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Biomedical subjects

Gerald R Williams

Publications and source records attributed to Gerald R Williams.

At least 19 recordsLinked to original sources
PubMed2006

Arthroscopic treatment of posterior glenohumeral joint subluxation resulting from brachial plexus birth palsy.

The purpose of this study is to assess the ability of arthroscopic anterior capsular release, subscapularis tenotomy, and glenohumeral manipulation to reduce glenohumeral joint subluxation resulting from brachial plexus birth palsy. Twenty-two children with a mean age of 3.9 years (range, 1.6-8.3 years) underwent preoperative magnetic resonance imaging, arthroscopic surgery with or without tendon transfers, and postoperative imaging in their spica cast. In the uninvolved shoulders, the mean percentage of the humeral head anterior to the middle of the glenoid fossa (PHHA) was 45.2% +/- 4.8% and the mean glenoid version was -7% +/- 3%. In the involved shoulders, preoperatively, the mean PHHA was 15.6% +/- 13.5% and the mean glenoid version was -37 degrees +/- 15 degrees . Postoperatively, the mean PHHA corrected to 46.9% +/- 11.2% and the mean glenoid version improved to -8 degrees +/- 8 degrees . There was a significant improvement in the mean PHHA (P < .001) and mean glenoid version (P < .001) that approached the values of the uninvolved shoulder. Arthroscopic capsular release and subscapularis tenotomy were successful in obtaining reduction of glenohumeral joint subluxation in all patients. The maintenance of reduction requires continued follow-up over time.

Arthroscopy↗
PubMed2006

The role of repair tension on tendon to bone healing in an animal model of chronic rotator cuff tears.

Rotator cuff tendon tears are one of the most common shoulder injuries. Although surgical repair is typically beneficial, re-tearing of the tendons frequently occurs. It is generally accepted that healing is worse for chronic tears than acute tears, but the reasons for this are unknown. One potential cause may be the large tensions that are sometimes required to repair chronically torn tendons back to bone (i.e., repair tension). Therefore, the objective of this study was to utilize an animal model of chronic rotator cuff repairs to investigate the role of increased repair tension on tendon to bone healing. We hypothesized that an increase in repair tension would be related to detrimental changes to the healing insertion site. To test this hypothesis, the supraspinatus tendon of rats was surgically detached and then repaired immediately or after a delay of 2, 4, or 16 weeks. The repair tension was measured using a tensiometer and the mechanical properties, collagen organization, and protein expression of the healing insertion site were evaluated 4 and/or 16 weeks following repair. We found that the repair tension increased with time following detachment, and was related to a decrease in the failure properties and viscoelastic peak stress and an increase in cross-sectional area and stiffness of the insertion site. Therefore, repair tension should be minimized in the clinical setting. Future studies will include additional animal model studies involving the relationship between tension and muscle properties and a clinical study investigating the role of repair tension on repair failure.

Animals↗
PubMed2006

Loss of passive external rotation at 90 degrees abduction is predictive of a medially healed Bankart lesion.

PURPOSE: This prospective study correlates passive range of external rotation with arthroscopic findings in patients with anterior instability for the purpose of defining criteria that can be used to detect a medially healed Bankart lesion. METHODS: External rotation at 90 degrees abduction (ER90) was assessed on examination with the patient under anesthesia in bilateral shoulders of 46 consecutive patients with unidirectional, anterior glenohumeral instability. Arthroscopy was used to identify 22 patients with a detached Bankart lesion (group I) and 24 patients with a medially healed Bankart lesion (group II). Differences in ER90 between symptomatic and asymptomatic shoulders for both groups were compared. The t test and the Wilcoxon rank-sum test measured significance. RESULTS: In group I, mean ER90 in the symptomatic shoulder was 5 degrees greater than in the asymptomatic shoulder; in group II, mean ER90 in the symptomatic shoulder was 7.4 degrees less than in the asymptomatic shoulder (P < .001). Loss of ER90 was highly sensitive (92%) and specific (95%), with a positive predictive value of 96% for detection of a medially healed Bankart lesion. CONCLUSIONS: If a loss of 5 degrees or more of ER90 in the affected shoulder is found on examination under anesthesia, one should have a high degree of suspicion for the presence of a medially healed Bankart lesion. LEVEL OF EVIDENCE: Level II, development of diagnostic criteria on basis of consecutive patients.

