Nicolas Reina

Experimental study of an original radiographic view for diagnosis of cam-type anterior femoroacetabular impingement

PurposePrimary paraclinical investigation to look for femoral morphological abnormality consistent with cam-type anterior femoroacetabular impingement (FAI) must include specific radiographic projections of the hip from the following: cross-table, frog-leg or Dunn (90° and 45° flexion). We use a frog-leg type view with fixed angles as described by Chiron, obtained with the patient in a supine position, with the hip in 45° flexion-abduction and 30° external rotation. The X-ray beam is anteroposterior and centred on the femoral head. We evaluated this view by comparing it with other views in common use.MethodsIn this experimental study, we created artificial radio-opaque morphological abnormalities secured onto normal femoral necks. The femurs were placed in relation to a fixed pelvis using orthogonal landmarks, in the positions of the various radiographic views. The digital radiographs were analysed by two observers. Nineteen femurs were included to reveal a difference of 5° between the alpha angle of Nötzli et al. [11] measured on the Dunn view and the frog-leg 45/45/30 view (Student’s paired test).ResultsThe highest mean values of the alpha angle of Nötzli were always obtained with the frog-leg 45/45/30 view (87.4°, 86.2°, 84.5°) and the lowest with the cross-table view. We found a mean difference of 8.95° with the 90° Dunn view (P = 0.00007), 3.44° with the 45° Dunn view (P = 0.004) and 13.47° with the cross-table view (P = 0.002).ConclusionsThis experimental study confirmed the value of the frog-leg 45/45/30 view in assisting diagnosis of cam-type FAI.

Anatomy of the bands of the hamstring tendon: How can we improve harvest quality?

BACKGROUND The hamstring tendons, gracilis and semitendinosus are widely used in ligament and reconstructive surgery. Their accessory bands or insertions are technical pitfalls during harvesting. METHODS Thirty fresh cadaver knees have been studied, in order to 1) determine the anatomy of the bands of the gracilis and semitendinosus tendons, and, 2) to identify risk factors for failure during harvesting. RESULTS Semitendinosus always had at least one band, sometimes two, strong, tendinous, and generally running to the fascia of gastrocnemius medialis to which they are attached, at an acute angle in a distal direction. Their presence is constant and they are only exceptionally found more than 100 mm from the tendons tibial insertion. Gracilis shows the greatest anatomical variability, and over one quarter have no bands (although there may be as many as three). Their location, destination and angle of attachment to the tendon vary greatly. These bands are mainly aponeurotic and less strong, but must be carefully and widely dissected. CONCLUSION Anatomical variability makes harvesting of pes anserinus tendons difficult. Three simple anatomical criteria have been highlighted that can be assessed by the surgeon during harvesting. The criteria are the insertion, the direction and the anatomical type of the bands.

Obesity is no longer a risk factor for dislocation after total hip arthroplasty with a double-mobility cup

PurposeDislocation is one of the most feared complications after total hip arthroplasty (THA). This risk is greater in obese patients compared with the general population.MethodsWe performed a retrospective cohort study in which the main objective was to compare the dislocation rate between obese patients (BMI > 30 kg/m²) (exposed group) and non-obese patients (BMI ≤ 30 kg/m²) (unexposed group) after primary THA with a double-mobility acetabular cup. The patients had a minimum follow-up of 24 months.ResultsThe ‘obese’ group consisted of 77 THA cases and the ‘non-obese’ group of 425 cases; the two groups were similar in terms of age, gender and ASA score. After a mean follow-up of 58.3 ± 27 months (range 27–159), 43 patients had been lost to follow-up and 56 had died; the two groups had similar mean values. One patient in the ‘obese’ group had suffered a dislocation due to a fall 16 months after the THA. One patient in the ‘non-obese’ group had suffered a dislocation after a periprosthetic femur fracture with stem subsidence two months after the THA procedure. Both patients underwent surgical revision where the double-mobility cup was preserved; there were no further dislocation events as of the last follow-up. The dislocation rate in the two groups was similar (1.3 % versus 0.23 %, p > 0.05). No cases of loosening were found. Revisions were secondary to deep or superficial infection (n = 22), periprosthetic femur fracture (n = 10) or haematoma (n = 3).ConclusionThese findings imply that double-mobility cups are a reliable way of reducing the risk of dislocation in obese patients after primary THA.

