Knee Surg Sports Traumatol Arthrosc (2014) 22 (Suppl 1):S1–S5 DOI 10.1007/s00167-014-2916-6
Star Paper Session AW11-1129 Extra-articular reconstruction and Pivot shift: ‘‘in vivo’’ dynamic evaluation with navigation Monaco E.*1, Maestri B.1, Mazza D.1, Iorio C.1, Ferretti A.1 1 University of Rome La Sapienza, Sant’Andrea Hospital, Rome, Italy Objectives: The pivot shift is considered the most reliable test used to evaluate the results of the ACL reconstruction as it strongly correlates with the satisfaction of the patient, giving way episodes and activity level. The purpose of this paper is to biomechanically investigate the effect of intra-articular and extra-articular reconstructions on the pivot shift phenomenon as evaluated by navigation. Methods: Twenty patients underwent anatomic single bundle ACL reconstruction with doubled semitendinosus and gracilis tendons with the addition of extra-articular reconstruction as described by CokerArnold (modification of the MacIntosh procedure). The patients were randomized into two groups. In group A, the intra-articular reconstruction was performed first and then the lateral tenodesis was fixed; in group B, the protocol was reversed. The navigation system used was the 2.2 OrthoPilot ACL (B. Braun-Aesculap, Tuttlingen, Germany). The actual version of the software allows the system not only to statically calculate manual maximum anterior tibial translation (ATT) and manual maximum internal rotation (IR) and external rotation (ER) at different degrees of knee flexion but also to dynamically evaluate ATT ad rotation during the Pivot shift test. Measurements were performed before the reconstruction, after the first procedure and after the second procedure in each patient. Results: Static evaluation: The ACL reconstruction is more effective than lateral tenodesis in significantly reducing AP translation (p = 0.03); the addition of the lateral tenodesis to the ACL reconstruction is statistically more effective than the addition of the ACL to the lateral tenodesis in reducing the rotation (p = 0.0025); the addition of the ACL reconstruction to the lateral tenodesis is statistically more effective than the addition of the lateral tenodesis to the ACL reconstruction in reducing the AP translation (p = 0.002). Dynamic evaluation (Pivot shift test): The intra-articular ACL reconstruction alone is as effective as lateral tenodesis alone in reducing post op AP translation and rotation during the Pivot shift; the addition of the lateral tenodesis to the ACL reconstruction is statistically more effective than the addition of the ACL reconstruction to the lateral tenodesis in reducing the rotation during the pivot-shift (p = 0.0146). Conclusions: The extra-articular reconstruction has no effect in reducing the anterior displacement of the tibia at 30° of flexion (Lachman test) but it is more effective than intra-articular reconstruction in reducing tibial rotation in a static condition. Anatomic ACL reconstruction and lateral tenodesis are synergic in controlling pivot shift phenomenon in a dynamic condition and seems to be biomechanically justified in a clinical setting to reduce the Pivot shift phenomenon. ACL, extra-articular reconstruction, pivot-shift, navigation.
AW11-1375 Platelet-rich plasma injections in acute hamstring muscle injuries: a randomised controlled trial Reurink G.*1, Goudswaard G.2, Moen M.3, Weir A.2, Verhaar J.1, Bierma-Zeinstra S.1, Maas M.4, Tol J.2 1 Erasmus Medical Centre, Rotterdam, Netherlands; 2Aspetar Orthpedic and Sports Medicine hospital, Doha, Qatar; 3Bergman Clinics, Naarden, Netherlands; 4Academic Medical Centre, Amsterdam, Netherlands Objectives: Platelet-rich plasma (PRP) injection, derived from autologous blood, is an innovative treatment method that is used worldwide in acute muscle injuries, which are the most prevalent time loss injuries with a high recurrence rate and an enormous financial burden in professional sports. The hamstrings are the most commonly injured muscles. The increasing interest in PRP is emphasized by the rapidly growing global PRP market, which is estimated to triple from 2009 to 2016. After the World Anti-Doping Agency allowed intramuscular applications of PRP in 2011, its use in muscle injuries has been increasing ever since. Basic science in animal models