A Convergent Tibial Tunnel Technique for Concomitant Anterior Cruciate Ligament Reconstruction and Meniscal Root Repair.

Modern arthroscopic knee-reconstruction techniques involve the use of multiple bone tunnels and fixation devices to restore the anatomy and stability of the knee after traumatic injury. In these injuries, however, tunnel collision can be problematic, especially when combining anterior cruciate ligament reconstruction with meniscal root repairs or multiligament reconstructions. We describe a multiple tibial tunnel technique to allow fixation of both anterior cruciate ligament graft and meniscal roots through convergence to a single tibial cortical aperture.

The use of slice encoding for metal artifact correction (SEMAC) sequencing improves the diagnostic evaluation of graft integrity following anterior cruciate ligament reconstruction.

OBJECTIVES: To determine whether magnetic resonance imaging (MRI) with metal artifact reduction sequencing is superior to conventional knee MRI in the evaluation of an injured anterior cruciate ligament (ACL) graft, where visualisation on conventional MRI can be limited by the metal artifact from fixation devices. METHODS: Eighteen patients underwent conventional MRI sequence (proton density fat saturated [PDFS]) and two types of metal artifact reduction sequencing MRI (WARP, slice encoding for metal artifact correction (SEMAC); Siemens) following a secondary injury to their ACL reconstructed knee. Six raters with experience in knee MRI evaluation reviewed sagittal PDFS, WARP, and SEMAC sequences, providing semi-quantitative grades for visualisation and diagnostic confidence assessing the ACL, posterior cruciate ligament , menisci, tibial and femoral tunnel margins, and articular cartilage. Intra-class correlation coefficients for inter-rater reliability were evaluated. The 6-rater mean scores for the visualisation and diagnostic confidence derived from each sequence were compared using the Friedman test for multiple paired samples. RESULTS: No statistically significant difference in the ACL visualisation among the sequences was found (p â€‹= â€‹0.193). Further, a subgroup analysis was performed in cases evaluated as "moderately blurry" or "indistinct ACL visualisation" on PDFS (58% of cases). SEMAC significantly improved diagnostic confidence in ACL visualisation (p â€‹= â€‹0.041) and ACL graft rupture (p â€‹= â€‹0.044) compared to PDFS. There was no statistically significant difference in the inter-observer reliability between sequences. The WARP sequence added 2.84 â€‹± â€‹0.69 â€‹min, while SEMAC added 2.95 â€‹± â€‹0.40 â€‹min to the standard knee MRI scan time. CONCLUSION: use of the SEMAC metal reduction sequence significantly improved diagnostic accuracy and confidence in the detection of ACL graft rupture in cases where the ACL was moderately blurry or indistinct on the PDFS sequence. This sequence should be considered as an adjunct to conventional PDFS in cases where graft visualisation is limited by the metal artifact from fixation devices. LEVEL OF EVIDENCE: III.

Biomechanical Strength of All-Inside ACL Reconstruction Grafts Using Side-to-Side and Backup Fixation.

BACKGROUND: The all-inside anterior cruciate ligament reconstruction (ACLR) procedure uses a single hamstring tendon folded twice and secured to itself to form a 4-stranded graft. There are several possible configurations for preparing the graft. PURPOSE: To investigate the biomechanical properties of a new graft preparation technique in comparison with 2 commonly used configurations. STUDY DESIGN: Controlled laboratory study. METHODS: Five porcine flexor tendons were prepared into the test graft configuration: side-to-side fixation with a backup fixation at the button loop (graft M). The test configuration was compared with the results of a previous study that included grafts with simple interrupted sutures (graft A; n = 5) and end-to-end fixation (graft C; n = 5). All grafts were subjected to the same mechanical testing protocol to determine the mean failure load, stiffness, rate of elongation, and total elongation during both cyclic loading and pull to failure. Differences between groups were evaluated. RESULTS: Graft A had a significantly lower failure load (637 ± 99 N) compared with graft M (883 ± 66 N; P = .002) and graft C (846 ± 26 N; P = .002). Graft A also had significantly lower stiffness (166 ± 12 N/mm) compared with graft M (215 ± 8 N/mm; P < .001) and graft C (212 ± 11 N/mm; P < .001). Graft C had a significantly lower elongation during cyclic loading (3.42 ± 0.24 mm) compared with graft M (4.37 ± 0.74 mm; P = .026) and graft A (4.90 ± 0.88 mm; P = .006). The unsecured fixation was the weakest graft, with the lowest failure load and stiffness. The new side-to-side configuration and end-to-end configuration were equally strong. CONCLUSION: The new side-to-side configuration was not biomechanically superior to the end-to-end configuration; however, they were both stronger than unsecured fixation. CLINICAL RELEVANCE: As the all-inside ACLR is gaining popularity, this study provides surgeons with a new method of preparing grafts and evaluates the method with respect to currently used configurations.

