Etienne Cavaignac

Ultrasonographic Identification of the Anterolateral Ligament of the Knee

PURPOSEnTo determine ultrasonographys sensitivity for identifying the anterolateral ligament (ALL).nnnMETHODSnA descriptive study of 18 cadaveric knees was performed. Ultrasonography was used to locate any anterolateral structures at the knee that could correspond to the ALL. The structures length and relation with other notable anatomic landmarks (fibular head, Gerdy tubercle, joint line, lateral femoral epicondyle, popliteus tendon insertion) were quantified. The ultrasonography measurements were validated by dissecting each knee. The sensitivity of ultrasonography for detecting the ALL and the agreement between the ultrasonographic and cadaveric measurements (Cohen κ) were determined by statistical analysis.nnnRESULTSnThe ALL was found in all 18 cadaveric knees and corresponded anatomically to the ultrasonographic descriptions. Ultrasonography had 100% sensitivity for detecting thexa0presence of the ALL. The ALLs insertion on the lateral femoral condyle was, on average, 12.08 mm (SD, 4 mm; range, 7 to 15 mm) proximal and posterior to the lateral femoral epicondyle and 20.5 mm (SD, 3 mm; range, 16 to 24 mm) proximal to the middle of the popliteus tendon insertion. The ALL inserted onto the tibia, midway between the Gerdy tubercle and the fibular head; the distance between the midpoint of the tibial insertion and middle of the Gerdy tubercle was 19.05 mm (SD, 2.1 mm; range, 15 to 25 mm), and the distance was 19.13 mm (SD, 2.3 mm; range, 14 to 23 mm) to the tip of the fibular head. The agreement between the ultrasonographic and cadaveric findings was excellent (Cohen κ coefficient between 0.88 and 0.94).nnnCONCLUSIONSnUltrasound imaging is a suitable tool for identifying the ALL of the knee, and it allowed for a detailed analysis of the entire ALL in all 18 knees. However, its ability to evaluate any injuries to the ALL must still be shown.nnnCLINICAL RELEVANCEnUltrasonography can be used to confirm the integrity of the ALL.

Anterior Cruciate Ligament Reconstruction in Children With A Quadrupled Semitendinosus Graft: Preliminary Results With Minimum 2 Years of Follow-up

Background: The management of anterior cruciate ligament (ACL) tears in growing patients must balance activity modification with the risk of secondary (meniscal and cartilaginous) lesions, and surgical intervention, which could adversely affect skeletal growth. Many ACL reconstruction techniques have been developed or modified to decrease the risk of growth disturbance. We have not found any description of ACL reconstruction using a single hamstring, short graft implanted into intraepiphyseal, retroreamed sockets. Our hypothesis was that the technique that we used restored the knee stability and did not cause any growth disturbances. Methods: We retrospectively studied 28 patients (20 boys, 8 girls) who presented with a unilateral ACL tear and open growth plates. We performed short graft ligament reconstruction with the semitendinosus folded into 4 strands around 2 polyethylene terephthalate tapes. The graft was implanted into sockets that were retroreamed in the femoral and tibial epiphysis and the tapes were fixed remotely by interference screws. After a minimum period of 2 years, we evaluated the comparative knee laxity, the radiographic limb morphology, the appearance of secondary lesions, and the functional outcomes using the Lysholm and Tegner scores. Comparative analyses were performed using the Student t test with subgroups depending on the type of fixation used. Results: The mean age of the patients was 13 years (range, 9 to 15 y). The mean follow-up was 2.8 years (range, 2 to 5 y). The mean difference in laxity at 134 N was 0.3 mm, as determined using a GNRB arthrometer. No patients reported meniscal symptoms or degenerative changes. We found no angular deformity or leg length inequality. Two patients suffered a recurrent ACL tear. Conclusions: The preliminary results from this series are consistent with prior studies demonstrating that intraepiphyseal ACL reconstruction is a safe reliable alternative for the pediatric population. Study Design: Case series; level of evidence 4.