showed that PRP has regenerative effects on muscle tissue, but evidence from high quality clinical studies is lacking. We examined whether PRP injections would be efficacious in acute hamstring muscle injuries. This is the first double-blind, randomised, placebo-controlled trial on the efficacy of PRP in acute muscle injuries. Methods: In three Sports Medicine clinics we included 80 athletes with acute hamstring muscle injuries, confirmed on MRI. We randomised the patients to PRP (PRP-group) or isotonic saline injections (placebo-group). Patients received two injections: at inclusion within 5 days after injury and the second injection five to 7 days after the first. The researchers and the patients were blinded to the content of the syringe. To ensure blinding we prepared a PRP and a placebo syringe for each patient. Both groups undertook a standardized criteria-based rehabilitation program, supervised by a physiotherapist. The primary outcome measure was the time needed to return to play during 6 months follow-up, analysed with a Cox proportionalhazards model. Secondary outcome measures were: Re-injuries within 2 months after return to play, perceived recovery, patient satisfaction, hamstring force, hamstring flexibility and hamstring function measured with the Hamstring Outcome Score. Results: Mean age of the patients was 29 ± 7 years and the majority played soccer (71 %) or field hockey (15 %) on a competitive level (74 %). There were no patients lost to follow-up for the primary outcome analysis. The median time to return to play was 42 days (interquartile range, 30–58) in the PRP-group, as compared to 42 days (interquartile range, 37–56) in the placebo-group (hazard ratio, 0.96; 95 % CI 0.61–1.51: p = 0.66). The re-injury rate was 16 % in the PRP-group and 14 % in the placebo-group (Odds ratio 1.17; 95 % CI 0.33–4.18: p = 0.814). There were also no significant differences on the other secondary outcome measures. Conclusions: We found no benefit of intramuscular PRP injections compared to isotonic saline injections in patients with acute hamstring injuries. Platelet-rich plasma, muscle injury, injection, hamstring.
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S2 AW11-1427 A novel synthetic meniscus implant for the treatment of middle aged patients: Results of 118 patients in a prospective, multicenter study Condello V.*1, Arbel R.2, Agar G.3, Rozen N.4, Angele P.5, Victor J.6, Brittberg M.7, Verdonk P.8 1 Sacro Cuore Don Calabria Hospital, Sports Medicine and Arthroscopic Surgery, Negrar (Verona), Italy; 2Tel Aviv Souraski Medical Center, Sports Medicine and Arthroscopic Surgery, Tel Aviv, Israel; 3Asafh Harofe Medical Center, Beer Jacob, Israel; 4 Emek Medical Center, Afula, Israel; 5Klinikum der Universita¨t Regensburg, Unfallchirurgie, Regensburg, Germany; 6Ghent University Hospital, Orthopaedic Surgery and Traumatology, Gent, Belgium; 7Gothenburg University, Gothenburg, Sweden; 8Antwerp Orthopedic Center, Monica Hospitals, Antwerp, Belgium Objectives: This study aims to evaluate short-term clinical and MRI outcomes of a non-anchored polycarbonate-urethane meniscus implant for medial knee pain in middle-aged patients (Fig. 1). In the younger population, surgical options e.g., allografts and artificial scaffolds are available and have been shown to be effective. For middle-aged patients, the clinical benefit from surgical intervention of a degenerated meniscus has only been reported in a fraction of cases. These patients are too young for more aggressive treatments such as UKA or TKA. This paper presents the first clinical results of a multicenter study, after a minimum of 1 year follow-up. Methods: 118 patients (age 30–73) were treated. All of the patients reported medial knee pain which was associated with either a severely degenerated and non-functional meniscus (18 %) or post-meniscectomy knee pain with grade II-III degenerative changes (Outerbridge) of the medial cartilage (82 %). Patients with grade IV medial cartilage loss or instability were excluded. Primary clinical outcome was measured by the KOOS scale up to 24 months, with secondary outcomes measured by IKDC subjective and VAS questionnaires for pain. Serial MRI scans were taken at 6 weeks, 12- and 24-month follow-up to evaluate the condition of the articular cartilage.