Biomechanical Comparison of Graft Preparation Techniques for All-Inside Anterior Cruciate Ligament Reconstruction.

BACKGROUND: All-inside anterior cruciate ligament reconstruction (ACLR) is an emerging technique used to treat ACL injuries. The all-inside technique uses a 4-stranded graft made from a single tendon that is looped on itself. The 4 strands of the graft must be secured to each other to become a closed-loop structure. Various suture configurations exist to secure the graft to adjustable loop devices, and there is a lack of data to support one technique over another. In addition to the primary sutures used to fasten the graft together, accessory sutures can be tied over the button as secondary fixation. PURPOSE: To evaluate biomechanical properties of 4-stranded grafts prepared in 5 different configurations. STUDY DESIGN: Controlled laboratory study. METHODS: Porcine flexor tendons (N = 25) were prepared in 5 different configurations (n = 5 tendons per group): simple-interrupted sutures (unsecured fixation), side-to-side fixation with and without secondary fixation, and end-to-end fixation with and without secondary fixation. The grafts were put through the same mechanical testing protocol (cyclic loading, pull to failure) to measure average load at graft failure, average displacement at failure, average stiffness, and average elongation rate. Differences between graft preparation techniques were investigated using 1-way analyses of variance (ANOVAs) with post hoc t tests (P < .05). RESULTS: Significant 1-way ANOVAs for each biomechanical property were found. Unsecured fixation was the weakest graft preparation with the lowest stiffness (167 ± 12 N/mm), lowest ultimate failure load (637 ± 99 N), and highest elongation rate (0.0033 ± 0.0007 mm/s). End-to-end fixation without secondary fixation showed the highest ultimate failure load (846 ± 26 N), highest stiffness (212 ± 10 N/mm), and lowest rate of elongation (0.0025 ± 0.0001 mm/s). End-to-end fixation, both with and without secondary fixation, as well as side-to-side fixation with secondary fixation showed significantly higher ultimate failure loads than grafts with unsecured fixation. End-to-end fixation performed better than side-to-side fixation; however, for most variables, the difference was not statistically significant. Secondary fixation did not provide significant improvement. CONCLUSION: The all-inside ACL graft with simple-interrupted sutures is biomechanically inferior to a graft that has its free ends secured to the adjustable tibial loop. Adding secondary fixation to the tibial button does not significantly change the biomechanical properties. Further clinical studies are required to determine whether these findings translate into differences in clinical outcome. CLINICAL RELEVANCE: All-inside ACLR is gaining popularity in hamstring ACL reconstructive techniques. These results provide surgeons with guidance on the best graft preparation method when using a single quadrupled hamstring tendon graft.

Towards improving the identification of anterior cruciate ligament tears in primary point-of-care settings.

BACKGROUND: Only a small proportion of anterior cruciate ligament (ACL) tears are diagnosed on initial healthcare consultation. Current clinical guidelines do not acknowledge that primary point-of-care practitioners rely more heavily on a clinical history than special clinical tests for diagnosis of an ACL tear. This research will assess the accuracy of combinations of patient-reported variables alone, and in combination with clinician-generated variables to identify an ACL tear as a preliminary step to designing a primary point-of-care clinical decision support tool. METHODS: Electronic medical records (EMRs) of individuals aged 15-45 years, with ICD-9 codes corresponding to a knee condition, and confirmed (ACL+) or denied (ACL-) first-time ACL tear seen at a University-based Clinic between 2014 and 2016 were eligible for inclusion. Demographics, relevant diagnostic indicators and ACL status based on orthopaedic surgeon assessment and/or MRI reports were manually extracted. Descriptive statistics calculated for all variables by ACL status. Univariate between group comparisons, clinician surveys (n = 17), availability of data and univariable logistic regression (95%CI) were used to select variables for inclusion into multivariable logistic regression models that assessed the odds (95%CI) of an ACL-tear based on patient-reported variables alone (consistent with primary point-of-care practice), or in combination with clinician-generated variables. Model performance was assessed by accuracy, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios (95%CI). RESULTS: Of 1512 potentially relevant EMRs, 725 were included. Participant median age was 26 years (range 15-45), 48% were female and 60% had an ACL tear. A combination of patient-reported (age, sport-related injury, immediate swelling, family history of ACL tear) and clinician-generated (Lachman test result) variables were superior for ACL tear diagnosis [accuracy; 0.95 (90,98), sensitivity; 0.97 (0.88,0.98), specificity; 0.95 (0.82,0.99)] compared to the patient-reported variables alone [accuracy; 84% (77,89), sensitivity; 0.60 (0.44,0.74), specificity; 0.95 (0.89,0.98)]. CONCLUSIONS: A high proportion of individuals without an ACL tear can be accurately identified by considering patient-reported age, injury setting, immediate swelling and family history of ACL tear. These findings directly inform the development of a clinical decision support tool to facilitate timely and accurate ACL tear diagnosis in primary care settings.

