is a rare and unpredictable event: a review of seven cases.

PURPOSE: Linked component of total elbow arthroplasty (TEA) consisted of bushing and locking pins. Failure of linked components is a rare complication of TEA. This study aims to investigate the mechanism and consequence of failure of the linkage mechanism in TEA surgeries. METHODS: Between 2010 and 2021, five patients received revision operation due to linked component failure. Besides, two patients underwent primary operation at another institute were also analyzed due to failure of the linkage mechanism. RESULTS: All seven patients underwent primary TEA and mean age for primary TEA was 48 (range, 27-62). Two patients had TEA for post-traumatic arthritis, three patients for rheumatoid arthritis, and two patients for comminuted distal humerus fracture. The average time between primary TEA and revision TEA for linked component failure was 13.6 years. Three bushing wear and four locking pin dissociation were diagnosed according to pre-operative radiography. Elbow pain and swelling are the most common clinical symptoms. Severe osteolysis, periprosthetic fracture, and stem loosening were noted in three bushing wear cases. In four dissociation of locking pin cases, breakage of male locking pin phalanges was demonstrated in two patients. For revision procedures, both the locking pins and bushings were replaced. No patients in the study required additional surgery after the revision operation for linked component failure. CONCLUSION: Osteolysis, component loosening, periprosthetic fracture may be expected after linked component failure. Patients should be regularly followed up from short-term to long-term with radiography. Early diagnosis and intervention with linked component exchange can prevent extensive revision surgery.

Two- Versus 8-Zone Lung Ultrasound in Heart Failure: Analysis of a Large Data Set Using a Deep Learning Algorithm.

OBJECTIVE: Scanning protocols for lung ultrasound often include 8 or more lung zones, which may limit real-world clinical use. We sought to compare a 2-zone, anterior-superior thoracic ultrasound protocol for B-line artifact detection with an 8-zone approach in patients with known or suspected heart failure using a deep learning (DL) algorithm. METHODS: Adult patients with suspected heart failure and B-lines on initial lung ultrasound were enrolled in a prospective observational study. Subjects received daily ultrasounds with a hand-held ultrasound system using an 8-zone protocol (right and left anterior/lateral and superior/inferior). A previously published deep learning algorithm that rates severity of B-lines on a 0-4 scale was adapted for use on hand-held ultrasound full video loops. Average severities for 8 and 2 zones were calculated utilizing DL ratings. Bland-Altman plot analyses were used to assess agreement and identify bias between 2- and 8-zone scores for both primary (all patients, 5728 videos, 205 subjects) and subgroup (confirmed diagnosis of heart failure or pulmonary edema, 4464 videos, 147 subjects) analyses. RESULTS: Bland-Altman plot analyses revealed excellent agreement for both primary and subgroup analyses. The absolute difference on the 4-point scale between 8- and 2-zone average scores was not significant for the primary dataset (0.03; 95% CI -0.01 to 0.07) or the subgroup (0.01; 95% CI -0.04 to 0.06). CONCLUSION: Utilization of a 2-zone, anterior-superior thoracic ultrasound protocol provided similar severity information to an 8-zone approach for a dataset of subjects with known or suspected heart failure.

Comparison of suture-bridge and independent double-row techniques for medium to massive posterosuperior cuff tears: a two-year retrospective study.