Traumax screw plate vs. Gamma nail. Blood loss in pertrochanteric fractures treated by minimally invasive osteosynthesis

Purpose This study is aimed to determine whether the Traumax dynamic hip screw reduces perioperative blood loss and transfusion rate compared to the Gamma nail in the treatment of pertrochanteric fractures. Materials and Methods A series of 331 patients were followed prospectively in a cohort study between February 2008 and October 2011 after a pertrochanteric fracture. Two types of fixation were used, 163 patients were treated with a Gamma nail and 168 patients with a minimally invasive screw plate Traumax. Perioperative blood loss, evaluated by the Mercuriali formula based on pre- and postoperative haemoglobin and transfusion rates were compared in order to assess risk factors. Results Increased perioperative blood loss was significantly linked with patient-related parameters (age, anticoagulant and platelet aggregation inhibitor treatment). Type of osteosynthesis and type of fracture were also risk factors for blood loss and transfusion. The Traumax group had significantly lower blood loss (347 ml vs. 577 ml) and transfusion rate (33.9% vs. 63.8%) than the Gamma group. Involvement of the greater trochanter increased the risk of blood loss only in the Gamma group. Functional results and bone healing were comparable at six months follow-up. Conclusion Screw plate Traumax significantly reduces perioperative bleeding after pertrochanteric fractures. It avoids fracture gaps that tend to maintain bleeding. Given the morbidity and complications related to acute anaemia and blood transfusion, the surgical management of these elderly patients is aided by this choice of fixation.

Radiological validation of a fluoroscopic guided technique for femoral implant positioning during hip resurfacing

PurposeThe positioning of the femoral cup in hip resurfacing is essential for the survival of the implant. We described a technique in 2005 to position the femoral cup guided by fluoroscopy independent of the approach performed. The main objectives were to study the positioning of the femoral components of the implant and the accuracy of the technique.MethodsBetween 2003 and 2011 we conducted a prospective study of 160 consecutive hip resurfacings all operated with this fluoroscopic-guided technique. Three independent observers performed a radiographic analysis at the pre-operative planning stage and on postoperative radiographs using OsiriX software. The statistical analysis was based on comparison of two groups by Student’s t test.ResultsThe entire implant was positioned in valgus, with an average of 7.816° valgus (p <0.001). All implants were positioned in neutral or anteverted with a mean of 1.98° (p <0.001). The risk of malpositioning on the antero-posterior plane was less than 1.41° with p <0.019. The risk of profile positioning error was lower than 0.80° with p <0.047.ConclusionThis study validates a technique of femoral implant positioning for resurfacing. It is simple, precise and independent of the approach performed.

Can the gracilis be used to replace the anterior cruciate ligament in the knee? A cadaver study

PURPOSE The purpose of this study was to evaluate whether a four-strand gracilis-only graft can be used in anterior cruciate ligament (ACL) reconstruction. STUDY DESIGN Cadaver study. METHODS This study involved 16 cadaver knees. The length and diameter of the native ACL were measured in each one. The same measurements were performed on a four-strand graft of the gracilis only, the semitendinosus only and both tendons. Students t-test was used to compare the various conditions. RESULTS The average diameter of the G4 construct was 0.07 mm greater (1%) than the native ACL (p=0.044). The average cross-sectional area of the G4 construct was 1.2 mm(2) greater (3.9%) than the native ACL (p=0.049). The G4 was on average 38.9 mm longer than the intra-articular portion of the ACL (p<0.001). CONCLUSION A four-strand gracilis construct meets the anatomical specifications for use as an ACL reconstruction graft. By using the gracilis only, the morbidity associated with harvesting the gracilis and semitendinosus tendons should be reduced. Further studies must be performed to compare the biomechanical properties of this graft with other graft types and also to evaluate how this four-strand gracilis graft behaves in a clinical setting.

