[Experience in COVID-19 in hospitalized patients in pediatric critical units during pandemic period]. / Experiencia en COVID-19 en pacientes hospitalizados en unidades de paciente crítico pediátrico durante el periodo pandémico.

OBJECTIVES: To characterize the COVID-19 disease profile in Chilean children hospitalized in pediatric intensive care units (PICU) and to evaluate risk factors associated with severe COVID-19. PATIENTS AND METHOD: A multicenter prospective cohort study with patients 0-18 years of age with confirmed SARS-CoV-2 hospitalized in PICU. Clinical, laboratory, imaging, and therapeutic variables were recorded. We compared "mild/moderate COVID-19" with ''severe COVID-19" using median with interquartile range (IQR), Mann-Whitney U test, two-tailed Fisher's test, and forward binary multivariate analysis to adjust variables for "severe COVID-19". A p < 0.05 was considered significant. RESULTS: From 16 PICUs, 219 patients were recruited, 55.3% were male, with a median age of 86 months (IQR: 13.5-156). The most frequent comorbidities were obesity and respiratory diseases. Overall mortality was 3.6%. "Severe COVID-19" (26.5%) showed more leukopenia, lymphopenia, increased inflammatory parameters, and altered organ function (p < 0.05). It also developed more sepsis/shock, ARDS, and organ dysfunction, requiring more hemodynamic, anti-inflammatory, anticoagulation, and antibiotic therapy, with a longer stay in the PICU/hospital (p < 0.05), and 13.8% of mortality. Risk factors associated with "severe COVID-19" were shock on admission to the PICU [aOR 28.44 (95%CI 10.45-77.4)], obesity [aOR 3.55 (95%CI 1.3-9.6)], consolidation [aOR 3.1 (95%CI 1.1 -8.7)], atelectasis [aOR: 8.7 (95%CI 1.17-64.3)], stress dose of corticosteroids [aOR 7.7 (95%CI 1.9-30.6)], early antibiotic therapy [aOR: 12.02 (95%CI 1.11-130.02)], acquired/congenital immunodeficiency [aOR: 19.2 (95%CI: 1.19-321)], and oncological pathology [aOR 10.7 (95%CI 2.14-47.8)]. CONCLUSION: In this Chilean pediatric cohort, most patients with COVID-19 admitted to de PICU were male, of school age, with associated comorbidity. Risk factors for developing severe COVID-19 were the presence of comorbidities such as acquired/congenital immunodeficiency, oncological pathology, and obesity, in addition to shock on admission and consolidations on X-rays.

Evaluation of atraumatic hip instability measured by triaxial accelerometry during walking.

Hip joint instability has been targeted as an important issue that affects normal hip function. The diagnosis of hip instability could be very challenging and currently, there is no definitive diagnostic test. Hip instability results in an excessive amount of translation of femoroacetabular articulation, leading to changes on the dynamic loading of the hip. These changes in femoroacetabular translation could be evaluated by human movement analysis methods. The purpose of this study was to describe the triaxial and overall magnitude of acceleration in patients diagnosed with hip instability during gait cycle and compare those results with a control group. Our hypothesis was that acceleration values obtained from the instability group would be higher than asymptomatic controls. Ten patients with previously diagnosed hip instability were included and 10 healthy and asymptomatic subjects were enrolled as control group. Triaxial accelerometers attached bilaterally to the skin over the greater trochanter were used to record acceleration during walking on a treadmill. The overall magnitude of acceleration and the axial, anteroposterior and mediolateral accelerations (x/y/z) were obtained during gait. Mean overall magnitude of acceleration was higher in the hip instability group compared with the control group, 1.51 g (SD: 0.23) versus 1.07 g (SD: 0.16) (P = 0.022). The axial, anteroposterior and mediolateral accelerations significantly differed between the two groups. The axial and mediolateral accelerations showed to be higher for the hip instability group while the anteroposterior axis acceleration was lower.

