Optimal immobilization position for conservative treatment of proximal humerus fractures by fracture type: a biomechanical cadaveric study.

In conservative treatment for proximal humerus fractures (PHFs), the immobilization position of the affected arm should not be determined uniformly. The aim of this study is to investigate the optimal immobilization position for conservative treatment of different types of PHFs. We hypothesized that the optimal position minimizing the deforming force in PHFs depends on the fracture components involved. PHF models involving either the surgical neck (SN) or greater tuberosity (GT) were created using 12 fresh-frozen cadaveric shoulders. In the SN model, the deforming forces on the pectoralis major muscle were measured in full adduction by increasing external rotation. In the GT model, the deforming force of the supraspinatus muscle was measured in neutral rotation by decreasing abduction, and the deforming force of the infraspinatus muscle was measured in full adduction by increasing internal rotation, respectively. In the SN model, the deforming force of the pectoralis major muscle increased significantly with external rotation from full internal rotation to neutral rotation (P = 0.006), indicating that the arm should be placed in full internal rotation. In the GT model, the deforming force of the supraspinatus muscle increased significantly with adduction from 45° of abduction to full adduction (P = 0.006); the deforming force of the infraspinatus muscle increased significantly with internal rotation from neutral rotation to full internal rotation (P = 0.006). These findings should be considered when placing the arm in abduction and neutral rotation so as to minimize the deforming force by either the supra or infraspinatus muscle. In conservative treatment for PHFs, the affected arm should be placed in a position that minimizes the deforming force on the fracture components involved.

Peri-anchor cyst formation after arthroscopic bankart repair: comparison between biocomposite suture anchor and all-suture anchor.

BACKGROUND: The purpose of this study is to investigate clinical outcomes and radiological findings of cyst formation in the glenoid around suture anchors after arthroscopic Bankart repair with either biocomposite suture anchor or all-suture anchor in traumatic anterior shoulder instability. We hypothesized that there would be no significant difference in clinical and radiological outcomes between the two suture materials. METHODS: This retrospective study reviewed 162 patients (69 in group A, biocomposite anchor; 93 in group B, all-suture anchor) who underwent arthroscopic Bankart repair of traumatic recurrent anterior shoulder instability with less than 20% glenoid defect on preoperative en-face view three-dimensional computed tomography. Patient assignment was not randomized. RESULTS: At final follow-up, the mean subjective shoulder value, Rowe score, and University of California, Los Angeles shoulder score improved significantly in both groups. However, there were no significant differences in functional shoulder scores and recurrence rate (6%, 4/69 in group A; 5%, 5/93 in group B) between the two groups. On follow-up magnetic resonance arthrography/computed tomography arthrography, the incidence of peri-anchor cyst formation was 5.7% (4/69) in group A and 3.2% (3/93) in group B, which was not a significant difference. CONCLUSIONS: Considering the low incidence of peri-anchor cyst formation in the glenoid after Bankart repair with one of two anchor systems and the lack of association with recurrence instability, biocomposite and all-suture anchors in Bankart repair yield satisfactory outcomes with no significant difference.

Radiographic Assessment of Foot Alignment in Juvenile Hallux Valgus and Its Relationship to Flatfoot.

BACKGROUND: The relationship between juvenile hallux valgus (JHV) and flatfoot has not been clearly established. The aim of this study was to assess radiographic measurements in feet with JHV compared with matched controls and to investigate whether the foot alignment of JHV is related to flatfoot. METHODS: We retrospectively reviewed 163 patients with JHV as defined as hallux valgus angle greater than 20 degrees and intermetatarsal greater than angle than 10 degrees. Patients with open physes of the feet and who had weight-bearing radiographs of the feet were included. Another 55 normal participants served as controls. Patients with JHV were divided into 2 subgroups: Group 1 included patients with asymptomatic JHV and group 2 consisted of those treated with correctional surgery for painful JHV. Twelve radiographic indices were analyzed, including calcaneal pitch angle, tibiocalcaneal angle, talocalcaneal angle, naviculocuboid overlap, talonavicular coverage angle, lateral talo-first metatarsal angle, anteroposterior talo-first metatarsal angle, metatarsus adductus angle, hallux valgus angle, intermetatarsal angle, distal metatarsal articular angle, and first metatarsal cuneiform angle. The groups were compared by age, gender, and the above radiographic parameters. RESULTS: There was no significant difference in hindfoot alignment of patients with JHV and controls. Naviculocuboid overlap (P <.001), lateral talo-first metatarsal angle (P = .002), and metatarsus adductus angle (P = .004) were significantly greater in patients with JHV than in controls, whereas the anteroposterior talo-first metatarsal angle (P = .026) was significantly less. Symptomatic and asymptomatic JHV patient subsets showed no significant radiologic differences. CONCLUSION: Radiographic profiles in patients with JHV were inconsistent with regard to features of flatfoot, and foot alignment was unrelated to the presence of symptoms or degree of deformity in JHV. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

A comparative evaluation of tibial metaphyseal-diaphyseal angle changes between physiologic bowing and Blount disease.