BACKGROUND: Transosseous-equivalent suture-bridge (TOE-SB) and independent double-row (IDR) repair techniques were developed to treat rotator cuff tears. The study was designed to prove that both TOE-SB and IDR techniques provided comparable clinical results and retear rate for medium to massive posterosuperior rotator cuff tears, while the surgical time and number of suture anchor used were less in the IDR group. STUDY DESIGN: Level of evidence: level III, Retrospective comparative study. METHODS: Patients with medium to massive posterosuperior rotator cuff tears receiving arthroscopic TOE-SB and IDR between November 2016 to October 2019 were retrospectively enrolled. All patients were confirmed to have grade ≤ 2 fatty infiltration in the muscles of the torn tendons. Revision, concomitant subscapularis tear, acromiohumeral distance < 7 mm, glenohumeral osteoarthritis, partial repair, incomplete repair, partial thickness, or irreparable posterosuperior cuff tear were excluded. Surgical time, number of suture anchor used for the surgery, pre-operative, and post-operative clinical scores such as Constant-Murley score, subjective shoulder value (SSV), and visual analog scale (VAS) were compared. The retear rates between groups were evaluated by ultrasound. RESULTS: Thirty-five IDR and thirty-five TOE-SB repairs were enrolled. The IDR technique required much fewer anchors than TOE-SB did to complete the cuff repair. The mean operation time in IDR and TOE-SB group were 86(18.23), and 114(18.7) (min), respectively (P <  0.01). The mean number of anchors used to complete the cuff repair was 2(0.17) in IDR and 3(0.61) in TOE-SB (P <  0.01). The Constant-Murley score improved from 34.9 ± 6.6 to 80.6 ± 9.4 in the IDR group, and 37.4 ± 6 to 81.9 ± 4.6 in the TOE-SB group (both P <  0.001). SSV improved from 24.6 ± 9.6 to 79.3 ± 10.6 in the IDR, and 27.9 ± 9 to 82.9 ± 6.9 in the TOE-SB group (both P <  0.001). VAS improved from 7.9 ± 0.6 to 1.5 ± 0.7 in the IDR, and 8 ± 0.5 to 1.3 ± 0.6 in the TOE-SB group (both P <  0.001) at final follow-up. No significant difference was found between the retear rates (14.3% in the IDR vs. 17.1% in the TOE-SB, respectively) in the 2-year follow-up. CONCLUSIONS: Both IDR and TOE-SB group provided comparable clinical results and retear rates for medium to massive posterosuperior rotator cuff tears. The surgical time and number of anchors used were less in the IDR group than in the TOE-SB group.

Early versus delayed mobilization for arthroscopic rotator cuff repair (small to large sized tear): a meta-analysis of randomized controlled trials.

BACKGROUND: The timing to start passive or active range of motion (ROM) after arthroscopic rotator cuff repair remains unclear. This systematic review and meta-analysis evaluated early versus delayed passive and active ROM protocols following arthroscopic rotator cuff repair. The aim of this study is to systematically review the literature on the outcomes of early active/passive versus delayed active/passive postoperative arthroscopic rotator cuff repair rehabilitation protocols. METHODS: A systematic review and meta-analysis of randomized controlled trials (RCTs) published up to April 2022 comparing early motion (EM) versus delayed motion (DM) rehabilitation protocols after arthroscopic rotator cuff repair for partial and full-thickness tear was conducted. The primary outcome was range of motion (anterior flexion, external rotation, internal rotation, abduction) and the secondary outcomes were Constant-Murley score (CMS), Simple Shoulder Test Score (SST score) and Visual Analogue Scale (VAS). RESULTS: Thirteen RCTs with 1,082 patients were included in this study (7 RCTs for early passive motion (EPM) vs. delayed passive motion (DPM) and 7 RCTs for early active motion (EAM) vs. delayed active motion (DAM). Anterior flexion (1.40, 95% confidence interval (CI), 0.55-2.25) and abduction (2.73, 95%CI, 0.74-4.71) were higher in the EPM group compared to DPM. Similarly, EAM showed superiority in anterior flexion (1.57, 95%CI, 0.62-2.52) and external rotation (1.59, 95%CI, 0.36-2.82), compared to DAM. There was no difference between EPM and DPM for external rotation, retear rate, CMS and SST scores. There was no difference between EAM and DAM for retear rate, abduction, CMS and VAS. CONCLUSION: EAM and EPM were both associated with superior ROM compared to the DAM and DPM protocols. EAM and EPM were both safe and beneficial to improve ROM after arthroscopic surgery for the patients with small to large sized tears.

Sessile Trichomes Play Major Roles in Prey Digestion and Absorption, While Stalked Trichomes Function in Prey Predation in Byblis guehoi.

Carnivorous plants in the genus Byblis obtain nutrients by secreting viscous glue drops and enzymes that trap and digest small organisms. Here, we used B. guehoi to test the long-held theory that different trichomes play different roles in carnivorous plants. In the leaves of B. guehoi, we observed a 1:2.5:14 ratio of long-stalked, short-stalked, and sessile trichomes. We demonstrated that the stalked trichomes play major roles in the production of glue droplets, while the sessile trichomes secrete digestive enzymes, namely proteases and phosphatases. In addition to absorbing digested small molecules via channels/transporters, several carnivorous plants employ a more efficient system: endocytosis of large protein molecules. By feeding B. guehoi fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA) to monitor protein transport, we found that sessile trichomes exhibited more endocytosis than long- and short-stalked trichomes. The uptaken FITC-BSA was delivered to the neighboring short epidermal cells in the same row as the sessile trichomes, then to the underlying mesophyll cells; however, no signals were detected in the parallel rows of long epidermis cells. The FITC control could be taken up by sessile trichomes but not transported out. Our study shows that B. guehoi has developed a well-organized system to maximize its food supply, consisting of stalked trichomes for prey predation and sessile trichomes for prey digestion. Moreover, the finding that sessile trichomes transfer large, endocytosed protein molecules to the underlying mesophyll, and putatively to the vascular tissues, but not laterally to the terminally differentiated epidermis, indicates that the nutrient transport system has evolved to maximize efficiency.