Fig. 1 The medial meniscus implant as located between the medial condyle and the tibia plateau in a curb created by the remaining meniscal rim
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Fig. 2 The results of subjective pain questionnaires a KOOS, and b VAS, as reported by patients implanted with the meniscus implant over 2 years (n = 118 at the baseline, n = 104 at 6 weeks, n = 91 at 6 months, n = 61 at 1 year, and n = 13 at 2 years)
Results: Patients showed a considerable clinical improvement after implantation. Specifically, KOOS Pain and Pain VAS scores were improved by *60 % (p \ 0.05), after 6, 12 and 24 months follow up (Fig. 2), and patient activity levels also were found to increase following implantation. The first MRI findings can be considered promising, with no signs of cartilage deterioration in the majority of the patients. Main complications so far include 11 cases (9.3 %) of either a dislocation and/or fracture of the device. These were mainly due to implantation of a too small implant and/or patients with high BMI or high level of post-op activity. In five cases (4.2 %), not removing enough of the posterior or anterior horns causes subluxation. Three cases of operation- room infection, two cases of re-sizing, four cases of stiff joint and three cases of transient squeak knee were observed. Conclusions: This study was designed to evaluate and obtain assurance of the safety and efficacy ratio of a novel medial meniscus implant in the treatment of a challenging patient cohort. Short-term outcomes are promising and long-term results are ongoing. Knee, polycarbonate-urethane, prosthesis, join replacement. NUsurface Study Group (Alphabetical order): Agar G, MD, Israel Arbel R, MD, Israel Beer Y, MD, Israel Ben-Haim T, MD, Israel Blumberg N, MD, Israel Condello V, MD, Italy Hershman E, MD, USA Prof. Rozen N, MD, PhD, Israel Van Der Straeten, MD, PhD, Belgium Prof. Verdonk P, MD, PhD, Belgium Prof. Verdonk R, MD, PhD, Belgium
Knee Surg Sports Traumatol Arthrosc (2014) 22 (Suppl 1):S1–S5 Prof. Victor J, MD, PhD, Belgium Israeli S, MD, Israel Prof. Angele P, MD, PhD, Germany Zellner J, MD, Germany A Weiler, MD, Berlin, Germany Prof. Brittberg M, MD, PhD, Sweden Shabshin N, MD, Israel Prof. Zorzi C, MD, Italy AW11-1635 Long-term degradation of poly-lactide co-glycolide/betatricalcium phosphate biocomposite anchors in arthroscopic Bankart repair. A prospective study Compagnoni R.*1, Ragone V.1, Aliprandi A.1, Carminati S.1, Bruno V.1, Randelli P.1 1 Policlinico San Donato, San Donato Milanese, Italy Objectives: To evaluate, using MR, the biological efficacy of anchors made of 30 % tricalcium phosphate and 70 % poly-lactic-co-glycolide (PLGA) used for the repair of Bankart lesion following shoulder instability. Methods: Twenty consecutive patients who were candidates for surgical treatment of unidirectional, post- traumatic shoulder instability were treated arthroscopically with anchors made of 70 % PLGA + 30 % beta- tricalcium phosphate preloaded with OrthoCord sutures. Fifteen of them were evaluated by MR at least 16 months after the intervention. A second evaluation was performed at least 12 months after the first in the patients (N = 5) in whom implanted anchors were still visible at the first evaluation with a low intensity signal in all sequences. Two radiologists, with different experience (15 and 3 years), separately evaluated the MR patterns of the trabecular glenoid bone, the walls of the bone tunnel and the signal from the anchors. The following parameters were considered in the MR evaluation: integrity of the tunnel edge (grade 0–2), the intensity of the signal from the anchor site (grade 1–3) and cystic lesions. The normal signal from the glenoid trabecular bone has been used as the reference parameter. The anchors were considered independent variables and so each one was analysed individually, even in the same patient. At the final clinical follow-up, a ROWE questionnaire was filled in for each patient. Results: Overall, 44 anchors were evaluated (33 anchors in the first +11 anchors in the second follow-up). The mean follow-up was 28.6 months. Except for two patients (10 %) none of the other patients had any episodes of dislocation. No cystic lesions were detected by MR imaging. The interobserver concordance between the two radiologists calculated with Khoen’s k was substantial (k = 0,780 and k = 0,791 for integrity of the tunnel edge and for intensity of the signal from the anchor site respectively). Both the integrity of the tunnel border and the intensity of the signal in the site of anchors that had been implanted more than 24 months prior to the evaluation were significantly different from those of anchors implanted less than 24 months (tunnel border grade, 0: 41 %, 1: 50 %, 2: 9 % vs 0: 4.5 %; 1: 50 %; 2: 45.5 %, p = 0.003; anchor signal grade, 1: 41 %, 2: 45.5 %, 3: 13.5 % vs 1: 13.5 %; 2: 41 %; 3: 45.5 %, p = 0.03). Analysis of the linear contrasts (ANOVA) showed a linear increase in the mean values of the times to increased tunnel border grade (grade 0: 22 ± 4 months; grade 1: 27 ± 8 months; grade 2: 29 ± 5 months; p = 0.02) and grade of intensity of the signal in the anchor site (grade 1: 24 ± 6 months; grade 2: 26 ± 7 months; grade 3: 29 ± 7 months; p = 0.05). Conclusions: Anchors made of 30 % b-tricalcium phosphate and 70 % PLGA did, therefore, show excellent biological efficacy, without causing significant cystic lesion, producing gradual changes in the MR signal that seems to became equivalent to that of the glenoid trabecular bone in a mean time of 29 months after implantation. Shoulder instability.