Adolescent↗
PubMed2006

Evaluation and management of valgus impacted four-part proximal humerus fractures.

UNLABELLED: A valgus impacted, four-part humerus fracture is an uncommon but important injury to recognize in patients with orthopaedic trauma. Recognizing this fracture pattern and understanding the pathoanatomy of it are essential to providing appropriate care. The treatment options for valgus impacted, four-part humerus fractures range from nonoperative care to hemiarthroplasty. The peer-reviewed literature provides insight into the important factors to consider in deciding how to treat patients with valgus impacted, four-part humerus fractures. Recently, less invasive surgical techniques have been reported as a way to preserve the blood supply to the articular fracture fragment, which decreases the risk of developing avascular necrosis. Even though these techniques are becoming more popular, they are not indicated for all patients. Surgeons must use an individualized approach for each patient with this fracture. Satisfactory results have been reported for the nonoperative and operative techniques used to treat valgus impacted, four-part humerus fractures. However, less invasive procedures may help to achieve a more favorable clinical outcome. Limiting the surgical approach and achieving stabilization with minimal fixation helps to preserve the viability of the humeral head and to prevent postoperative morbidity related to osseous and soft tissue healing. Hemiarthroplasty becomes a reasonable treatment option in older patients with substantial displacement of the fracture fragments and poor bone quality that would not support internal fixation. LEVEL OF EVIDENCE: Therapeutic study, level V (expert opinion). See Guidelines for Authors for a complete description of levels of evidence.

Arthroplasty↗
PubMed2006

Arthroscopy effectively treats ganglion cysts of the shoulder.

UNLABELLED: In the hands of an experienced arthroscopist, arthroscopic decompression of a spinoglenoid notch cyst can lead to resolution of a patient's symptoms and complete functional recovery. In our study, we hypothesized that patients with a spinoglenoid notch cyst who were treated arthroscopically would have return to near normal function of their shoulders and that the outcomes for patients with a spinoglenoid notch cyst and associated labral tears would be no different than the outcomes for patients with a spinoglenoid notch cyst without associated labral tears. We retrospectively evaluated 18 consecutive patients who were treated arthroscopically for a spinoglenoid notch cyst. Nine had isolated arthroscopic decompression, and nine arthroscopic decompression with a labral repair. We used the validated American Shoulder and Elbow Society (ASES) and University of Pennsylvania (Penn) shoulder scores to evaluate patients' outcomes. We found improvements in the postoperative ASES and Penn shoulder scores for all outcomes measured including pain, satisfaction, and function. However, there were no differences in outcome when comparing the group that had decompression with the group that had decompression and labral repair for an associated superior labral anterior posterior tear. LEVEL OF EVIDENCE: Therapeutic study, Level III (retrospective cohort study). See the Guidelines for Authors for a complete description of levels of evidence.

Adolescent↗
PubMed2006

Arthroscopic and open Bankart repairs provide similar outcomes.

UNLABELLED: Recurrent instability after arthroscopic Bankart repair has decreased, largely because of improvements in surgical technique. We wanted to know whether there were differences in functional outcomes (using a validated outcomes measure) in patients who had arthroscopic Bankart repair or open Bankart repair for recurrent anterior glenohumeral instability. We retrospectively reviewed 106 patients who had a Bankart repair for recurrent anterior glenohumeral instability from 1998-2001. Of the 93 patients included, 69 patients had arthroscopic Bankart repair and 24 patients had open Bankart repair. The indications for surgery in the two groups were similar. The average age of the patients was 29.9 years (arthroscopic Bankart repair, 31 years; open Bankart repair, 28 years). The followup ranged from 24-77 months. The average modified American Shoulder and Elbow Surgeons score (PENN score) for pain, satisfaction, and function were 26.3, 8.5, and 55.1, respectively, in the arthroscopic Bankart repair group and 26.6, 8.8, and 54.2, respectively, in the open Bankart repair group. The total score was 90 in the arthroscopic Bankart repair group and 89.5 in the open Bankart repair group. Recurrent instability occurred in one patient in each group. We found no difference in outcomes between the arthroscopic and open Bankart repair groups using patient-assessed outcomes. LEVEL OF EVIDENCE: Therapeutic Study, Level III (retrospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.