Outcomes of Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction According to GNRB Arthrometer Measurement.

Background and Objectives: To investigate the prognosis of combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction, we used a GNRB (Genourob, Laval, France) arthrometer to measure surgical outcomes. Materials and Methods: This retrospective study reviewed patients who underwent combined ACL and ALL reconstruction and had a minimum follow-up of 2 years. Subjective outcomes, namely the International Knee Documentation Committee (IKDC) evaluation form scale scores and Lysholm scores, were evaluated preoperatively and postoperatively. We used a GNRB arthrometer to test the side-to-side laxity under pressures of 134 and 200 N, and we calculated the differential of the slope of the curves. We also recorded complications. Results: Our study examined 18 patients (mean age: 30.56 ± 8.9 years, range: 19-53) with a mean follow-up of 27.37 ± 3.4 months (range: 24-36). Both Lysholm and IKDC scores were significantly improved following the operation. The GNRB arthrometer measured mean anteroposterior laxity side-to-side as 0.76 ± 0.78 mm and 0.82 ± 0.8 mm under pressures of 134 and 200 N, respectively. The mean side-to-side differential slope under 200 N was 3.52 ± 2.17 µm/N. These values indicated that patients displayed no graft tear or low functional knee instability. All patients had a grade 3 pivot shift preoperatively; only two patients had a grade 1 pivot shift postoperatively, with the rest having a negative pivot shift. Conclusions: Our study revealed that combined ACL and ALL reconstruction has an excellent prognosis. GNRB measurement demonstrated excellent stability, and most patients had no residual pivot shift.

Using Single Peroneal Longus Tendon Graft for Segmental Meniscus Transplantation and Revision Anterior Cruciate Ligament Combined Anterolateral Reconstruction.

This case report describes a new approach to segmental meniscal reconstruction using a peroneal longus autograft in a patient with recurrent traumatic medial meniscus tear and anterior cruciate ligament reconstruction (ACLR) failure. While allograft meniscal transplantation is the preferred method for treating meniscal deficiency, its high cost and various legal regulations have limited its widespread use. Autologous tendon grafts have been proposed as a substitute for allograft meniscus transplantation, but their initial results were poor, leading to little progress in this area. However, recent animal experiments and clinical studies have demonstrated promising results in using autologous tendon grafts for meniscal transplantation, including improvements in pain and quality of life for patients. Further research is needed to evaluate the effectiveness of segmental meniscal reconstruction using autologous tendon grafts, but it could potentially lead to more accessible and cost-effective treatment options for patients with meniscal deficiency.

Neuronal survival factor VGF promotes chemoresistance and predicts poor prognosis in lung cancers with neuroendocrine feature.

High-grade neuroendocrine tumors (NETs) of the lung consist of small-cell lung cancer (SCLC) and large-cell neuroendocrine carcinoma (LCNEC). Both exhibit aggressive malignancy with poor prognosis. The transformation of lung adenocarcinoma (ADC) to SCLC or LCNEC also contributes to acquired resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs). Despite initially being responsive to chemotherapy, high-grade NET patients inevitably develop drug resistance; thus, novel therapeutic targets are urgently needed for these patients. Our study reported that VGF (nerve growth factor inducible), a factor mainly expressed in neurons during neural development, is highly expressed in SCLC and LCNEC as well as in a subset of ADCs, whereas targeting VGF attenuates cancer cell growth and tumor formation. High VGF expression was associated with advanced stage SCLC and predicted poor prognosis in lung ADC. In addition, EGFR-TKI selection enriched VGF expression in TKI-resistant ADC under epigenetic control. The VGF locus possessed the HDAC1 binding site, and treatment of ADC cells with the HDAC1 inhibitor induced VGF expression. High VGF expression was associated with chemoresistance, and silencing VGF induced BMF and BCL2L11 expression and rendered lung cancer cells sensitive to chemotherapy drugs. These findings suggested the potential of VGF as a prognostic factor and therapeutic target in lung cancers with neuroendocrine feature.

Interobserver Agreement and Correlation of an Automated Algorithm for B-Line Identification and Quantification With Expert Sonologist Review in a Handheld Ultrasound Device.