S3 AW11-1964 Comparison of Glenohumeral Contact Pressures and Contact Areas After Posterior Glenoid Reconstruction With Iliac Crest or Distal Tibia Osteochondral Allograft Frank R.*1, Shin J.2, Saccomanno M.3, Provencher M.4, Romeo A.1, Verma N.1 1 Rush University Medical Center, Department of Orthopaedic Surgery, Chicago, United States; 2University of Saskatchewan, Royal University Hospital, Saskatoon, Canada; 3Catholic University, Department of Orthopaedic Surgery, Rome, Italy; 4Harvard University, Massachusetts General Hospital, Boston, United States Objectives: While offering the same benefit of posterior shoulder stabilization, posterior glenoid reconstruction with distal tibia allograft offers the theoretical advantage of improved joint congruity and a cartilaginous articulation with the humeral head over iliac crest reconstruction. To evaluate glenohumeral contact areas, contact pressures, and peak forces in (1) the intact glenoid and after (2) 20 % posterior glenoid surface area defect from 6 o’clock to 10 o’clock (right shoulder), (3) 20 % glenoid defect with flush posterior bone block graft with ICBG; and (4) 20 % glenoid defect with DTA. The hypothesis was that reconstruction with DTA would more effectively restore normal glenoid contact pressures (CP), contact areas (CA), and peak forces (PF) when compared to the deficient glenoid. Methods: Eight fresh-frozen human cadaveric shoulders were randomly tested in four conditions as follows: (1) intact glenoid, (2) 20 % posterior-inferior glenoid surface area defect, (3) 20 % defect reconstructed with flush ICBG; and (4) 20 % defect reconstructed with fresh DTA. A Materials Testing System was used to apply a compressive load of 440-N for each condition in the following clinically relevant arm positions: (1) neutral (scapular plane), (2) 60° humeral abduction, and (3) 90° flexion-45° internal rotation (FIR). Results: Glenoid reconstruction with DTA resulted in significantly higher CA compared to the 20 % defect model in neutral (4.40 ± 0.97 vs 3.66 ± 0.50 cm2, respectively) and 60° (4.80 ± 0.73 vs 3.80 ± 0.50 cm2, respectively). There were no differences in the CA between ICBG and the 20 % defect state in either the neutral or 60° positions. The intact state exhibited significantly higher CA than the defect (p \ 0.01) and ICBG (p \ 0.05) in all positions. Reconstruction with both DTA and ICBG resulted in significantly lower CP compared to the defect state at 60° of abduction (4.14 ± 0.97 vs 4.19 ± 0.95 vs 4.51 ± 1.11 kg/cm2, respectively). Reconstruction with DTA resulted in lower PF compared to ICBG in all positions (neutral, 60°, and FIR). Conclusions: Reconstruction of posterior glenoid bone defects with DTA may allow for improved joint congruity with higher CA and lower PF within the glenohumeral joint than ICBG reconstruction. While these mechanical properties may translate into clinical differences, further studies are needed to understand their effects. Shoulder instability, posterior glenoid, glenoid bone defect, distal tibia allograft.