Contribution of Fc-dependent cell-mediated activity of a vestigial esterase-targeting antibody against H5N6 virus infection.

The highly pathogenic avian influenza A (H5N6) virus has caused sporadic human infections with a high case fatality rate. Due to the continuous evolution of this virus subtype and its ability to transmit to humans, there is an urgent need to develop effective antiviral therapeutics. In this study, a murine monoclonal antibody 9F4 was shown to display broad binding affinity against H5Nx viruses. Furthermore, 9F4 can neutralize H5N6 pseudotyped particles and prevent entry into host cells. Additionally, ADCC/ADCP deficient L234A, L235A (LALA) and CDC deficient K322A mutants were generated and displayed comparable binding affinity and neutralizing activity as wild type 9F4 (9F4-WT). Notably, 9F4-WT, 9F4-LALA and 9F4-K322A exhibit in vivo protective efficacies against H5N6 infections in that they were able to reduce viral loads in mice. However, only 9F4-WT and 9F4-K322A but not 9F4-LALA were able to reduce viral pathogenesis in H5N6 challenged mice. Furthermore, depletion of phagocytic cells in mice lungs nullifies 9F4-WT's protection against H5N6 infections, suggesting a crucial role of the host's immune cells in 9F4 antiviral activity. Collectively, these findings reveal the importance of ADCC/ADCP function for 9F4-WT protection against HPAIV H5N6 and demonstrate the potential of 9F4 to confer protection against the reassortant H5-subtype HPAIVs.

Analysis of a fully infectious bio-orthogonally modified human virus reveals novel features of virus cell entry.

We report the analysis of a complex enveloped human virus, herpes simplex virus (HSV), assembled after in vivo incorporation of bio-orthogonal methionine analogues homopropargylglycine (HPG) or azidohomoalanine (AHA). We optimised protocols for the production of virions incorporating AHA (termed HSVAHA), identifying conditions which resulted in normal yields of HSV and normal particle/pfu ratios. Moreover we show that essentially every single HSVAHA capsid-containing particle was detectable at the individual particle level by chemical ligation of azide-linked fluorochromes to AHA-containing structural proteins. This was a completely specific chemical ligation, with no capsids assembled under normal methionine-containing conditions detected in parallel. We demonstrate by quantitative mass spectrometric analysis that HSVAHA virions exhibit no qualitative or quantitative differences in the repertoires of structural proteins compared to virions assembled under normal conditions. Individual proteins and AHA incorporation sites were identified in capsid, tegument and envelope compartments, including major essential structural proteins. Finally we reveal novel aspects of entry pathways using HSVAHA and chemical fluorochrome ligation that were not apparent from conventional immunofluorescence. Since ligation targets total AHA-containing protein and peptides, our results demonstrate the presence of abundant AHA-labelled products in cytoplasmic macrodomains and tubules which no longer contain intact particles detectable by immunofluorescence. Although these do not co-localise with lysosomal markers, we propose they may represent sites of proteolytic virion processing. Analysis of HSVAHA also enabled the discrimination from primary entering from secondary assembling virions, demonstrating assembly and second round infection within 6 hrs of initial infection and dual infections of primary and secondary virus in spatially restricted cytoplasmic areas of the same cell. Together with other demonstrated applications e.g., in genome biology, lipid and protein trafficking, this work further exemplifies the utility and potential of bio-orthogonal chemistry for studies in many aspects of virus-host interactions.

A NS1-binding monoclonal antibody interacts with two residues that are highly conserved in seasonal as well as newly emerged influenza A virus.

The non-structural protein 1 (NS1) of influenza A virus (IAV) is a multifunctional protein that antagonizes host antiviral responses, modulating virus pathogenesis. As such, it serves as a good target for research and diagnostic assay development. In this study, we have generated a novel monoclonal antibody (mAb) 19H9 and epitope mapping revealed that two residues, P85 and Y89, of NS1 are essential for interacting with this mAb. Furthermore, residues P85 and Y89 are found to be highly conserved across different IAV subtypes, namely seasonal H1N1 and H3N2, as well as the highly pathogenic H5N1 and H5N6 avian strains. Indeed, mAb 19H9 exhibits broad cross-reactivity with IAV strains of different subtypes. The binding of mAb 19H9 to residue Y89 was further confirmed by the abrogation of interaction between NS1 and p85ß. Additionally, mAb 19H9 also detected NS1 proteins expressed in IAV-infected cells, showing NS1 intracellular localization in the cytoplasm and nucleolus. To our knowledge, mAb 19H9 is the first murine mAb to bind at the juxtaposition between the N-terminal RNA-binding domain and C-terminal effector domain of NS1. It could serve as a useful research tool for studying the conformational plasticity and dynamic changes in NS1.

An unusual case of Erysipelothrix rhusiopathiae prosthetic joint infection from the Canadian Arctic: whole genome sequencing unable to identify a zoonotic source.