OBJECTIVES: B-lines are ultrasound artifacts that can be used to detect a variety of pathologic lung conditions. Computer-aided methods to detect and quantify B-lines may standardize quantification and improve diagnosis by novice users. We sought to test the performance of an automated algorithm for the detection and quantification of B-lines in a handheld ultrasound device (HHUD). METHODS: Ultrasound images were prospectively collected on adult emergency department patients with dyspnea. Images from the first 124 patients were used for algorithm development. Clips from 80 unique subjects for testing were randomly selected in a predefined proportion of B-lines (0 B-lines, 1-2 B-lines, 3 or more B-lines) and blindly reviewed by five experts using both a manual and reviewer-adjusted process. Intraclass correlation coefficient (ICC) and weighted kappa were used to measure agreement, while an a priori threshold of an ICC (3,k) of 0.75 and precision of 0.3 were used to define adequate performance. RESULTS: ICC between the algorithm and manual count was 0.84 (95% confidence interval [CI] 0.75-0.90), with a precision of 0.15. ICC between the reviewer-adjusted count and the algorithm count was 0.94 (95% CI 0.90-0.96), and the ICC between the manual and reviewer-adjusted counts was 0.94 (95% CI 0.90-0.96). Weighted kappa was 0.72 (95% CI 0.49-0.95), 0.88 (95% CI 0.74-1), and 0.85 (95% CI 0.89-0.96), respectively. CONCLUSIONS: This study demonstrates a high correlation between point-of-care ultrasound experts and an automated algorithm to identify and quantify B-lines using an HHUD. Future research may incorporate this HHUD in clinical studies in multiple settings and users of varying experience levels.

Clinical and functional outcomes of isolated posterior cruciate ligament reconstruction in patients over the age of 40 years.

BACKGROUND: To assess clinical and functional outcomes of patients aged 40 years or older receiving PCL reconstruction surgery. METHODS: All patients older than 40 years with isolated PCL rupture who underwent PCL reconstruction surgery were enrolled into the retrospective study. Associated meniscal injuries, osteochondral lesions, postoperative complications, and the rate of return to the preinjury level of activity were extracted. Outcomes included International Knee Documentation Committee (IKDC) subjective score, Lysholm score, and Tegner activity score. The minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were used to evaluate the clinically relevant value of PCL reconstruction in this population. RESULTS: In total, 41 patients with a mean age of 51.7 years were included. The mean follow-up time was 32.8 months. Associated lesions included meniscal injuries (48.8%) and osteochondral lesions (97.6%). Improvement in the IKDC score (from 46.5 preoperatively to 79.0 postoperatively, p < 0.0001), Lysholm score (from 65.5 to 88.3, p < 0.0001), and Tegner activity score (from 2.3 to 4.0, p < 0.0001) was recorded. The clinically relevant value based on the MCID showed that 34 of 41 patients (82.9%) had a ΔIKDC score exceeding 16.8; all patients (100%) showed a ΔLysholm score exceeding 8.9; and 35 of 41 patients (85.4%) showed a ΔTegner activity score exceeding 0.5. Regarding the PASS, none of the patients had an IKDC score exceeding 75.9 preoperatively, whereas 27 of 41 patients (65.9%) had a score of more than 75.9 postoperatively. All patient had ≥ grade II knee instability preoperatively. Postoperatively, 36 patients (87.8%) had no significant joint translation, and 5 patients (12.2%) had grade I instability. Twenty-one patients (51.2%) returned to their preinjury level of activity. Five patients (12.2%) developed Ahlbäck grade I radiographic osteoarthritis. No rerupture or other major perioperative complications were reported. CONCLUSIONS: PCL reconstruction is a reliable surgery for middle-aged patients suffering from persistent instability even after failed conservative treatment, with significant improvement in patient-reported outcomes that exceeded MCID in the majority of patients, restoration of subjective instability, and approximately half of the patients returned to preinjury activity levels. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Functional Outcomes Are Similar After Arthroscopic Capsular Repair of Triangular Fibrocartilage Complex Tears Between Outside-In Technique and All-Inside Technique Using Pre-Tied Suture Device.

