Dynamic Magnetic Resonance Imaging Protocol: An Effective and Useful Tool to Assess Discoid Lateral Meniscus Instability in Children.

OBJECTIVES: One of the most common symptoms in cases of discoid lateral meniscus (DLM) in children is a "snapping" knee. The clock in extension, followed by a pop in flexion, perceived by the clinician, reflects the meniscal displacement caused by the peripheral meniscocapsular detachment. Standard magnetic resonance imaging (MRI) results in a 40% false-negative rate for detecting this instability. The hypothesis was that a dynamic MRI protocol could reduce the false negative rate and improve the efficiency of the MRI in detecting the direction of instability. METHODS: Eight DLM knees (8 patients) with snapping knees (grade 2 of Lyon's classification) were included in this monocentric prospective preliminary study in a referral center of pediatric orthopaedic surgery. Every patient underwent a dynamic MRI protocol with both T2-Fat-Sat sagittal and coronal slices, performed "after the clock" and again "after the pop" in a knee with standard 20 degrees of flexion during acquisition. All the MRI data were correlated with an arthroscopic description of the peripheral tear of the DLM according to Ahn's classification to assess for diagnostic accuracy. RESULTS: The standard MRI protocol resulted in a false-negative rate of 50% for detecting the direction of instability. The dynamic MRI protocol allowed the identification of, and classification of the meniscal instability, meniscal shift, and meniscocapsular tear in 8 of 8 patients (0% false-negative rate), perfectly correlated with arthroscopic findings. CONCLUSION: This preliminary series, although short, allowed us to understand all the types of movements and lesions associated with the child's discoid meniscus. The detailed case analysis showed a strong benefit of such a protocol for planning the surgical suture procedure. The functionality and reliability of the dynamic MRI protocol is a good and method relatively simple method which does not require specific equipment, minimizing any additional cost compared with standard MRI. LEVEL OF EVIDENCE: Level IV.

Frontal correction assessment in severe adolescent idiopathic scoliosis surgery using halo gravity traction before to posterior vertebral arthrodesis: a multicenter retrospective observational study.

PURPOSE: Preoperative preparation with halo gravity traction (HGT) has several advantages but is still controversial. A multicenter, observational, retrospective study was conducted to determine whether HGT provides better frontal correction in surgery for adolescent idiopathic scoliosis (AIS). METHODS: Between 2010 and 2020, all patients who underwent posterior spinal fusion (PSF) AIS with a Cobb angle greater than 80° were included. The included patients who underwent HGT were compared (complications rate and radiographic parameters) to patients who did not undergo traction (noHGT). For patients who underwent HGT, a spinal front X-ray at the end of the traction procedure was performed. RESULTS: Sixty-four in noHGT and forty-seven in HGT group were analyzed with a 31-month mean follow-up. The mean ratio of Cobb angle correction was 58.8% in noHGT and 63.6% in HGT group (p = 0.023). In HGT, this ratio reached 9% if the traction lasted longer than 30 days (p = 0.009). The complication rate was 11.7% with a rate of 6.2% in noHGT and 19.1% in HGT group (p = 0.07). In patient whose preoperative Cobb angle was greater than 90°, the mean ratio of Cobb angle correction increases to 6.7% (p = 0.035) and the complications rate increased to 14% in the no HGT group and decreased to 13% in the HGT group (p = 0.9). CONCLUSION: HGT preparation in the management of correction of AIS with a Cobb angle greater than 90° is a technique providing a greater frontal correction gain with similar complication rate than PSF correction alone. We recommend a minimum halo duration of 4 weeks.

Arthroscopic Suture-Saucerization of Discoid Meniscus Allows Volume Conservation but Does Not Fully Restore Coverage.

Purpose: The purpose of this study was to quantify the effect of meniscoplasty suture-saucerization on volume and surface coverage of lateral discoid menisci. Methods: This retrospective study included all consecutive 10 patients treated between 2014 and 2019 who had magnetic resonance imaging before and after surgery and 15 controls. The MITK 3M3 semiautomatic software was used to segment the meniscus and cartilage before and after surgery to measure the percentage of meniscus coverage on the tibial cartilage. Results are compared to control patients without knee pathology matched on sex and age with Student t test. Results: Discoid meniscus surface and volume before surgery were respectively 597 mm2 (range, 550-887 mm2) and 2,822 mm³ (1,571-3,407 mm³), representing 74.5% (56%-89%) of the tibial cartilage surface. After surgery, it decreased to 422 mm2 (229-569 mm2) and 1,235 mm³ (680-1,738 mm³), leading to 45.7% (22.5%-68.6%) coverage. In the control group, median surface was 457 mm2 (314-641 mm2), volume was 1,321 mm3 (641-2,240 mm3), and tibial coverage was 55% (41%-77%). Altogether, meniscus volume after surgery was similar to normal, while coverage was significantly lower than controls (P = .04). Conclusions: Meniscoplasty suture-saucerization procedure may allow meniscus sparing and restauration of a similar to normal meniscus volume. Meniscus surface and coverage are diminished compared to controls. Both surface and volume normalization is usually not achievable without decreasing the thickness of the rather thick discoid meniscus. Clinical Relevance: Both surface and volume normalization is usually not achievable without decreasing the thickness of thick discoid menisci.