Outcome of Revision Total Hip Arthroplasty in Management of Failed Metal-on-Metal Hip Arthroplasty.

BACKGROUND: This is a retrospective review of the functional outcomes and complications of revision total hip arthroplasty (THA) of failed metal-on-metal (MoM) hip arthroplasty. METHODS: A total of 20 revision THAs were performed in 19 patients. Of them, 2 cases were failed hip resurfacing, and 18 cases were failed (MoM) THA. The mean age at revision (THA) was 59.35 years (standard deviation [SD] 9.83). RESULTS: The mean follow-up was 45 months (SD 13.98). The indications of revision were aseptic loosening of acetabular component without adverse local tissue reaction (ALTR; 10 hips), aseptic loosening of the acetabular and femoral components without ALTR (1 hip), painful hip associated with ALTR (6 hips), iliopsoas impingement associated with a large-diameter femoral head or malpositioned acetabular component (3 hips). The acetabular components were revised in 18 hips using Trabecular Metal Modular cups. The femoral components were revised in 3 hips. A constrained acetabular liner was used in 5 hips. The Harris hip score significantly improved from 48.4 (SD 12.98) to 83.25 (SD 10.08). There were 2 complications (1 foot drop and 1 superficial infection) and 1 failure (recurrent dislocation) that required revision to a constrained liner. CONCLUSION: Early results of revision THA of failed MoM hip arthroplasty showed improvement in pain and functional outcome. No case of failed bone ingrowth was noted with the use of Trabecular Metal Modular cups. Extensive soft tissue and abductor muscles dysfunctions were common. A constrained acetabular component with repair of the hip abductors might be beneficial.

Promising Mid-term Results With a Cup-cage Construct for Large Acetabular Defects and Pelvic Discontinuity.

BACKGROUND: Restoring normal anatomy and achieving stable fixation of the acetabular component can be especially challenging when the surgeon must deal with severe acetabular defects and/or pelvic discontinuity. The cup-cage (CC) construct, where an ilioischial cage is cemented within a biologically fixed porous metal cup, has emerged as an excellent option to treat such challenges. QUESTIONS/PURPOSES: We sought to determine (1) mid-term Kaplan-Meier survival; (2) clinical outcomes based on Merle d'Aubigné-Postel scores; (3) radiological outcomes based primarily on construct migration; and (4) the complication rate for a series of 67 CC procedures performed at our institution. METHODS: All hip revision procedures between January 2003 and March 2012 where a CC was used (with the exception of tumor cases or acute fracture; four total cases) that had a minimum 2-year followup and that had been seen within the last 2 years were included in this retrospective review. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven CC procedures with an average followup of 74 months (range, 24-135 months; SD, 34.3) months were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Postoperative clinical and radiological evaluation was done annually. Merle d'Aubigné-Postel scores were recorded and all radiographs were compared with the 6-week postoperative radiographs to evaluate for radiographic loosening or migration. Failure was defined as revision surgery for any cause, including infection. RESULTS: The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval [CI], 83.1-97.4), and the 10-year survival rate was 85% (95% CI, 67.2-93.8). The Merle d'Aubigné-Postel score improved significantly from a mean of 6 preoperatively to 13 postoperatively (p < 0.001). Four CC had nonprogressive radiological migration of the ischial flange and they remain stable. CONCLUSIONS: We believe that the CC construct is a suitable choice to treat chronic pelvic discontinuity; it also remains a reliable option for the treatment of severe acetabular bone defects if stable fixation cannot be obtained through the use of a trabecular metal cup with or without augments. LEVEL OF EVIDENCE: Level IV, therapeutic study.

The focally constrained liner is a reasonable option for revision of unstable total hip arthroplasty.