Evaluation of the accuracy of patient-specific cutting blocks for total knee arthroplasty: a meta-analysis

PurposeBecause published studies on the accuracy achieved with patient-specific guides during total knee arthroplasty (TKA) contradict each other, this systematic review and meta-analysis sought to compare radiological TKA outcomes when patient-specific cutting blocks (PSCB) were used to the outcomes when standard manual instrumentation was used.MethodsThe meta-analysis was implemented according to PRISMA Statement Criteria. The primary endpoint was the hip-knee-ankle (HKA) angle, which represents the leg’s mechanical axis. The accuracy of component placement in the coronal and sagittal planes, and the accuracy of femoral component rotation were also compiled. After testing for publication bias and heterogeneity across studies, data were aggregated random-effects modeling when necessary.ResultsFifteen articles were included: 916 total knee arthroplasty cases in the PSCB group and 998 in the MI group. The mechanical axis did not differ between the two groups (weighted mean difference 0.07°; 95xa0% CI, -0.5° to 0.65°; pu2009=u20090.8). Risk ratio analysis revealed no protective effect of using PSCB relative to the appearance of HKA angle outliers (RRu2009=u20090.88; 95xa0% CI, 0.68–1.13; pu2009=u20090.3). There was a trend towards a protective effect with PSCB for the risk of femoral component outliers, but the opposite was observed for the tibial component. The implantation procedure was stopped in 30 cases because the surgeon-authors found excessive discrepancies between the intra-operative observations and the pre-operative plan.ConclusionsThis meta-analysis found no evidence that using patient-specific cutting blocks provides superior accuracy to using manual instrumentation during TKA.

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 (Pu2009=u20090.00007), 3.44° with the 45° Dunn view (Pu2009=u20090.004) and 13.47° with the cross-table view (Pu2009=u20090.002).ConclusionsThis experimental study confirmed the value of the frog-leg 45/45/30 view in assisting diagnosis of cam-type FAI.

Hip resurfacing: a systematic review of literature

PurposeWe conducted a systematic review of the literature in order to take stock of hip resurfacing according to the principle of “evidence based medicine”. Our main objective was to compare the rate of revision of resurfacing implants with survival limits set by the National Institute of Clinical Excellence (NICE).MethodsA systematic review was undertaken of all published (Medline, Cochrane, EMBASE) literature research databases up to July 2012 as recommended by the PRISMA statement. Data extraction focused on functional outcomes, complications and survival rates. The survival rates of implants were analysed according to the mean of the series in comparison to the NICE criteria.ResultsFifty-three studies were identified and included 26,456 cases with an average of 499.17 ± 856.7 (range, 38–5000) cases per study. The median survival was 95.57xa0% ± 3.7 % (range, 84–100). The percentage of studies which satisfied the criteria set by NICE was 69.8xa0%. In terms of cumulative revision rates pondered by the number of implants, BHR®, Conserve Plus® and Cormet® showed the best results. The mean postoperative score was 91.2 ± 7.72 (range, 68.3–98.6). There was no statistically significant difference between implants in terms of functional outcomes.ConclusionOn the basis of the current evidence base, this review of the literature emphasises the importance of certain parameters that can improve the results of resurfacing. The type of implant seems to play an important role as does patient selection.

Ultrasonographic Evaluation of Anterolateral Ligament Injuries: Correlation With Magnetic Resonance Imaging and Pivot-Shift Testing