BACKGROUND: Erysipelothrix rhusiopathiae is a zoonotic pathogen that causes erysipeloid and is most frequently associated with exposure to domestic swine. Infection of native and prosthetic joints is a rarely reported manifestation. CASE PRESENTATION: We describe a case of E. rhusiopathiae prosthetic joint infection in a woman with a history of exposure to wild animals in the Canadian Arctic. Patient management involved a 1-stage surgical revision exchange with an antibiotic impregnated cement spacer and 6 weeks of intravenous penicillin G followed by 6 weeks of oral amoxicillin. Ten previously reported cases of E. rhusiopathiae joint infection are reviewed. Recent increases in mortality due to infection with this organism among host animal populations in the Canadian Arctic have generated concern regarding a potential increase in human infections. However, whole genome sequencing (WGS) of the organism was unable to identify a zoonotic origin for this case. CONCLUSIONS: Consideration should be given to E. rhusiopathiae as a cause of joint infections if the appropriate epidemiologic and host risk factors exist. Expanded use of WGS in other potential animal hosts and environmental sources may provide important epidemiologic information in determining the source of human infections.

Recurrent Instability Episodes and Meniscal or Cartilage Damage After Anterior Cruciate Ligament Injury: A Systematic Review.

BACKGROUND: Delayed anterior cruciate ligament (ACL) reconstruction may be associated with increased risk of subsequent knee joint damage and osteoarthritis (OA). The relationship between recurrent instability episodes and meniscal or cartilage damage after first-time ACL injury is unknown. PURPOSE: To assess the association between recurrent knee instability episodes and prevalence of meniscal lesions, cartilage damage, and OA after first-time ACL injury. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: Six electronic databases were systematically searched using keywords and Medical Subject Heading terms. Studies selected were of English language, included original data, had a prospective design, and provided an outcome of recurrent instability and meniscal lesions, cartilage damage, or OA after first-time ACL injury. Adjusted odds ratios (ORs) were extracted or unadjusted ORs (95% CI) were calculated. PRISMA guidelines were followed, and 2 independent raters assessed study quality using Downs and Black criteria. RESULTS: Of 905 potentially relevant studies, 7 were included. Sample sizes ranged from 43 to 541, and Downs and Black scores ranged from 2 to 12. Clinical and methodological heterogeneity precluded meta-analysis. Six studies reported a positive association between recurrent instability episodes and medial meniscal damage (OR range, 3.46 [95% CI, 1.24-9.99] to 11.56 [1.37-521.06]). The association between instability episodes and lateral meniscal or cartilage damage was inconsistent. No studies examined the association between instability episodes and OA. CONCLUSION: This systematic review provides preliminary evidence that recurrent instability episodes after first-time ACL injury may be associated with increased odds of medial meniscal damage. This highlights the importance of early diagnosis, education, and treatment for individuals with ACL injury, all of which must include a specific focus on the prevention and management of instability episodes. High-quality, prospective cohort studies are needed that assess the effects of diagnostic and treatment delay, recurrent instability episodes on secondary meniscal and cartilage damage, and OA after an initial ACL injury.

A Validation Study of a Novel 3-Dimensional MRI Modeling Technique to Identify the Anatomic Insertions of the Anterior Cruciate Ligament.

BACKGROUND: Anatomic single bundle anterior cruciate ligament (ACL) reconstruction is the current gold standard in ACL reconstructive surgery. However, placement of femoral and tibial tunnels at the anatomic center of the ACL insertion sites can be difficult intraoperatively. We developed a "virtual arthroscopy" program that allows users to identify ACL insertions on preoperative knee magnetic resonance images (MRIs) and generates a 3-dimensional (3D) bone model that matches the arthroscopic view to help guide intraoperative tunnel placement. PURPOSE: To test the validity of the ACL insertion sites identified using our 3D modeling program and to determine the accuracy of arthroscopic ACL reconstruction guided by our "virtual arthroscopic" model. STUDY DESIGN: Descriptive laboratory study. METHODS: Sixteen cadaveric knees were prescanned using routine MRI sequences. A trained, blinded observer then identified the center of the ACL insertions using our program. Eight knees were dissected, and the centers of the ACL footprints were marked with a screw. In the remaining 8 knees, arthroscopic ACL tunnels were drilled into the center of the ACL footprints based on landmarks identified using our virtual arthroscopic model. Postprocedural MRI was performed on all 16 knees. The 3D distance between pre- and postoperative 3D centers of the ACL were calculated by 2 trained, blinded observers and a musculoskeletal radiologist. RESULTS: With 2 outliers removed, the postoperative femoral and tibial tunnel placements in the open specimens differed by 2.5 ± 0.9 mm and 2.9 ± 0.7 mm from preoperative centers identified on MRI. Postoperative femoral and tibial tunnel centers in the arthroscopic specimens differed by 3.2 ± 0.9 mm and 2.9 ± 0.7 mm, respectively. CONCLUSION: Our results show that MRI-based 3D localization of the ACL and our virtual arthroscopic modeling program is feasible and does not show a statistically significant difference to an open arthrotomy approach. However, additional refinements will be required to improve the accuracy and consistency of our model to make this an effective tool for surgeons performing anatomic single-bundle ACL reconstructions. CLINICAL RELEVANCE: Arthroscopic anatomic single-bundle ACL reconstruction is the current gold standard for ACL reconstruction; however, the center of the ACL footprint can be difficult to identify arthroscopically. Our novel modeling can improve the identification of this important landmark intraoperatively and decrease the risk of graft malposition and subsequent graft failure.