PURPOSE: Revision surgery for a patient with previous recurrent dislocations or abductor muscle dysfunction has been considered to be a complication-prone procedure regardless of the type of constrained implant used. We investigated the survivorship of a focally constrained acetabular liner used for revision total hip arthroplasty in patients with abductor insufficiency or previous recurrent dislocations. METHODS: We retrospectively reviewed 98 patients in whom a focally constrained acetabular liner was used to treat abductor insufficiency or previous recurrent dislocations. The mean age was 69.4 years (37-92) and 64 of these were females. Previously, the patients had undergone a mean of two (1-5) revisions. The mean follow-up was 38 (12-66) months. Kaplan-Meier survival curves were calculated and Log-rank test was used to test the difference in survivorship between patients with abductor insufficiency and previous dislocations. RESULTS: Sixteen patients needed a further re-revision for any cause. Thus, the revision-free survivorship was 84.3 % at five years. Five patients suffered a dislocation with a mean of five months post-operatively and were managed with repeat revision. Five patients failed at the implant-host bone interface. Three of these failures occurred after cementing the constrained liner into a pre-existing shell. CONCLUSIONS: The focally constrained liner provided a reasonable option for revision total hip arthroplasty in patients with hip instability. Failures were observed in patients with acetabular osteolysis but seemingly well-fixed component and unrecognized impingement.

Prevalence of FAI radiographic hip abnormalities in elite soccer players: are there differences related to skeletal maturity?

BACKGROUND: Femoroacetabular impingement (FAI) can be a source of hip pain in young adults. Some reports have revealed that participation in high-impact sports may play a role in the development of cam deformity, and there is a higher prevalence of signs of cam impingement in asymptomatic adolescents who participate in soccer and basketball than in non-athlete controls; however, current evidence is scarce regarding the initiation and development of deformities. PURPOSE: The aim of this study was to evaluate the prevalence of radiographic hip abnormalities related to FAI in young elite soccer players and compare this with findings in a group of adult elite soccer players. SUBJECTS AND METHODS: Anteroposterior pelvic and cross-table hip radiographs were obtained for 75 young elite soccer players with skeletal immaturity (group 1) and for 75 adult elite soccer players (group 2), all of whom were previously asymptomatic and had no history of hip disease. After exclusion, group 1 included 72 patients, and group 2 included 70 patients. Radiological signs of FAI were evaluated. RESULTS: 34 subjects in groups 1 and 2 demonstrated cam morphology. The prevalence of pincer morphology was 30 in group 1 and 36 in group 2. However, these differences were not statistically significant. CONCLUSION: We found no differences in the prevalence of FAI radiological signs between soccer players in their late adolescence and adult soccer players.

Vancouver type B2 and B3 periprosthetic fractures treated with revision total hip arthroplasty.

PURPOSE: Periprosthetic fractures are the fourth most common cause for hip revision and a devastating complication. Our purpose is to report results and quality of life following revision THA for Vancouver B2 and B3 fractures. METHODS: This was a retrospective review from January 2000 to November 2012 to identify all revision THA performed for Vancouver types B2 and B3 that had a minimum follow-up of two years. Routine post-operative and radiographic evaluation to assess patient survival, implant failure, complications and quality of life was involved. Statistical analysis was made with the Kaplan-Meier survival curve with 95 % confidence interval and the log rank (Mantel-Cox) test. RESULTS: A total of 76 fractures were included, with an average follow-up 74.4 months. Mean age at the revision surgery was 75.7 years (range, 41-97 years; SD, 12.4). Sixty-six cases were classified as Vancouver B2 and treated with distal fixation stem. Ten cases were Vancouver B3 and a proximal femoral allograft technique was used. The overall five-year Kaplan-Meier survival rate for the patients was 77.9 % (95 % CI, 67.4-88.4), and the ten-year rate was 65.1 % (95 % CI, 51.4-78.8). Five-year Kaplan-Meier survival rate for the implants was 89.6 % (95 % CI, 82.2-97); we presented seven failures. The mean SF-12 mental was 55.1 (range, 31-68; SD, 8.1) and the physical was 37.4 (range, 16-55; SD, 9.4). CONCLUSION: Mortality rate after periprosthetic fractures is high as compared to other hip surgeries; our Kaplan-Meier analysis showed that it tends to plateau after five years. In our series the failure rate was low and occurred early in the post-operative period.