PURPOSE: To compare outcomes of arthroscopic triangular fibrocartilage complex capsular repair at 2-year follow-up between outside-in and all-inside techniques. METHODS: In total, 58 consecutive patients (wrists) with a Palmer 1B triangular fibrocartilage complex tear without symptomatic distal radioulnar joint instability underwent arthroscopic suture repair from 2011 to 2019 including 31 patients via the outside-in technique (group A) and 27 via the all-inside technique using a pre-tied needle device (group B). Two-year follow-up included visual analog scale (VAS) pain score, motion range, grip strength, Mayo Modified Wrist Score (MMWS), the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score, and complication rate. Correlation between functional result and patient satisfaction was analyzed. RESULTS: Score changes in VAS, wrist flexion-tension, supination-pronation, grip strength, MMWS, and QuickDASH at 2-year follow-up were not significantly different between group A (3.4 ± 0.8, 18.4 ± 17.5, 12.9 ± 13.3, 30.7 ± 11.2, 26.6 ± 7.9 and 19.4 ± 9.9 and group B (3.4 ± 1.0, 18.5 ± 18.3, 15.6 ± 13.7, 30.8 ± 11.4, 28.1 ± 8.6, and 7.6 ± 7.2) with P values of .400, .489, .223, .486, .240, and .223 respectively. Surgical time averaged 105 minutes (78 to 136) in group A and 94 minutes (61-126) in group B with significant difference (P = .012). Patient satisfaction averaged 1.1 (0-3.5) in group A and 1.0 (range 0-3.0) in group B. Satisfaction score was more strongly correlated with QuickDASH (coefficients: 0.863 in group A and 0.918 in group B) than with MMWS (-0.693 in group A and -0.465), grip strength (-0.619 in group A and -0.417 in group B) and VAS score (0.607 in group A and 0.222 in group B). CONCLUSIONS: Both techniques achieved comparable outcomes with shorter surgical time in all-inside repair using pre-tied needle device. Patient satisfaction was strongly correlated with QuickDASH score. LEVEL OF EVIDENCE: Level III, retrospective therapeutic comparative investigation.

Arthroscopic Pan-Capsular and Transverse Humeral Ligament Release with Biceps Tenodesis for Patients with Refractory Frozen Shoulder.

Arthroscopic capsular release allows direct visualization and release of inflamed tissues in refractory frozen shoulder. The reticular neural network in the long head of the biceps tendon (LHBT) and nerve endings of the transverse humeral ligament (THL) might be responsible for shoulder pain. We hypothesized that patients with painful refractory frozen shoulder benefited from pan-capsular release, THL release, and LHBT tenodesis. The LHBT tenodesis decreased the possibility of LHBT instability. The balance of the shoulder joint was maintained after such extensive release. From October 2013 to June 2019, patients with painful refractory frozen shoulder were enrolled consecutively at the same institute. All patients received arthroscopic pan-capsular, THL release, and suprapectoral LHBT tenodesis with a minimum of 2-year follow-up. Preoperative and postoperative shoulder range of motion (ROM), pain visual analog scale (PVAS), subjective shoulder value (SSV), constant score, LHBT score, acromio-humeral distance (AHD), and critical shoulder angle (CSA) were recorded. In total, 35 patients with an average age of 53.1 ± 9 years were enrolled. The average follow-up period was 24 ± 1.5 months. Forward elevation improved from 105.1° ± 17° to 147° ± 12° (p < 0.001), external rotation improved from 24.1° ± 13.3° to 50.9° ± 9.7° (p < 0.001), and internal rotation improved from L3 to T9 (p < 0.001), respectively, at final follow-up. PVAS improved from 7.3 ± 1.1 to 1.8 ± 0.6 (p < 0.001), constant score from 23.4 ± 11 to 80.7 ± 5.2 (p < 0.001), and SSV from 27.7 ± 10.5 to 77.4 ± 3.8, respectively, at follow-up. No differences were found in AHD and CSA after surgery (p = 0.316, and p = 0.895, respectively). Patients with painful refractory frozen shoulder benefited from pan-capsular and THL release. A radiographically balanced shoulder joint was maintained even after such extensive release.

Recurrent Shoulder Instability after Arthroscopic Bankart Repair in an Elite Baseball Pitcher-A Case Report.