Five-year changes in gait biomechanics after concomitant high tibial osteotomy and ACL reconstruction in patients with medial knee osteoarthritis.

BACKGROUND: Concomitant high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction is a combined surgical procedure intended to improve kinematics and kinetics in the unstable ACL-deficient knee with varus malalignment and medial compartment knee osteoarthritis (OA). PURPOSE: To investigate 5-year changes in gait biomechanics as well as radiographic and patient-reported outcomes bilaterally after unilateral, concomitant medial opening wedge HTO and ACL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 33 patients (mean ± SD age, 40 ± 9 years) with varus malalignment (mean mechanical axis angle, -5.9° ± 2.9°), medial compartment knee OA, and ACL deficiency completed 3-dimensional gait analysis preoperatively and 2 and 5 years postoperatively. Primary outcomes were the peak external knee adduction (first peak) and flexion moments. Secondary outcomes were the peak external knee extension and transverse plane moments, peak knee angles in all 3 planes, radiographic static knee alignment measures (mechanical axis angle and posterior tibial slope), and the Knee injury and Osteoarthritis Outcome Score (KOOS). RESULTS: There was a substantial decrease in the knee adduction moment in the surgical limb (%BW × H, -1.49; 95% CI, -1.75 to -1.22) and a slight increase in the nonsurgical limb (%BW × H, 0.16; 95% CI, 0.03 to 0.30) from preoperatively to 5 years postoperatively. There was also a decrease in the knee flexion moment for both the surgical (%BW × H, -0.67; 95% CI, -1.19 to -0.15) and nonsurgical limbs (%BW × H, -1.06; 95% CI, -1.49 to -0.64). Secondary outcomes suggested that substantial improvements were maintained at 5 years, although smaller declines were observed in several measures and in both limbs from 2 to 5 years. CONCLUSION: Changes in the peak external moments about the knee in all 3 planes during walking were observed 5 years after concomitant medial opening wedge HTO and ACL reconstruction. These findings are consistent with an intended, sustained shift in the mediolateral distribution of knee loads. CLINICAL RELEVANCE: These findings suggest that concomitant HTO and ACL reconstruction results in substantial changes in gait biomechanics. Future clinical research comparing treatment strategies is both warranted and required for this relatively uncommon but seemingly biomechanically efficacious procedure.

Reliability of 3D localisation of ACL attachments on MRI: comparison using multi-planar 2D versus high-resolution 3D base sequences.

PURPOSE: Anatomic placement of anterior cruciate ligament (ACL) grafts at arthroscopic reconstruction can be challenging. Localising ACL attachments on magnetic resonance imaging (MRI) sequences pre-operatively could aid with planning for anatomic graft placement. Though ACL attachments can be identified on two-dimensional (2D) MRI, slice thickness theoretically limits out-of-plane accuracy and a 3D MRI base sequence with smaller isotropic voxels may improve observer reliability in localising ACL attachment locations. The purpose of this study was to test whether a high-resolution 3D sequence improved inter- and intra-observer reliability of ACL attachment localisation compared with conventional 2D MRI for this application. METHODS: Twenty paediatric knees were retrospectively scanned at 1.5 Tesla with multi-planar 2D proton density (slice thickness 3-4 mm) and T2-weighted 3D multiple-echo data image combination gradient echo (isotropic 0.8 mm voxels) sequences. Two observers blinded to each others' findings identified ACL attachments on MRI slices, and 3D reconstructions showing ACL attachments were produced. ACL attachment centre locations and areas were calculated, and reliability assessed. RESULTS: Inter-observer variation of centre locations of ACL attachments identified on 3D versus 2D sequences was not significantly different (mean ± SD): 1.8 ± 0.6 versus 1.5 ± 0.7 mm at femoral attachments, 1.7 ± 0.7 versus 1.5 ± 0.8 mm at tibial attachments (p > 0.05). The 95 % confidence interval for centre locations was <4.0 mm in all cases. Inter-observer reliability of attachment areas was not higher for 3D sequences. CONCLUSIONS: ACL attachment centres were localised with high and similar inter- and intra-observer reliability on a high-resolution 3D and multi-planar conventional 2D sequences. Using this technique, MRI could potentially be used for planning and intra-operative guidance of anatomic ACL reconstruction, whether from 2D or 3D base sequences. Surgeons in clinical practice need not order a lengthy dedicated 3D MRI to localise ligament attachments, but can confidently use a standard 2D MRI for this application. LEVEL OF EVIDENCE: III.