Adolescent↗
PubMed2006

Latissimus dorsi tendon transfer for irreparable posterosuperior rotator cuff tears. Factors affecting outcome.

BACKGROUND: The purpose of this study was to evaluate the clinical results of latissimus dorsi tendon transfer in patients with an irreparable posterosuperior rotator cuff tear to help determine which patient and anatomic factors affect clinical outcome. METHODS: Fourteen patients with a latissimus dorsi tendon transfer were clinically evaluated with use of the PENN (University of Pennsylvania) shoulder score as well as with quantitative measurement of isometric muscle strength and the range of motion of both shoulders at a minimum of twenty-four months postoperatively. The anatomic results were evaluated with postoperative magnetic resonance imaging and electromyography. RESULTS: Nine patients were satisfied with the outcome, had significant clinical improvement, and reported that they would have the operation again under similar circumstances. The other five patients were dissatisfied with the result and had significantly worse PENN scores, active elevation, and objective measures of strength. Eight of the nine patients with a good clinical result were male, and four of the five with a poor result were female. Patients with a good clinical result had had significantly better preoperative function in active forward flexion and active external rotation compared with the patients with a poor result. The magnetic resonance imaging demonstrated healing of the tendon to the greater tuberosity in twelve patients and equivocal healing in two. There was no significant atrophy of any of the transferred muscles. Electromyography demonstrated clear activity in the transferred latissimus muscle during humeral adduction in all fourteen patients, some electrical activity with active forward elevation in only one patient, and some electrical activity with active external rotation in six of the nine patients with a good clinical result. None of the patients with a poor clinical result demonstrated electrical activity of the transferred muscle with active forward flexion or external rotation. CONCLUSIONS: Synchronous in-phase contraction of the transferred latissimus dorsi is a variable finding following the surgical treatment of irreparable posterosuperior rotator cuff tears, but when it is present it is associated with a better clinical result. Preoperative shoulder function and general strength influence the clinical result. Female patients with poor shoulder function and generalized muscle weakness prior to surgery have a greater likelihood of having a poor clinical result.

Adult↗
PubMed2006

The Penn shoulder score: reliability and validity.

STUDY DESIGN: Psychometric evaluation of a cross-sectional survey. OBJECTIVES: The purpose of this study was to examine the psychometric properties of reliability and validity of the Penn Shoulder Score (PSS). BACKGROUND: Shoulder outcome measures are used to assess patient self-report levels of pain, satisfaction, and function. The PSS is a 100-point shoulder-specific self-report questionnaire consisting of 3 subscales of pain, satisfaction, and function. This scale has been utilized in the literature. However, the measurement properties of reliability and validity, including responsiveness, of the PSS subscales and overall scale need to be established. METHODS AND MEASURES: Patients (n = 40) with shoulder disorders undergoing a course of outpatient physical therapy completed the PSS at initial visit and again within 72 hours to assess test-retest reliability. The Constant Shoulder Score (CSS) and the American Shoulder and Elbow Surgeons Shoulder Score (ASES) were also completed at the initial visit and compared to the PSS to assess convergent construct validity. A separate cohort of patients (n = 109) completed the PSS at initial visit and 4 weeks later. These scores were used to assess internal consistency and responsiveness. RESULTS: Reliability analysis revealed a test-retest ICC2,1 of 0.94 (95% CI, 0.89-0.97). Internal consistency analysis revealed a Cronbach alpha of 0.93. The standard error of measurement (SEM) was +/- 8.5 scale points (based on a 90% CI) and the minimal detectable change (MDC) was +/- 12.1 scale points (based on a 90% CI). The minimal clinically important difference (MCID) for improvement was 11.4 points. Pearson product moment correlation coefficients between the PSS and the CSS and ASES were 0.85 and 0.87, respectively. Responsiveness analysis revealed an effect size of 1.01 and a standardized response mean of 1.27. CONCLUSIONS: This study has demonstrated that the PSS is a reliable and valid measure for reporting outcome of patients with various shoulder disorders.

Adult↗
PubMed2005

Axillary nerve monitoring during arthroscopic shoulder stabilization.