A 16-year-old right-handed male pitcher had a first-time right anterior shoulder dislocation during a baseball game. X-ray and MRI revealed no apparent glenoid bone loss or Hill-Sachs lesion, but an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion with mild posterolateral decompression of the humerus head. His instability severity index score (ISIS score) was 5 with an on-track lesion. He had an arthroscopic Bankart repair using two all-suture anchors and returned to pitching 6 months after the index surgery. However, he had an unstable sensation after 50 pitches during a game one year postoperatively. This time, he presented with a significant Hill-Sachs lesion and a recurrent APLSA lesion. His ISIS score was 6 with an on-tract lesion. During the arthroscopic examination, the previous suture was stable, while anterior capsuloligament tissues were dislodged from sutures, and a Hill-Sachs lesion was observed. This time, a revision arthroscopic Bankart repair and Remplissage procedure were done on him with four double-loaded soft tissue anchors. Pitchers often develop more external rotation in their throwing arm because of a repetitive stretch of the anterior shoulder capsule and ligaments during pitching. The decrease in external rotation after surgery may limit the pitching speed of the pitcher, making a return to play (RTP) more difficult. There is still a paucity of best evidence to revise a failed arthroscopic Bankart repair in the dominant arm of a pitcher. Arthroscopic Bankart repair and Remplissage procedure have gained increasing popularity because they can provide a stable shoulder without harvesting the coracoid. The Latarjet procedure provides a high RTP rate; however, we did not perform it in the revision surgery and decided to revise the Bankart lesion again on its own with a Remplissage procedure, even with his ISIS score being 6 before the revision surgery. A salvage Latarjet procedure is left as a bailout procedure.

Pneumothorax, an Uncommon but Devastating Complication following Shoulder Arthroscopy: Case Reports.

Shoulder arthroscopy is a mature and widely used treatment to deal with various shoulder disorders. It enables faster recovery and decreases postoperative complications. However, some complications related to shoulder arthroscopy cannot be neglected because they could be life threatening. We presented three cases of various clinical manifestations of pneumothorax after shoulder arthroscopy. The first case was a 65-year-old female who underwent arthroscopic rotator cuff repair under general anesthesia and interscalene nerve block in the beach-chair position. The second case was a 58-year-old male undergoing arthroscopic rotator cuff repair and reduction in glenoid fracture under general anesthesia in the lateral decubitus position. The third case was a 62-year-old man receiving arthroscopic rotator cuff repair under general anesthesia in the lateral decubitus position. Each case's operation time was 90, 240, and 270 min. The pressure of the irrigation pumping system was 30, 50, and 70 mmHg, respectively. The second and third cases did not undergo interscalene nerve block. Although the incidence of pneumothorax following shoulder surgery and interscalene nerve block was only 0.2%, it is one of the most life-threatening complications following shoulder arthroscopy. In these cases, multifactorial factors, including patient positioning, interscalene nerve block, long surgical time, size of rotator cuff tears, and the pressure of the irrigation and suction system, can be attributed to the occurrence of pneumothorax. It is crucial to fully comprehend the diagnosis and management of pneumothorax to reduce the risk for patients receiving shoulder arthroscopy.

Retrospective cohort study on radial head arthroplasty comparing long-term outcomes between valgus type injury and fracture dislocation.

BACKGROUND: Radial head arthroplasty (RHA) has been commonly adopted for irreparable radial head fractures while little information is addressed on valgus type injury. The purpose of this study is to report long-term outcomes and radiographic analysis in RHA for valgus type injury with comparison to fracture dislocation injury. METHODS: A retrospective cohort study was conducted in patients receiving unilateral RHA with loose-fit, modular metal prosthesis for irreparable radial head fractures between 2004 and 2012. Totally, 33 patients with a mean follow up of 9 years (range, 7 to 15 years) were enrolled and divided into two groups including 14 valgus injuries and 19 fracture-dislocations. Demographics of the patients, injury details, clinical and radiographic outcomes, and correlation analysis were investigated and compared between two groups. RESULTS: In patient demographics, significant difference was noted in sex distribution (p = 0.001), lateral collateral ligament involvement (p = 0.000) and time from injury to RHA (p = 0.031) between two groups. No patient underwent subsequent removal or revision of prosthesis. Good to excellent results according to Mayo Elbow Performance Score (MEPS) was achieved in 13 and 14 patients in group A and B respectively. Final motion range and Disabilities of the Arm, Shoulder, and Hand score was significantly better in valgus injury group. Radiographic analysis demonstrated fewer patients in valgus injury group presented periprosthetic osteolysis with weak to moderate negative correlation between radiolucency score and MEPS. CONCLUSIONS: With an average of 9 years follow-up, RHA using loose-fit, modular metal prosthesis achieves encouraging outcomes for both valgus injury and fracture dislocation. In valgus type injury, better motion range, lower disability score and lower incidence of periprosthetic osteolysis is noted while correlation analysis of radiolucency score suggests extended, long-term investigation.

Clinical and Functional Outcomes of Anterior Cruciate Ligament Reconstruction With Autologous Hamstring Tendon in Patients Aged 50 Years or Older.