Total hip arthroplasty using a short-stem prosthesis: restoration of hip anatomy.

PURPOSE: To evaluate hip parameters such as vertical centre of rotation (VCR), horizontal centre of rotation (HCR), femoral offset, and leg length after total hip arthroplasty (THA) using the Nanos short-stem prosthesis. METHODS: Medical records of 73 men and 74 women aged 25 to 92 (mean, 63) years who underwent THA using the Nanos short-stem prosthesis by a single surgeon were reviewed. Prior to the surgery, the optimal cup and stem size, head length, and level of the neck osteotomy were determined using radiographs. Intra-operatively, the leg length and femoral offset were checked, and the level of neck resection and head length were adjusted. VCR, HCR, femoral offset, and leg length of the operated and contralateral sides were compared. Functional outcomes were assessed using the Harris Hip Score (HHS). RESULTS: Compared with the normal contralateral hips, the operated hips had a mean increase of 0.4 mm in VCR (p=0.032), a mean decrease of 1.4 mm in HCR (p=0.027), a mean increase of 0.6 mm in femoral offset (p=0.043), and a mean increase of 0.36 mm in leg length (p=0.035). For these respective parameters, the difference between the normal contralateral side and the operated side was within 5 mm in 89%, 80%, 71%, and 96% of patients. The HHS improved from a mean of 53 to 91 at one year (p<0.001). CONCLUSION: THA using the Nanos short-stem prosthesis enabled restoration of hip anatomy (VCR, HCR, femoral offset, and leg length).

Reliability of 3 Different Arthroscopic Classifications for Chondral Damage of the Acetabulum.

PURPOSE: To report the interobserver and intraobserver reliability of 3 chondral damage classifications used to assess articular cartilage damage during hip arthroscopy. METHODS: A prospective multicenter study was performed during April and May 2013. Inclusion criteria were all patients who underwent hip arthroscopy for femoroacetabular impingement (FAI) and had evidence of chondral damage at the time of surgery. Intra-articular recordings were obtained during the operation in a standardized way. These recordings were obtained from 2 different hospitals in 2 countries by 3 different surgeons. Four fellowship-trained orthopaedic surgeons, with at least 2 years postfellowship experience in hip arthroscopy, independently analyzed the recordings 2 times in randomized order and 4 months apart. They classified the lesions according to the Outerbridge, Beck, and Haddad classifications of chondral damage. The values obtained were used for interobserver and intraobserver analysis. Percentage of agreement and weighted Cohen κ values were calculated. RESULTS: Absolute agreement between observers was present in 12.5% of the cases for the Outerbridge classification, in 20% of the cases for the Beck classification, and in 40% of the cases for the Haddad classification. For interobserver reliability, the average weighted Cohen κ values were 0.28 (95% confidence interval [CI], 0.16 to 0.39), 0.33 (95% CI, 0.24 to 0.41), and 0.47 (95% CI, 0.42 to 0.51) for the Outerbridge, Beck, and Haddad classification systems, respectively. For intraobserver reliability, the mean Cohen κ values were 0.62, 0.63, and 0.68 for the Outerbridge, Beck, and Haddad classification systems, respectively. CONCLUSIONS: In our series, the Haddad classification had the best interobserver reliability. There was no difference in the intraobserver reliability among the 3 classifications studied. LEVEL OF EVIDENCE: Level III, diagnostic study of nonconsecutive patients (without consistently applied reference gold standard).

Successful treatment of isolated, partial thickness ligamentum teres (LT) tears with debridement and capsulorrhaphy.