Rectus femoris surgery for the correction of stiff knee gait in cerebral palsy: A systematic review and meta-analysis.

INTRODUCTION: Rectus femoris (RF) transfer was long the gold-standard treatment for stiff knee gait (SKG), but efficacy now seems less than that of distal RF release. The aim of the present study was to compare efficacy between the two. The study hypothesis was that both significantly improve 4 knee kinematic parameters at 1 year. PATIENTS AND METHOD: A meta-analysis was performed, using PRISMA criteria, on the Medline, Science Direct, Cochrane Registry, Scopus and Pascal databases. Search was conducted up to March 1, 2020 by two authors (A.J & M.T). Study methodology was assessed on MINORS index. Inclusion criteria comprised patients with SKG, treated by RF transfer or distal release. Endpoints comprised: Peak Knee Flexion in swing phase (PKFSW), Knee Range of Motion (KROM), time to Peak Knee Flexion (t-PKFGC), and Maximum Knee Extension in stance phase (MKEST). Effect size was assessed on Standard Mean Deviation (SMD). RESULTS: A total of 695 studies were identified, 16 of which were included: 14 transfer, 5 release. Data were analyzed for 1,079 limbs in 768 patients. Only transfer improved PKFSW, with small effect size (SMD=0.29). The other three parameters were improved by both techniques, with moderate effect size. DISCUSSION: Results showed improved knee kinematics after RF transfer, but with small or moderate effect size. The effect of distal release on PKF could not be assessed, due to publication bias. The heterogeneity of studies and low levels of evidence call for caution in interpreting the present results. LEVEL OF EVIDENCE: III.

Medial unilateral knee arthroplasty after high tibial osteotomy: A retrospective study of 41 cases.

INTRODUCTION: When medial knee osteoarthritis continues to get worse after a high tibial osteotomy (HTO) procedure, a subsequent total knee arthroplasty (TKA) is typically warranted. Medial unilateral knee arthroplasty (UKA) is not recommended. The aim of this study was to evaluate the outcomes of patients who underwent medial UKA after HTO. HYPOTHESIS: Good results can be obtained with this procedure, as long as the postoperative valgus is not excessive. MATERIALS AND METHODS: This was a retrospective, single-center study of patients operated between January 2005 and June 2019. The primary endpoint was the Oxford Knee Scale (OKS). The Knee injury and Osteoarthritis Outcome Score (KOOS) and the Western Ontario and McMaster Universities osteoarthritis index (WOMAC), range of motion and complications were the secondary endpoints. The average follow-up was 79 months. RESULTS: Forty-one knees in 38 patients were analyzed. Four revisions with implant exchange (10%) were needed. Thirty-seven knees had a mean OKS of 20/60±8 (12-39). The mean flexion and extension amplitude were 123°±8° (110-140) and -1.5°±4 (-15-0), respectively. Eight patients had flexion and/or extension contractures. DISCUSSION: Good functional and clinical outcomes in the medium term were achieved for the patients in this study who underwent UKA after HTO. These findings reinforce the good results reported in recent studies of UKA after HTO. LEVEL OF EVIDENCE: IV, Retrospective study.

Correlations between physical and ultrasound findings in congenital clubfoot at birth.

BACKGROUND: At birth, clinical classifications are the only available tools for evaluating the severity of congenital clubfoot. Ultrasound provides an assessment of the anatomical abnormalities. The objective of this study was to assess correlations between physical and ultrasound findings at birth. HYPOTHESIS: Physical and ultrasonography provide different findings in congenital clubfoot and should therefore be used in conjunction. MATERIAL AND METHOD: One hundred and forty-five clubfeet in 108 patients born between 2006 and 2010 were included in a retrospective study. Clubfoot severity was classified using two methods, the modified Dimeglio classification based on physical findings and an ultrasound score based on the talo-navicular angle (TNA) and metaphyso-talo-calcaneal angle (MTCA). Each of these two methods distinguished three severity grades. Agreement between the two methods was assessed by computing the coefficient. RESULTS: The results confirmed the hypothesis by showing low agreement between the clinical and ultrasound classifications. The severity grades were identical with the two methods for only 83/145 (57%) feet. The coefficient was 0.086. DISCUSSION: The two ultrasound views used to measure the TNA and MTCA, respectively, added an assessment of the three main deformities that characterise congenital clubfoot (equinus, adduction of the forefoot, and adduction of the calcaneo-pedal unit). Ultrasonography complements the physical examination at birth. In the future, using both physical examination and ultrasound scanning to monitor babies with clubfoot may allow early treatment adjustments aimed at optimising the outcome. LEVEL OF EVIDENCE: IV, retrospective observational study.