PURPOSEn(1) To compare the diagnostic ability of ultrasonography (US) and magnetic resonance imaging (MRI) to detect anterolateral ligament (ALL) injuries in anterior cruciate ligament (ACL)-deficient patients, and (2) to evaluate the correlation between ALL injury status (as determined by US and MRI) and the knees rotational stability.nnnMETHODSnThirty patients with an isolated ACL injury were included prospectively over a 3-month period. The condition of the ALL was evaluated by 2 experienced radiologists using both US and MRI. Rotational stability was evaluated by 2 surgeons with the pivot-shift test with patients under general anesthesia. It was classified as either negative (grades 0 and I) or positive (grades II and III). The radiologists were blinded to the knees rotational stability, and the surgeons were blinded to the ALLs status based on the US images. The correlation between the ALLs injury status (US and MRI) and the pivot shift was determined with the Pearson χ2 test. To evaluate the reproducibility of the results, the agreement between observers was determined with the Cohen κ coefficient.nnnRESULTSnOn US, the ALL was identified and visible over its entire length in 100% of patients (30 of 30, κxa0= 1). The ALL was injured in 63% of patients (19 of 30, κxa0= 0.93). On MRI, the ALL was identified in 96% of patients (29 of 30, κxa0= 0.91). The ALL appeared injured in 53% of cases (16 of 30, κxa0= 0.93). An ALL that appeared injured on US was more often associated with a positive pivot shift than was an uninjured ALL (75% vs 39%, χ2xa0= 13.7, P < .05). The interobserver agreement was high for both US (κxa0= 0.91-1) and MRI (κxa0= 0.76-1).nnnCONCLUSIONSnUS is a reproducible examination for the diagnosis of ALL injury. An ALL injury is most often associated with a high pivot-shift grade.nnnLEVEL OF EVIDENCEnLevel II, prospective comparative study.

Is Quadriceps Tendon Autograft a Better Choice Than Hamstring Autograft for Anterior Cruciate Ligament Reconstruction? A Comparative Study With a Mean Follow-up of 3.6 Years.

Background: The quadriceps tendon (QT) autograft is known as an effective graft for anterior cruciate ligament (ACL) reconstruction and shows a similar functional outcome to the bone-patellar tendon-bone (BPTB) in randomized controlled trials, with a lesser incidence of complications. Up until now, only 2 studies have compared QT to hamstring tendon (HT) autograft. Hypothesis: The functional outcomes of the QT technique are at least as good as those of the HT technique, with the same morbidity. Study Design: Cohort study; Level of evidence, 3. Methods: Ninety-five patients underwent isolated ACL reconstruction between January 1 and December 31, 2012. Fifty underwent ACL reconstruction with the QT and 45 with the HT. The same surgical technique, fixation method, and postoperative protocol were used in both groups. The following parameters were evaluated: surgical revisions, functional outcome (Lysholm, Knee injury and Osteoarthritis Outcome Score [KOOS], Tegner, subjective International Knee Documentation Committee), joint stability (KT-1000, Lachman, pivot shift), anterior knee pain (Shelbourne-Trumper score), and isokinetic strength. Descriptive statistics are presented for these variables using the Student t test. Results: Eighty-six patients (45 QT, 41 HT) were reviewed with a mean follow-up of 3.6 ± 0.4 years; minimum follow-up was 3 years. There were 4 reoperations in the QT group (including 1 ACL revision) and 3 in the HT group (including 2 ACL revisions) (P > .05). The Lysholm (89 ± 6.9 vs 83.1 ± 5.3), KOOS Symptoms (90 ± 11.2 vs 81 ± 10.3), and KOOS Sport (82 ± 11.3 vs 67 ± 12.4) scores were significantly better in the QT group than in the HT group. In terms of stability, the mean side-to-side difference was 1.1 ± 0.9 mm for the QT group and 3.1 ± 1.3 mm for the HT group based on KT-1000 measurements (P < .005). The negative Lachman component was higher in the QT group than in the HT group (90% vs 46%, P < .005). There was a trend for the negative pivot-shift component to be higher in the QT group than in the HT group (90% vs 64%, P = .052). The Shelbourne-Trumper score was the same in both groups. There was no difference between groups in terms of isokinetic strength. Conclusion: The use of a QT graft in ACL reconstruction leads to equal or better functional outcomes than does the use of an HT graft, without affecting morbidity.