Comparison of cast materials for the treatment of congenital idiopathic clubfoot using the Ponseti method: a prospective randomized controlled trial.

BACKGROUND: The Ponseti method of congenital idiopathic clubfoot correction has traditionally specified plaster of Paris (POP) as the cast material of choice; however, there are negative aspects to using POP. We sought to determine the influence of cast material (POP v. semirigid fibreglass [SRF]) on clubfoot correction using the Ponseti method. METHODS: Patients were randomized to POP or SRF before undergoing the Ponseti method. The primary outcome measure was the number of casts required for clubfoot correction. Secondary outcome measures included the number of casts by severity, ease of cast removal, need for Achilles tenotomy, brace compliance, deformity relapse, need for repeat casting and need for ancillary surgical procedures. RESULTS: We enrolled 30 patients: 12 randomized to POP and 18 to SRF. There was no difference in the number of casts required for clubfoot correction between the groups (p = 0.13). According to parents, removal of POP was more difficult (p < 0.001), more time consuming (p < 0.001) and required more than 1 method (p < 0.001). At a final follow-up of 30.8 months, the mean times to deformity relapse requiring repeat casting, surgery or both were 18.7 and 16.4 months for the SRF and POP groups, respectively. CONCLUSION: There was no significant difference in the number of casts required for correction of clubfoot between the 2 materials, but SRF resulted in a more favourable parental experience, which cannot be ignored as it may have a positive impact on psychological well-being despite the increased cost associated.

CONTEXTE: La méthode de Ponseti pour la correction du pied bot congénital idiopathique a de tout temps spécifié l'utilisation du plâtre de Paris comme matériau de choix; il y a toutefois certains inconvénients associés au plâtre de Paris. Nous avons voulu déterminer l'influence du matériau utilisé (plâtre de Paris c. fibre de verre semi-rigide) sur la correction du pied bot selon la méthode de Ponseti. MÉTHODES: Les patients ont été assignés aléatoirement soit au plâtre de Paris soit à la fibre de verre semi-rigide en vue de l'intervention de Ponseti. Le principal paramètre mesuré était le nombre de plâtres requis pour corriger le pied bot. Les paramètres secondaires incluaient le nombre de plâtres en fonction de la gravité, la facilité de retrait du plâtre, la nécessité de sectionner le tendon d'Achille, le port assidu de l'attelle, le retour de la difformité, la nécessité d'autres plâtres et interventions chirurgicales auxiliaires. RÉSULTATS: Nous avons inscrit 30 patients : 12 ont été assignés au plâtre de Paris et 18 à la fibre de verre. On n'a noté aucune différence entre les groupes quant au nombre de plâtres requis pour la correction du pied bot (p = 0,13). Selon les parents, le retrait du plâtre de Paris était plus difficile p < 0,001), prenait plus de temps (p < 0,001) et nécessitait le recours à plus d'une méthode (p < 0,001). Au moment du dernier suivi à 30,8 mois, les intervalles moyens avant un retour de la difformité nécessitant la pose d'un autre plâtre et/ou une chirurgie ont été de 18,7 et 16,4 mois dans les groupes traités au moyen de la fibre de verre semi-rigide et du plâtre de Paris, respectivement.. CONCLUSION: On n'a noté aucune différence significative entre les 2 matériaux quant au nombre de plâtres requis pour corriger le pied bot, mais la fibre de verre a donné lieu à une expérience plus agréable pour les parents, ce qui ne peut être ignoré en raison de l'impact potentiellement positif sur le bien-être psychologique, et ce, malgré un coût plus élevé.

MRI Anatomy of the Tibial ACL Attachment and Proximal Epiphysis in a Large Population of Skeletally Immature Knees: Reference Parameters for Planning Anatomic Physeal-Sparing ACL Reconstruction.