PURPOSE: This study evaluated the ability of a novel intraoperative neurophysiologic monitoring method used to locate the axillary nerve, predict relative capsule thickness, and identify impending injury to the axillary nerve during arthroscopic thermal capsulorrhaphy of the shoulder. TYPE OF STUDY: Prospective cohort study. METHODS: Twenty consecutive patients with glenohumeral instability were monitored prospectively during arthroscopic shoulder surgery. Axillary nerve mapping and relative capsule thickness estimates were recorded before the stabilization portion of the procedure. During labral repair and/or thermal capsulorrhaphy, continuous and spontaneous electromyography recorded nerve activity. In addition, trans-spinal motor-evoked potentials of the fourth and fifth cervical roots and brachial plexus electrical stimulation, provided real-time information about nerve integrity. RESULTS: Axillary nerve mapping and relative capsule thickness were recorded in all patients. Continuous axillary nerve monitoring was successfully performed in all patients. Eleven of the 20 patients underwent thermal capsulorrhaphy alone or in combination with arthroscopic labral repair. Nine patients underwent arthroscopic labral repair alone. In 4 of the 11 patients who underwent thermal capsulorrhaphy, excessive spontaneous neurotonic electromyographic activity was noted, thereby altering the pattern of heat application by the surgeon. In 1 of these 4 patients, a small increase in the motor latency was noted after the procedure but no clinical deficit was observed. There were no neuromonitoring or clinical neurologic changes observed in the labral repair group without thermal application. At last follow-up, no patient in either group had any clinical evidence of nerve injury or complications from neurophysiologic monitoring. CONCLUSIONS: We successfully evaluated the use of intraoperative nerve monitoring to identify axillary nerve position, capsule thickness, and provide real-time identification of impending nerve injury and function during shoulder thermal capsulorrhaphy. The use of intraoperative nerve monitoring altered the heat application technique in 4 of 11 patients and may have prevented nerve injury. LEVEL OF EVIDENCE: Level II, prospective cohort study.

Adolescent↗
PubMed2005

Treatment of glenohumeral subluxation using electrothermal capsulorrhaphy.

PURPOSE: The purpose of this study was to review the results of a relatively homogenous group of patients with glenohumeral subluxation without labral pathology who were treated with an electrothermal capsulorrhaphy procedure. TYPE OF STUDY: Case series without controls. METHODS: From 1997 to 1998, 42 patients underwent electrothermal capsulorrhaphy using a monopolar radiofrequency probe (Oratec Interventions, Menlo Park, CA). Patients with prior capsular repairs, labral pathology that required repair, or capsular avulsion injuries were excluded from the study. Thirty-one patients met the inclusion criteria. Patients had a minimum of 2 years of follow-up (mean, 25 months), and a mean age of 25 years (range, 16 to 38 years). All of the patients had previously failed conservative treatment. There were 25 patients with unidirectional anterior instability, 2 patients with unidirectional inferior instability, 1 patient with unidirectional posterior instability, and 3 patients with multidirectional instability. The patients were assessed using a modified American Shoulder and Elbow Surgeons (ASES) score that examined pain (30 points), function (60 points), and patient satisfaction (10 points). In addition, subjective stability was assessed using a 10-point scale. RESULTS: The average modified ASES score increased to 88 points from 56 preoperatively (P < .01). The average subjective stability scale increased to 8.5 from 4.4 preoperatively (P < .01). Nineteen patients (61%) had an excellent result, 4 (13%) had a good result, 5 (16%) had a fair result, and 3 (10%) had a poor result; 22 of 26 patients who participated in sports were able to return to their preinjury level of play. The subset of patients with isolated anterior instability had results similar to the overall group. There were no instances of axillary neuritis or other neurologic injury. CONCLUSIONS: In carefully selected patients with shoulder instability, including unidirectional anterior instability without associated labral pathology, electrothermal capsulorrhaphy was effective and had few complications. LEVEL OF EVIDENCE: Level IV, case series without controls.

Adolescent↗
PubMed2005

Arthroscopic versus mini-open rotator cuff repair: a comparison of clinical outcome.