BMI-related microstructural changes in the tibial subchondral trabecular bone of patients with knee osteoarthritis.

Overweight is a risk factor for osteoarthritis on the knees. Subchondral trabecular bone (SCTB) densification has been shown to be associated with cartilage degeneration. This study analyzed the microarchitectural changes in the SCTB of tibial plateaus to validate the hypothesis that the degree of remodeling is correlated with a patients body weight. Twenty‐one tibial plateaus were collected during total knee arthroplasty from 21 patients (15 women and 6 men). These patients had a mean age of 70.4 years (49–81), mean weight of 74.7 kg (57–93) and mean body mass index (BMI) of 28.4 kg/m2 (21.3–40.8). One cylindrical plug was harvested in the center of each tibial plateau (medial and lateral). Micro‐CT parameters (7.4 μm resolution) were determined to describe the SCTB structure. On the medial plateau, there were significant correlations between BMI and bone volume fraction BV/TV (r = 0.595, p = 0.004), structure model index SMI (r = −0.704 p = 0.0002), trabecular space Tb.Sp (r = 0.600, p = 0.04) and trabecular number Tb.N (r = 0.549, p = 0.01). SCTB densification during osteoarthritis is associated with a reduction in its elastic modulus, which could increase cartilage stress, and accelerate cartilage loss. SCTB densification has been shown to precede cartilage degeneration. The correlation of SCTB microarchitecture and body weight may explain why knee osteoarthritis is more common in overweight or obese patients.

Prospective Study Comparing Functional Outcomes and Revision Rates Between Hip Resurfacing and Total Hip Arthroplasty: Preliminary Results for 2 Years

There is a need of independent prospective studies about modern generation of hip resurfacing implants. The aim of this propective observational study was to compare the functional outcomes and revision rates with hip resurfacing arthroplasty and total hip arthroplasty and to present the preliminary results at 2 years. Patients included were recruited prospectively in the Partial Pelvic Replacement Hip Project by a single surgeon between January 2007 and January 2010. Patients were assessed with the Harris Hip Score (HHS) and Postel-Merle d’Aubigné (MDA) score and Devane Score. The end point of the study was reoperation for any cause related to the prosthesis. At a mean follow up of 38.6 months there were a total of 142 patients with hip resurfacing (group 1) [100 Durom® (Zimmer Inc., Warsaw, IN, USA) and 42 Birmingham Hip Resurfacing® (Smith & Nephew, Memphis, TN, USA)] and 278 patients with total hip arthroplasty (group 2). The results showed significantly greater gain of HHS, MDA and Devane score with hip resurfacing procedures. However, considering all the complications, the rate was significantly higher in group 16.4% vs 1.79% in group 2 (P<0.0001). In group 1 we observed 6 complications only concerned males with Durom® implants. The follow up of this cohort is still on going and may deliver more information on the evolution of these results in time.

Monteggia equivalent fracture associated with Salter I fracture of the radial head.

Monteggia fracture is an infrequent lesion, which associates ulna fracture and radial head dislocation. Equivalent Monteggia can occur by associated lesions such as olecranon fracture or radial neck or head fracture. We report an unusual case of Monteggia equivalent lesion associating a fracture of the proximal third of the ulnar shaft and a growth plate fracture Salter I of proximal–radial physis and divergent displacement due to a bottle-opener effect of the radial head over the capitellum during trauma. Surgical care consisted of intramedullary pinning of the radial head and fixation by a plate for ulna with a very good outcome.