BACKGROUND: To aid in performing anatomic physeal-sparing anterior cruciate ligament (ACL) reconstruction, it is important for surgeons to have reference data for the native ACL attachment positions and epiphyseal anatomy in skeletally immature knees. PURPOSE: To characterize anatomic parameters of the ACL tibial insertion and proximal tibial epiphysis at magnetic resonance imaging (MRI) in a large population of skeletally immature knees. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: The ACL tibial attachment site and proximal epiphysis were examined in 570 skeletally immature knees with an intact ACL (age, 6-15 years) using 1.5-T proton density-weighted sagittal MRI; also measured were the tibial anteroposterior diameter; anterior, central, and posterior ACL attachment positions; vertical height of the epiphysis; and maximum oblique epiphyseal depth extending from the ACL tibial attachment center to the tibial tuberosity. RESULTS: In adolescents (11-15 years of age), the center of the ACL's tibial attachment was 51.5% ± 5.7% of the anteroposterior diameter of the tibia, with no significant differences between sexes or age groups (P > .05 in all cases). Mean vertical epiphyseal height was 15.9 ± 1.7 mm in the adolescent group, with significant differences between 11-year-olds (15.2 ± 1.5 mm) and 15-year-olds (16.6 ± 1.6 mm), P < .001, and between males (16.6 ± 1.5 mm) and females (14.8 ± 1.4), P < .001. Mean maximum oblique depth was 30.0 ± 5.3 mm, with a significant difference between 11-year-olds (26.7 ± 4.9 mm) and 15-year-olds (32.7 ± 5.1 mm), P < .001, and between males (29.7 ± 6.4 mm) and females (27.8 ± 5.2 mm), P < .001. The maximum oblique depth occurred at a mean angle of ~50°, and this angle did not change with age or sex. There was a significant moderate correlation (r = 0.39, P < .001) between epiphyseal vertical height and maximum oblique depth. CONCLUSION: The center of the ACL tibial attachment was consistently near 51% of the anteroposterior diameter, regardless of age or sex. The vertical depth of the tibial epiphysis was ~16 mm in adolescents. Maximum oblique depth from ACL attachment was ~30 mm, occurring at a mean angle ~50° regardless of age or sex. The normative values for tibial ACL attachment and epiphyseal anatomy presented here may be helpful in selecting candidates for surgery and in planning surgical approaches for pediatric ACL reconstruction.

Three-dimensional intercondylar notch volumes in a skeletally immature pediatric population: a magnetic resonance imaging-based anatomic comparison of knees with torn and intact anterior cruciate ligaments.

PURPOSE: To determine whether 3-dimensional notch volume, measured with magnetic resonance imaging (MRI), differs significantly between knees with torn and intact anterior cruciate ligaments (ACLs) after sports injury in a skeletally immature pediatric population. METHODS: MRI studies of 50 pediatric patients (age range, 10 to 17 years) with ACL tears were compared with 50 age- and sex-matched intact-ACL control patients. All patients had open physes and underwent MRI after a sports injury. Notch volume was calculated through manual segmentation of notch boundaries seen on axial 1.5-T proton density-weighted images. Two-dimensional (2D) measurements (notch width and notch width index) were made on coronal proton density-weighted MRI studies. Notch volume was compared between groups by use of the Mann-Whitney U test. Pearson correlation coefficients were also calculated between indices. RESULTS: Notch volume was significantly lower in knees with ACL tears than in control knees (5.5 ± 1.1 cm(3)v 6.4 ± 1.5 cm(3), P = .002), whereas 2D notch width and notch width index did not differ significantly between these groups. Girls had significantly smaller notch volumes than boys (5.4 ± 1.2 cm(3)v 6.5 ± 1.3 cm(3), P < .001). Notch volume was not correlated with age but was moderately correlated with 2D notch width (r = 0.485, P < .001). CONCLUSIONS: In adolescent patients with sports injuries, the 3-dimensional notch volume was significantly smaller in knees with ACL tears than in intact-ACL control knees. Notch volume was also significantly smaller in girls than in boys and did not vary significantly with age. LEVEL OF EVIDENCE: Level III, case-control study.

Reliability of estimates of ACL attachment locations in 3-dimensional knee reconstruction based on routine clinical MRI in pediatric patients.

BACKGROUND: Current techniques of anterior cruciate ligament (ACL) reconstruction focus on the placement of femoral and tibial tunnels at anatomic ACL attachments, which can be difficult to identify intraoperatively. PURPOSE: To determine whether the 3-dimensional (3D) center of ACL attachments can be reliably detected from routine magnetic resonance imaging (MRI) in patients with intact ACLs and whether the reliability of this technique changes if the ACL is torn. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: A computer technique was developed in which users identify points along ACL attachments on routine clinical MRI of preoperative knees. These attachments are then displayed on a 3D MRI reconstruction, which can be used as a visual guide for the surgeon during arthroscopic surgery. Thirty-seven pediatric patients (age range, 10-17 years) with ACL tears and 37 controls with intact ACLs were examined. Two blinded observers identified cruciate ligament attachments on routine clinical 1.5-T MRI of knees. From the resulting 3D model, the location of the center of each ligament attachment site and its area were calculated and reliability assessed. RESULTS: Mean interobserver variation of the centers of ACL attachments for the intact versus torn ACL was 1.7 ± 0.9 mm versus 1.8 ± 1.1 mm (femoral) and 1.4 ± 0.9 mm versus 1.7 ± 1.0 mm (tibial), respectively (P > .05). The 95% confidence interval for the center location was at most 4 mm. The identified ACL attachment areas were more variable, with interobserver reliability ranging from fair to excellent by the intraclass correlation coefficient. Overlap of ligament areas between observers for the intact versus torn ACL was 70% ± 15% versus 73% ± 12% (femoral) and 79% ± 9% versus 78% ± 10% (tibial), respectively (P > .05). In all cases, intraobserver reliability was superior to interobserver reliability. CONCLUSION: The 3D locations of ACL tibial and femoral attachment centers were identified from routine clinical MRI with variability averaging less than 2 mm between 2 observers. The margin of error was at most 4 mm, representing the thickness of a single axial MRI slice, whether the ACL was intact or torn. Remnant tissue at attachments allows a reliable assessment even of torn ligaments. Identification of the ligament attachment areas was more user dependent than was identification of the attachment centers.