PURPOSE: To compare the outcome of patients who underwent rotator cuff repair using all arthroscopic or mini-open repair techniques. TYPE OF STUDY: Retrospective comparative study. METHODS: We retrospectively reviewed 54 patients who underwent either mini-open or arthroscopic rotator cuff repair. Twenty-six patients underwent mini-open repair and 28 patients had arthroscopic repair. Follow-up averaged 33 months (range, 18 to 48 months) for the mini-open group and 19 months (range, 13 to 26 months) for the arthroscopic group. The patient groups were similar with regard to age, activity level, mechanisms of injury, associated findings at surgery, and tear size measured in square centimeters. The outcome for the 2 groups was evaluated using a modified American Shoulder and Elbow Society (ASES) score. Statistical analysis was performed using Pearson correlations and the Student t test. RESULTS: The tear size averaged 2.7 cm2 for the mini-open group and 2.0 cm2 for the arthroscopic group (P = .754). All patients showed significant improvement in their scores for pain, satisfaction, and function at the time of follow-up. The average preoperative and postoperative scores for the mini-open group were as follows: pain 17 and 27 (30 possible points), satisfaction 3 and 9 (10 possible points), function 32 and 53 (60 possible points), and total 52 and 89 (100 possible points) (P < .05). For patients who underwent arthroscopic repair, average preoperative and postoperative scores were as follows: pain 12 and 26, satisfaction 2 and 9, function 28 and 51, and total, 42 and 86 (P < .05). Improvement in scores within each group was significant, but the difference in total scores between the 2 techniques was not statistically significant. CONCLUSIONS: This study confirms that short-term results for arthroscopic and mini-open rotator cuff repair are similar and supports continued use of arthroscopic repair techniques. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Adult↗
PubMed2005

Rat supraspinatus muscle atrophy after tendon detachment.

Rotator cuff tears are one of the most common tendon disorders found in the healthy population. Tendon tears not only affect the biomechanical properties of the tendon, but can also lead to debilitation of the muscles attached to the damaged tendons. The changes that occur in the muscle after tendon detachment are not well understood. A rat rotator cuff model was utilized to determine the time course of changes that occur in the supraspinatus muscle after tendon detachment. It was hypothesized that the lack of load on the supraspinatus muscle would cause a significant decrease in muscle mass and a conversion of muscle fiber properties toward those of fast fiber types. Tendons were detached at the insertion on the humerus without repair. Muscle mass, morphology and fiber properties were measured at one, two, four, eight, and 16 weeks after detachment. Tendon detachment resulted in a rapid loss of muscle mass, an increase in the proportion of fast muscle fibers, and an increase in the fibrotic content of the muscle bed, concomitant with the appearance of adhesions of the tendon to surrounding surfaces. At 16 weeks post-detachment, muscle mass and the fiber properties in the deep muscle layers returned to normal levels. However, the fiber shifts observed in the superficial layers persisted throughout the experiment. These results suggest that load returned to the muscle via adhesions to surrounding surfaces, which may be sufficient to reverse changes in muscle mass.

Animals↗
PubMed2004

Supraspinatus tendon organizational and mechanical properties in a chronic rotator cuff tear animal model.

Rotator cuff tears of the shoulder are a common cause of pain and disability. The successful repair of rotator cuff tendon tears depends on the time from onset of injury to the time of surgical repair. However, the effect of time from injury to repair remains poorly understood. A rat model was used to investigate the supraspinatus tendon organizational and mechanical property changes that occur with time post-injury to understand the natural injury response in the absence of repair. It was hypothesized that increased time post-injury would result in increased detrimental changes to tendon organizational and mechanical properties. Tendons were detached at the insertion on the humerus without repair and the quantitative organizational and mechanical properties were analyzed at 1, 2, 4, 8, and 16 weeks post-detachment. Tendon detachment resulted in a dramatic decrease in mechanical properties initially followed by a progressive increase with time. The quantitative collagen fiber orientation results provided corroborating support to the mechanical property data. Based on similarities in histology and mechanical properties to rotator cuff tears in humans, the animal model presented here is promising for future investigations of the tendon's natural injury response in the absence of repair.

Animals↗
PubMed2004

Outcome of open reduction and internal fixation of surgical neck nonunions of the humerus.