The purpose of this study was to estimate the rate of spontaneous improvement in tibial metaphyseal-diaphyseal angle (TMDA) in physiologic bowing in comparison to that in Blount disease and to provide reference values of TMDA for monitoring patients with highly suspected to have Blount disease.We retrospectively reviewed patients with physiologic bowing meeting the following criteria:(1) TMDA greater than 9° before 36 months of age at initial evaluation;(2) two or more standing long bone radiographs available; and(3) follow-up conducted up to resolution of deformity.Patients with Blount disease had(1) more than 2 standing long bone radiographs obtained before 36 months of age and(2) underwent no treatment during the period in which these images were obtained.TMDA measurements were obtained from 174 patients with physiologic bowing and 32 patients with Blount disease. Rates of TMDA improvement were adjusted by multiple factors using a linear mixed model, with sex and laterality as fixed effects and age and individual patients as the random effects.In the physiologic bowing group, TMDA improved significantly, by 3° per 6 months and by 6° per year. Changes in TMDA were not significant in the Blount disease group.Knowing the rate of TMDA change can be helpful for physicians seeking to monitor infants with suspected as having Blount disease with a high TMDA and to avoid unnecessary repeat radiographic evaluations.

The Fate of the Contralateral Knee in Patients With a Lateral Discoid Meniscus.

PURPOSE: To analyze the survivorship of the lateral meniscus (LM) in the contralateral knee after surgery for symptomatic torn discoid lateral meniscus (DLM) and to determine its associated factors. METHODS: Two hundred ninety-six patients who underwent arthroscopic meniscectomy for torn symptomatic DLM were reviewed retrospectively. Patients were classified into subgroups based on demographic, clinical, and radiologic variables. The survivorship analysis of the LM on the contralateral knee was calculated using the Kaplan-Meier method, and comparison among the subgroups was conducted using the log-rank test. The predicted prognostic factors associated with survivorship were determined using Cox proportional hazard regression analysis. RESULTS: Of the 296 patients, 51 (17%) had arthroscopic surgery in the contralateral knee during the study period. The group ≥40 years old had significantly worse survival than the group <40 (log-rank test, P < .001). In terms of radiologic variables, the group with Kellgren-Lawrence grade 3 or 4 had significantly poorer survivorship than that with grade 1 or 2 (log-rank test, P = .045). Age ≥40 years was associated with poorer survivorship (hazard ratio, 3.235; 95% confidence interval, 1.782-5.875; P < .001). Kellgren-Lawrence grades 3 and 4 in the contralateral knee were associated with poorer survival (hazard ratio, 2.071; 95% confidence interval, 1.061-4.043; P = .033). The cumulative survival rate at 10 years of the LM in the contralateral knee after surgery for symptomatic torn DLM was 81%. CONCLUSIONS: Patients with a lateral discoid meniscus have a risk of a similar condition in the contralateral knee. Increased risks of symptomatology are associated with age and degenerative changes. LEVEL OF EVIDENCE: Level IV, retrospective uncontrolled case series.

Preoperative Diagnosis and Treatment Outcomes of Incarcerated Inferiorly Displaced Flap Tear of the Medial Meniscus: Comparison between Flap Tears with and without Incarcerated Fragment.

The purpose of this study was to compare preoperative variables and postoperative outcomes between flap tears with and without incarceration of inferiorly displaced fragments of medial meniscus and find distinct features of incarcerated flap tear of medial meniscus to improve preoperative diagnosis. 79 patients who underwent partial meniscectomy for flap tear of medial meniscus were classified into two groups: group U, usual flap tear without incarcerated fragment; group I, flap tear with incarcerated inferiorly displaced fragment. Patient characteristics and preoperative variables including duration of symptom aggravation were investigated. A comprehensive physical examination including joint line tenderness was performed. Magnetic resonance imaging (MRI) examination was carried out on all patients. Clinical assessments were performed with functional scores including visual analogue scale (VAS), and radiologic evaluation was conducted. Preoperative values and postoperative outcomes measured at the minimum follow-up duration of 2 years were compared between the groups. The groups did not differ significantly regarding postoperative outcomes by functional and radiological evaluations (p > 0.05). In making preoperative diagnosis, sensitivity of diagnosis based solely on MR images was significantly lower in group I (68.8%) than that in group U (90.5%) (p = 0.040). The following clinical features differed significantly between the groups: Patients in group I had higher scores in preoperative VAS (group U = 6.6; group I = 7.7) (p = 0.011) and shorter duration of symptom aggravation (group U = 13.8 weeks; group I = 3.9 weeks) (p < 0.001). Joint line tenderness was positive more distinctly in group I (100%) than in group U (74.6%). If displaced flap tear was properly resected, improved outcomes did not differ regardless of incarceration of flap tear. In diagnosing incarcerated inferiorly displaced flap tear, sensitivity of diagnosis based solely on MR images could be low. Distinguishing clinical findings would be helpful in obtaining a more appropriate diagnosis.