PURPOSE: To assess the clinical and functional outcomes, including the return to sports and the progression of arthritis, in patients aged 50 years or older after anterior cruciate ligament (ACL) reconstruction. METHODS: A retrospective series of patients aged 50 years or older with ACL rupture who received ACL reconstruction surgery with autologous hamstring tendon was examined. Preoperative and postoperative functional outcomes were evaluated with the International Knee Documentation Committee (IKDC) subjective score, Lysholm score, and Tegner activity score. Associated injuries, postoperative complications, and the rate of return to preinjury sports were documented. A paired t test and the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were used for statistical evaluation. RESULTS: A total of 67 patients with a mean age of 56.6 years were enrolled. The mean follow-up time was 30.2 months. Clinical improvement in the IKDC score (from 41.4 preoperatively to 88.9 postoperatively), Lysholm score (from 49.8 to 86.1), and Tegner activity score (from 2.7 to 4.4) was noted. Regarding clinically relevant values of the MCID, all patients (100%) showed a ΔLysholm score exceeding 8.9; 66 of 67 patients (98.5%) revealed a ΔIKDC score exceeding 16.7; and 47 of 67 patients (70.1%) showed a ΔTegner activity score of more than 1. For the PASS, none of the patients had an IKDC score over 75.9 preoperatively whereas 60 patients (89.5%) had a score exceeding 75.9 postoperatively. Associated lesions included meniscal injuries (73.1%) and osteochondral lesions (89.6%). Of the patients, 36 (53.7%) returned to preinjury sports and 18 (22.9%) returned to sports with less intensity. No major complication, rerupture, or deterioration of arthritis was noted. CONCLUSIONS: Patients aged 50 years or older receiving ACL reconstruction achieved significant improvements in IKDC, Lysholm, and Tegner scores. All patients reached the MCID for the ΔLysholm score; 98.5%, for the ΔIKDC score; and 70.1%, for the ΔTegner activity score. None of the patients reached the PASS for the preoperative IKDC value, whereas 89.5% reached the PASS postoperatively. Among patients aged 50 years or older, 53.7% returned to preinjury sports and 26.9% returned to sports with lower intensity. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Intramedullary nailing and plating osteosynthesis in the correction of post-traumatic deformity in late-diagnosed distal radius fractures: a retrospective comparison study.

BACKGROUND: Various surgical modalities are available for correction of deformity in late-diagnosed distal radius fractures. This study compared surgical outcomes between intramedullary nailing and plating osteosynthesis in open-wedge osteotomy. METHODS: We retrospectively reviewed 47 unilateral distal radius fractures that underwent open-wedge osteotomy at more than 4 weeks after injury between 2006 and 2011. A locally resected exuberant callus was used as the bone graft. Two types of fixation were used: intramedullary nail in 22 patients (group A) and locking plate in 25 patients (group B). Radiographic analysis including radial height, radial inclination, and volar tilt were performed preoperatively and 2-year postoperatively. The Modified Mayo Wrist Score (MMWS) was used for functional evaluation and a 10-point visual analog scale (VAS) for residual pain assessment. Patient satisfaction was self-reported as a 5-point scale. Radiographic data, functional outcomes, and surgical complications were compared between the two groups. RESULTS: All fractures achieved bone union without major complications. The MMWS averaged 84.8 ± 9.7 in group A and 85.2 ± 8.4 in group B, without significant differences (p = 0.436). Instead, significant differences were found in mean wrist flexion (73.6 ± 7.9 vs. 69.6 ± 7.8 degrees; p = 0.042), patient satisfaction (3.6 ± 1.1 vs. 2.9 ± 1.2; p = 0.034), postoperative radial height (11.6 ± 2.6 vs. 10.2 ± 3 mm; p = 0.039) and inclination (20.8 ± 2.8 vs. 17.7 ± 4.1 degrees; p = 0.004), and implant-related complications (9% vs. 36%; p = 0.03). There were no significant differences in other assessment items including postoperative grip strength, pain scale, supination/pronation/extension, volar tilt, correction angles of all three parameters, and general complication rate. Four patients in group A (18%) and 2 in group B (8%) experienced postoperative paresthesia of the surgical hand; no significant difference was noted. All except one patient in group B had full recovery of neurological symptoms. CONCLUSIONS: Open-wedge osteotomy with either an intramedullary nail or locking plate fixation yielded encouraging radiographic and functional outcomes. Intramedullary nail fixation may facilitate restoration of radial height and inclination with better wrist flexion, less implant-related complications, and greater patient satisfaction.

Real-time detection of antibiotics cytotoxicity in rabbit periosteal cells using microfluidic devices with comparison to conventional culture assays.