Is Treatment of Segond Fracture Necessary With Combined Anterior Cruciate Ligament Reconstruction? Letter to the Editor

Dear Editor: We read with great interest the article titled ‘‘Is Treatment of Segond Fracture Necessary With Combined Anterior Cruciate Ligament Reconstruction?’’ by Melugin et al. The article focuses on the management of Segond fractures in patients undergoing anterior cruciate ligament (ACL) reconstruction. The primary challenge resides in detecting the said lesion. Segond fractures are typically identified on standard knee radiographs. However, using only radiographs underestimates the number of patients with a bony injury of the anterolateral aspect of the knee. A Segond fracture can be more reliably detected with other imaging modalities. Plain radiographs have a lower spatial resolution than magnetic resonance imaging (MRI) and especially ultrasonography (US). This means that US is more likely to detect small bone lesions. Various studies on this topic have shown that US detects a larger number of Segond fractures than MRI, with MRI being better than plain radiographs. Klos et al reported a much higher rate of detection (30%) when using US. Cavaignac et al found a large difference in the detection rate of Segond lesions based on plain radiographs (3.3%), MRI (13%), and US (50%). Ultrasonography makes it possible to detect a certain number of Segond fractures that are not fractures by definition but actually are unicortical lesions over the tibial insertion of the anterolateral ligament (ALL). A hematoma often will be present at the ALL-bone junction. This is not a fracture by definition but a bone lesion. We prefer to use the term Segond lesion instead of Segond fracture. The latter term should be used only when a fracture is visible on radiographs, whereas a Segond lesion can be detected with other imaging modalities. This left us wondering whether the control group in the Melugin et al study had Segond lesions not seen on plain radiographs, which would result in an analysis bias that no longer makes the groups comparable. Some patients in the control group may have belonged in the Segond fracture group. While it can be said that a Segond lesion corresponds to an ALL lesion, not every ALL lesion is a Segond lesion. The indirect question asked by Melugin et al directly leads to the treatment of two injuries: ACL and anterolateral structures. The problem is that the control group in Melugin’s study likely contained patients with an ALL injury that was missed because it was not revealed by the presence of a radiographically detectable Segond fracture. We believe this is a major confounding factor in the study. Each patient underwent an MRI examination. The anterolateral region of the knee could have been analyzed with MRI instead of solely with radiographs. The plausibility of a result is an important element for validating the method of a study. Melugin et al compared their clinical outcomes to the findings published by Sonnery-Cottet et al after ACL and ALL reconstruction. Melugin et al believed that their clinical outcomes were comparable to published results. We believe it would be relevant for the investigators to disclose the prevalence of Segond lesions found on plain radiographs and MRI, especially since the patients had already undergone MRI. If the prevalence of Segond fractures is very low, then an analysis bias may be present due to the inability to diagnose Segond fractures. Melugin et al reported their analysis of the healing of Segond fractures. Can effective healing be seen on plain radiographs? We believe that plain radiographs are not sufficient to draw conclusions about fracture healing. Due to bone superimposition, bone fragments may appear to be continuous with the anterolateral portion of the tibia even when the bones have not yet healed. Only 3D imaging (computed tomography scan or MRI) or imaging focused on this area (US) can determine whether this type of injury has healed. The lack of difference found between the study and control groups can be due to several factors: (1) there is actually no difference, (2) the tools used to measure the difference were not powerful enough to detect it, (3) the groups being compared differed only in the studied variable, (4) the minimal clinically important difference (MCID) used was not determined from a comparable population. We believe the last three factors can explain the findings of Melugin et al. We identified several sources of bias: analysis bias (underestimation of the number of Segond lesions), selection bias (potential Segond lesions in the control group), and interpretation bias (20% lost to follow-up; distribution of bone–patellar tendon–bone vs hamstring graft not comparable between groups). To answer the investigators’ question—Is Treatment of Segond Fracture Necessary With Combined Anterior Cruciate Ligament Reconstruction?—a more appropriate study design would entail a population of ACL-injured patients with Segond fracture that compares a group undergoing only ACL reconstruction to a group undergoing a combined ACL-anterolateral procedure. Furthermore, the MCID reported, 11.5, was based on a study of patients with a mean age of 40.5 years (range, 12.5-81.3 years), and the most frequent diagnosis in that group was osteoarthritis. To our knowledge, no studies have determined the MCID of the International Knee Documentation Committee (IKDC) score in young patients with ACL injury. However, other authors have reported that the alternative The American Journal of Sports Medicine 2018;46(5):NP13–NP16 2018 The Author(s)