BACKGROUND: To determine if the addition of anterior capsular tightening to the treatment of partial ligamentum teres (LT) tears by debridement will diminish the recurrence rate of symptoms due to LT retears. METHOD: A prospective case series, including all patients treated for an isolated LT tear from June 2009 to August 2011. Arthroscopically the tear was debrided using radiofrequency (RF) and the joint capsule was tightened using either RF or suture plication. All the patients were prospectively assessed with the Modified Harris Hip Score (MHHS) and the Non Arthritic Hip Score (NAHS). A total of 1574 hip arthroscopies were performed from June 2009 to November 2011. Isolated partial LT tears, were found in 27 hips (26 patients). The average age was 24.4 years (range 12-45). There were 24 females and two males. RESULTS: Over an average follow-up period of 32 months (range 23-49), MHHS and NAHS preoperative outcome scores improved significantly. No revision surgery was required for a recurrent tear. CONCLUSION: Debridement of partial thickness LT tears, with additional anterior capsule tightening, has been shown to lead to improvents in MHHS and NAHS, with no recurrence of symptoms due to LT retear in the short to medium term.

Return to sport in Australian football league footballers after hip arthroscopy and midterm outcome.

PURPOSE: To study the return to sport in a series of professional athletes in a single sport (Australian Rules Football), operated on arthroscopically for hip joint pathology. METHODS: We performed a retrospective review of the senior author's surgical database starting in 2003. All of the patients who were Australian Football League (AFL) professional players with a minimum of 2 years' follow-up were included. Intra-articular pathologies were identified and treated. All patients were prospectively assessed with the modified Harris Hip Score (MHHS) and the Non-Arthritic Hip Score (NAHS). In addition, information about the active participation of the patients in their teams and return to professional sport was obtained from AFL registers and team physicians. RESULTS: Since 2003, the senior author has operated on 36 male professional AFL players; 26 of 27 with at least 2 years' follow-up were available for review. The mean age at the time of surgery was 22.1 years (range, 16 to 30 years), and 8 patients had bilateral pathology; therefore 34 hips were operated on. This report refers to those 26 players and 34 hips. All but 1 of the patients returned to play professionally. By the last survey (October 2011), 16 patients (62%) were still playing professional AFL football, and they have been playing for a mean of 52.5 months after surgery. Ten patients had retired from professional football, but they had all returned to play professionally after surgery. Only one of them retired for causes related to hip disability. There was a significant improvement in preoperative outcome scores. The MHHS and NAHS improved from 83.6 to 98 and from 85.3 to 97.1, respectively, in the players who were still playing (P < .05). Rim lesions were present in 33 hips (97%). Femoral osteochondroplasty was performed in 26 hips (76%). CONCLUSIONS: Arthroscopic treatment of intra-articular pathologies in professional athletes resulted in a 96% rate of return to elite-level sport and a durable increase in the MHHS and NAHS. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Arthroscopic ligamentum teres reconstruction using semitendinosus tendon: surgical technique and an unusual outcome.

Although the exact biomechanical function of the ligamentum teres (LT) remains unclear, an important role in hip stability has been suggested. In some patients, perhaps because of their specific anatomy or physical activity, it seems to have a major function as a hip stabilizer. Therefore, after a complete LT tear, this group of patients may have persistent hip pain and mechanical symptoms probably related to microinstability and subtle subluxation. We present the case of a female patient with a complete LT tear. This had been treated by debridement and anterior capsule tightening, followed by prolonged rehabilitation. However, she had persistent symptoms. An LT reconstruction with a novel surgical technique was performed. The LT was reconstructed with double-stranded semitendinosus graft. The acetabular end was fixed with 2 anchors, and the femoral end was passed into a bone tunnel and fixed with an interference screw. After surgery, the patient's modified Harris Hip Score and Non-Arthritic Hip Score improved from 53 and 73 to 100 and 95, respectively, at 12 months of follow-up. At repeat arthroscopy 15 months after surgery, it was observed that the graft had resorbed, although the 2 Ticron stitches (Covidien, Mansfield, MA) remained firmly attached and were still acting as a small synthetic ligament.