BACKGROUND: Local antibiotic application has been widely used in orthopedic surgery. The dose-related toxicity of antibiotics towards periosteal tissues and resulting effects on osteogenic expression are yet to be studied. METHODS: Periosteal cells harvested from the medial tibia of New Zealand White rabbits were used. A seeding density of 5 × 103 cells/cm2 was determined to be optimal for testing in the pilot study; the cells were cultured in xCELLigence 96-well plates. Microfluidic impedance analyzers were used to monitor cellular proliferation in microfluidic culture systems with exposure to three different concentrations (10 µg/mL, 100 µg/mL, and 1000 µg/mL) of cefazolin, ciprofloxacin, and vancomycin, respectively. The correlation of cell index at day 7 with optical density values from WST-1 assays using conventional cultures was evaluated by calculating the Pearson's coefficient. RNA analysis was performed to investigate the expression of osteogenic markers in the cultured cells, including core-binding factor alpha 1 (Cbfa1), osteopontin (OPN), and osteopontin promoter (OPNp), relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as the endogenous control. RESULTS: A significant dose-related inhibition of cell index was found for all the 3 antibiotics, whereas the WST-1 assays showed a significant dose-related inhibition of cellular proliferation only at a high dose of cefazolin (1000 µg/mL) and medium-to-high dose of ciprofloxacin (100 µg/mL and 1000 µg/mL). Pearson's coefficient analysis indicated a high correlation between the cell index and optical density values of WST-1 assays only for medium and high doses of ciprofloxacin (100 µg/mL and 1000 µg/mL); a moderate correlation was seen for cefazolin, and a low dose of ciprofloxacin (10 µg/mL). RNA analysis confirmed significant dose-related inhibition of cfba1, OPN, and OPNp expression by all three antibiotics. CONCLUSION: With optimal seeding amounts, rabbit periosteal cells can be dynamically monitored in the xCELLigence microfluidic system. Dose-related inhibition of cellular proliferation and osteogenic expression was found after exposure to cefazolin and ciprofloxacin. By providing real-time detection and exhibiting comparable correlation, microfluidic impedance-based analyzer is a feasible alternative to the conventional WST-1 assays.

Anteromedial fractures of the ulnar coronoid process: correlation between surgical outcomes and radiographic findings.

BACKGROUND: This study aimed to report the radiographic findings and surgical outcomes of anteromedial facet (AMF) fracture of the ulnar coronoid process and to suggest an optimal approach. METHODS: In this retrospective study, 20 consecutive patients with unilateral AMF fracture of coronoid process were surgically treated and divided into two groups without (group A) and with (group B) additional proximal ulnar fractures in equal case number. Time from injury to surgery averaged 4.38 ± 2.56 weeks. Mayo Elbow Performance Score (MEPS) and Shortened Disability of the Arm and Shoulder and Hand (quickDASH) score were used for functional evaluation. Cohen kappa coefficient (kappa) analysis was used to determine interobserver reliability on a radiographic reading. RESULTS: All cases had a mean follow-up of 2.3 years. MEPS at 2 years averaged 87.75 ± 12.51; quickDASH, 7.05 ± 6.19. A significantly higher MEPS was found in subtype 3 than in subtype 2 (p = 0.036) and in group B than in group A (p = 0.020). Significantly lower quickDASH cores were found in group B than in group A (p = 0.011). Kappa analysis showed moderate agreement in the O'Driscoll classification (kappa = 0.56) and substantial agreement in categorization of the additional proximal ulnar fractures (kappa = 0.76). CONCLUSIONS: Additional proximal ulnar lesions were considered an integral part of varus posteromedial rotatory instability and required further categorization in the management of AMF fractures. Significantly better functional outcomes were achieved when those lesions were fully addressed.

Investigation of osteogenic activity of primary rabbit periosteal cells stimulated by multi-axial tensile strain.

Periosteum-derived cells was indicated to respond to mechanical force and have stem cell potential capable of differentiating into multiple tissue. Investigation of osteogenic activity under mechanical stimulation is important to understand the therapeutic conditions of fracture healing. In this work, a cell culture platform was developed for respectively providing isotropic and anisotropic axial strain. Primary rabbit periosteal cells were isolated and cultured in the chamber. Multi-axial tensile strain was received and osteogenic activity was investigated by mRNA expressions of CBFA1 and OPN. The highest mRNA expression was found in moderate strain (5-8%) under anisotropic axial strain. These results provided important foundation for further in vivo studies and development of tailor-made stretching rehabilitation equipment.