Cadaveric study comparing the biomechanical properties of grafts used for knee anterolateral ligament reconstruction

PURPOSEnTo measure the biomechanical properties (maximum load, stiffness, and elongation) of the anterolateral ligament (ALL), gracilis, and iliotibial band (ITB) within the same subject.nnnMETHODSnThirteen unpaired knees were used (7 women, 6 men). The donors had a mean age at death of 54xa0years (range: 37 to 70xa0years). The mechanical properties of two types of ALL grafts were evaluated: ITB and two-strand gracilis. The mechanical properties of ALL were also measured. Validated methods were used to perform the tensile tests to failure and to record the results. Students t-test was used to compare the various samples.nnnRESULTSnThe maximum load to failure was 141xa0N (±40.6) for the ALL, 200.7xa0N (±48.7) for the gracilis, and 161.1xa0N (±27.1) for the ITB. Only the gracilis had a significantly higher failure load than ITB and ALL (Pxa0= .001 and Pxa0= .03). The stiffness was 21xa0Nxa0mm-1 (±8.2) for the ALL, 131.7xa0Nxa0mm-1 (±43.7) for the gracilis, and 39.9xa0Nxa0mm-1 (±6) for the ITB. The elongation at failure was 6.2xa0mm (±3.2) for the ALL, 19.9xa0mm (±6.5) for the gracilis, and 20.8xa0mm (±14.7) for the ITB.nnnCONCLUSIONSnThe gracilis had the highest maximum load to failure. The ITBs mechanical properties most closely resemble those of the ALL.nnnCLINICAL RELEVANCEnThe biomechanical properties of each potential ALL graft can be factored in when deciding which type of graft to use.

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 (BMIu2009>u200930 kg/m²) (exposed group) and non-obese patients (BMIu2009≤u200930 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 58.3u2009±u200927 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 %, pu2009>u20090.05). No cases of loosening were found. Revisions were secondary to deep or superficial infection (nu2009=u200922), periprosthetic femur fracture (nu2009=u200910) or haematoma (nu2009=u20093).ConclusionThese findings imply that double-mobility cups are a reliable way of reducing the risk of dislocation in obese patients after primary THA.

Bone lengthening using the Fitbone(®) motorized intramedullary nail: The first experience in France.

INTRODUCTIONnIntramedullary limb lengthening systems include mechanical systems (the Albizzia nail and the ISKD nail) as well as motorized systems with the Fitbone(®) (Wittenstein, Igersheim, Germany) and the Precice(®) (Ellipse Technologies, Irvine, CA, USA) nails. We hypothesized that limb lengthening using the Fitbone(®) nail was reliable, reproducible, and comfortable for the patient.nnnPATIENTS AND METHODSnBetween 2010 and 2013, a prospective single-center, single-operator (FA) study was conducted on patients who had undergone limb lengthening using the Fitbone(®) nail. The inclusion criteria were length discrepancy of the limbs equal to or greater than 25xa0mm or a short stature. The exclusion criteria were indications for cosmetic reasons and/or growth plates that were still open. The lengthening parameters were assessed postoperatively and at the last follow-up. Lengthening was considered achieved when the lengthening objective did not differ by more than 5xa0mm. All complications were noted. A statistical analysis was performed.nnnRESULTSnTwenty-six Fitbone(®) nails were implanted in 23 patients, in the femur in 15 cases and the tibia in 11 cases. The patients mean age was 22.5xa0years (range: 15-53xa0years) and the mean follow-up was 3.4xa0years (range: 2-5.3xa0years). The limb lengthening targeted was obtained in 23 cases (88%) and the mean lengthening was 45.3±18xa0mm (range: 20-80xa0mm). The mean time to healing was 277±167xa0days (range: 86-638xa0days). The mean healing index was 73±57xa0days/cm for the femurs and 83.5±65xa0days/cm for the tibias. The mean complication rate was 15.4%.nnnDISCUSSIONnThis study emphasizes the good short-term results of this motorized intramedullary lengthening system. An evaluation over the longer term and with a higher number of patients remains necessary.nnnLEVEL OF EVIDENCEnIV: uncontrolled, prospective, continuous study.