Outcome of anatomic transphyseal anterior cruciate ligament reconstruction in Tanner stage 1 and 2 patients with open physes.

BACKGROUND: Anterior cruciate ligament (ACL) injuries are being seen with increasing frequency in children. Treatment of the ACL-deficient knee in skeletally immature patients is controversial. PURPOSE: To determine the outcome of all-arthroscopic transphyseal anatomic single-bundle ACL reconstruction in Tanner stage 1 and 2 patients at a minimum of 2 years after surgery. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 2007 and 2008, 16 prepubescent patients underwent ACL reconstruction using soft tissue grafts. All patients were Tanner stage 1 and 2. Outcomes were assessed at a minimum of 2 years after surgery and included limb alignment, limb length, instrumented testing with the KT-1000 arthrometer, and International Knee Documentation Committee (IKDC) score. RESULTS: Mean age at the time of surgery was 12 years (range, 8-14 years). Graft choices included the following: living donor-related hamstring tendon allograft (n = 14), hamstring tendon autograft (n = 1), and fresh-frozen allograft (n = 1). Mean IKDC subjective score was 96 (range, 84-100). All patients had a stable knee postoperatively. Eleven patients had a negative Lachman test result, and 14 had a negative pivot-shift test result. The remainder had grade 1 Lachman and pivot-shift test findings, respectively. At 2 years after surgery, all patients had returned to strenuous activities, and normal or nearly normal overall IKDC score was documented in 94% of patients. There were no cases of limb malalignment or growth arrest. CONCLUSION: We present a case series of transphyseal anatomic single-bundle ACL reconstruction in Tanner stage 1 and 2 patients at a minimum of 2 years after surgery. Excellent clinical outcomes were obtained with high levels of return to desired activities. Importantly, no growth disturbances were seen in this series of patients.

Clinical and patient-reported outcomes of patients with four major lower extremity arthroplasties.

Few studies report the outcomes of patients treated with total joint arthroplasty of both hips and both knees. We present the outcomes of 14 patients with total joint arthroplasty of both hips and both knees using validated outcome measures. Eleven patients (79%) were satisfied at final review. Ten patients (71%) required revision surgery of at least one joint. Clinical, functional, radiographic, and patient-reported outcomes were consistent with previously reported outcomes in the literature. Mean Timed Up and Go test was 32 seconds (6-158). Mean Berg Balance Scale was 38.5 (4-55). Good outcomes can be achieved in this group of patients with high levels of satisfaction despite the frequent need for revision surgery. Importantly, it was recognized that these patients have a high risk of falls and must be educated in measures for fall prevention.

Five-year comparison of oxidized zirconium and cobalt-chromium femoral components in total knee arthroplasty: a randomized controlled trial.

BACKGROUND: In vitro analysis has shown that oxidized zirconium on ultra-high molecular weight polyethylene has better wear properties than cobalt-chromium on ultra-high molecular weight polyethylene. The purpose of this study was to determine if oxidized zirconium femoral components performed better than cobalt-chromium in vivo and if the use of oxidized zirconium components had clinical adverse effects. METHODS: Forty consecutive patients (eighty knees) underwent simultaneous bilateral cruciate-retaining total knee arthroplasty for primary osteoarthritis from January 2002 to December 2003. For each patient, the knees were randomized to receive the oxidized zirconium femoral component, with the contralateral knee receiving the cobalt-chromium component. Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index, Knee Injury and Osteoarthritis Outcome Score, Knee Society score, and British Orthopaedic Association patient satisfaction scale. Radiographic outcomes include the Knee Society total knee arthroplasty roentgenographic evaluation and scoring system and measurement of radiographic wear. Patients and assessors were blinded to the treatment groups and results. RESULTS: There were no significant differences in clinical, subjective, and radiographic outcomes between the two implants at five days, six weeks, and one, two, or five years postoperatively. At five years following surgery, 38% of the patients preferred the cobalt-chromium knee compared with 18% who preferred the oxidized zirconium knee (p = 0.02) and 44% had no preference. CONCLUSIONS: Five-year outcomes after total knee arthroplasty with oxidized zirconium and cobalt-chromium femoral components showed no significant differences in clinical, subjective, and radiographic outcomes. Patients had no preference or preferred the cobalt-chromium prosthesis to the oxidized zirconium prosthesis at the time of the five-year follow-up. There were no adverse effects associated with the use of oxidized zirconium femoral implants.