OBJECTIVE: The purpose of this study was to evaluate the results of open reduction and internal fixation of nonunions of the surgical neck of the humerus. DESIGN: Retrospective review of patients who underwent operative treatment of a surgical neck of the humerus nonunion. SETTING: Shoulder and elbow service at two university centers. PATIENTS: Thirteen patients with a two-part nonunion of the surgical neck of the humerus who were treated with open reduction and internal fixation with bone graft with a minimum of 12 months' follow-up were included. Patients with avascular necrosis, posttraumatic arthritis, severe humeral head bone loss, or a nonunion of one of the two tuberosities were excluded. INTERVENTION: Open reduction and internal fixation with either a blade plate or a T-plate and autogenous bone graft. MAIN OUTCOME MEASURES: Medical records, operative reports, physical examination, and preoperative and postoperative radiographs were reviewed. Outcome was assessed using Neer's criteria for the evaluation of total shoulder arthroplasty, visual analogue pain scale, range of motion, and ability to perform activities of daily living.RESULTS The results were excellent in 11 patients, satisfactory in 1 patient, and poor in 1 patient. The 11 nonunions in patients with excellent results healed within 6 months. The patient with the poor result initially had a persistent nonunion and required revision, open reduction and internal fixation, and bone grafting. This patient healed and went on to have an excellent result at final follow-up. All fractures were healed at the time of this study. Pain scores decreased from an average of 4.2 preoperatively to 1.2 postoperatively on a 5-point pain scale. Forward elevation in the scapular plane improved from 24 degrees preoperatively to 144 degrees postoperatively. All patients but one were able to attain overhead elevation. All patients were able to perform activities of daily living, such as dressing, bathing, combing hair, and performing perineal care, at final follow-up. Overall satisfaction increased from an average of 1.0 to 9.4 on a 10-point visual analogue scale. CONCLUSIONS: Open reduction and internal fixation with autogenous bone graft results in excellent outcomes even in patients >65 years old and patients with significant medical problems. This treatment method offers predictable fracture healing and has a low complication rate.

Activities of Daily Living↗
PubMed2004

The tension required at repair to reappose the supraspinatus tendon to bone rapidly increases after injury.

Rotator cuff tears occur frequently and can cause significant pain and reduced shoulder function. A high percentage of patients are satisfied after surgical repair of rotator cuff tears, but a smaller percentage of patients with chronic tears continue to have pain and poor shoulder function. This may be partly attributable to an increase in the repair tension, the force required at repair to reappose the tendon to its original insertion site on the humerus. Increases in repair tension have been shown to occur for long-standing ruptures of the supraspinatus tendon, but the precise tension at various times after injury are unknown. Therefore, the objective of the current study was to determine the repair tension at various times after a rotator cuff tear. This was achieved by creating a full-thickness supraspinatus tendon tear in a rat model and measuring the mechanical characteristics of the musculotendinous unit at 0, 2, 4, 9, and 16 weeks after injury. The repair tension rapidly increased initially after injury followed by a progressive, but less dramatic, increase with additional time. These findings suggest that rotator cuff tears should be repaired early in the clinical setting. Future studies will investigate the effect of repair tension on tendon to bone healing after repair.

Animals↗
PubMed2004

Nonprosthetic management of proximal humeral fractures.

Many proximal humeral fractures can be treated without the need for hemiarthroplasty. Treatment choice is affected by fracture location and pattern, as well as by patient factors including age, activity level, quality of bone, and ability to comply with a regimen of therapy. Successful diagnosis and treatment of proximal humeral fractures is dependent on good-quality radiographs, but in some cases, intraoperative assessment of the fracture pattern is required for a complete and accurate diagnosis of the fracture pattern and severity. A discussion of nonsurgical and surgical treatment options and techniques needed to achieve anatomic reduction and stable fixation is important.

Fracture Fixation, Internal↗
PubMed2003

Clinical evaluation of injuries to the acromioclavicular and sternoclavicular joints.

Acromioclavicular injuries are common and most often can be accurately diagnosed using history, physical examination, and routine radiography. Sternoclavicular subluxations and dislocations may also be accurately characterized with only history, physical examination, and routine radiography (i.e., serendipity view). In many cases of sternoclavicular dislocation, however--especially posterior--CT scanning or MR imaging will be necessary. Posterior sternoclavicular dislocation may cause compression of mediastinal structures. When this is suspected, angiography or CT angiography is indicated. Physeal injuries should be suspected at either end of the clavicle in adolescent patients.

Acromioclavicular Joint↗