AW11-2426 Metal resurfacing inlay implant for osteochondral defects of the talus after failed previous surgery: a prospective study van Bergen C.*1, van Eekeren I.2, Reilingh M.1, Gerards R.1, Sierevelt I.3, van Dijk C.4 1 Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands; 2Academic Medical Center Amsterdam, Orthopedic Surgery, Amsterdam, Netherlands; 3Slotervaart Hospital, Dept. of Orthopaedic Surgery, Amsterdam, Netherlands; 4Academisch Medisch Centrum, University of Amsterdam, Amsterdam, Netherlands Objectives: Osteochondral ankle defects (OCDs) mainly occur in a young, active population. In 63 % of cases the defect is located on the medial talar dome. Arthroscopic debridement and microfracture is
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S4 considered the primary treatment for defects up to 15 mm. To treat patients with a secondary OCD of the medial talar dome and avoid donor site morbidity, a 15-mm diameter metal resurfacing inlay implant was developed. The present study aimed to evaluate the clinical effectiveness of the metal implant for OCDs of the medial talar dome. Methods: We prospectively studied 22 consecutive patients for a mean of 3 years and 4 months (range, 2–5 years). We included patients with an OCD of the medial talar dome, with the largest diameter being between 12 mm and 20 mm as measured on CT scans. For inclusion patients had to have complained persistently for more than a year after previous surgical treatment. Exclusion criteria included an age \ 18 years, ankle osteoarthritis grade III, other ankle pathology, and diabetes mellitus. The primary outcome measure was the Numeric Rating Scale of pain (NRS) at rest and during walking, running, and stair climbing. Secondary outcome measures were the Foot Ankle Outcome Score (FAOS), American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Short-Form 36 (SF-36) and radiographic evaluation. Results: There was statistically significant reduction of the NRS pain in each of four situations (p \ 0.01; repeated measures ANOVA). For example, the NRS during walking improved from a mean of 6.7 ± 1.2 preoperatively to 3.4 ± 2.9 at final follow-up. The FAOS improved on all subscales (p \ 0.03; repeated measures ANOVA). The AOFAS score improved from a median of 62 (range, 28–75) preoperatively to 82 (range, 46–100) at final follow-up (p \ 0.01; Friedman’s two-way analysis of variance by ranks). The SF-36 physical component scale improved from a mean of 36 ± 8 pre-operatively to 48 ± 15 at final follow-up (p \ 0.01; repeated measures ANOVA); the mental component scale did not change significantly. On radiographs, degenerative changes were observed in four patients. One patient required additional surgery for the OCD. Conclusions: This study shows that a metal implant is a promising treatment for OCDs of the medial talar dome after failed previous surgery.
AW11-2436 The Tibial Tubercle—Posterior Cruciate Ligament Distance: An independent review of this new measurement Anley C.*1, Saithna A.1, Morris G.1, James S.1, Snow M.1 1 Royal Orthopaedic Hospital, Birmingham, United Kingdom Objectives: The Tibial Tubercle-Trochlear Grove (TT-TG) distance is commonly used to assess patellar mal- alignment, however measuring the TT-TG in patients with trochlear dysplasia can be inaccurate due to the absence of landmarks. To obviate these factors, Seitlinger et al. [1] have recently suggested a new measurement to assess the position of the tibial tubercle in patients with anterior knee pain, namely the Tibial Tubercle- Posterior Cruciate Ligament Distance (TT-PCL). The TT-PCL distance is the mediolateral distance between the midpoint of the insertion of the patellar tendon and the medial border of the posterior cruciate ligament parallel to the dorsal tibia condylar line [1]. In their study they concluded this was a reliable measurement and that the normal TT-PCL was \24 mm. The aim of our study was to independently assess the interobserver and intraobserver reliability of this measurement and in addition to asses the incidence of true lateralization of the tibial tubercle in our study population. Methods: The magnetic resonance imaging (MRI) scans of 100 knees, with patellar pathology, were identified. The TT-PCL was measured according to the method originally described by Seitlinger et al. Measurements where preformed independently by two fellowship trained orthopaedic surgeons. Twenty measurements where repeated on a separate occasion to allow for an assessment of the intra-rater reliability. Inter-observer and intra- observer reliability was evaluated via the intra-class correlation coefficient. The results of the TT-PCL distance were examined in patients with an abnormal TT-TG based on two values, [20 mm (accepted
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Knee Surg Sports Traumatol Arthrosc (2014) 22 (Suppl 1):S1–S5 normal value on CT) and[16 mm (two standard deviations below the mean of 20 mm). Results: 100 scans in 79 patients (21 bilateral) were included in this study. The average age of the patients was 29 years, 60 (78 %) females and 19 (22 %) males. The mean TT-PCL distance was 20.16 mm (SD 3.19; 10.11 mm-28.32 mm). The inter-observer (ICC = 0.920) and intra-observer(ICC = 0.983 and 0.993) reliability were both considered excellent. Overall 14 (14 %; Mean = 25.44 mm; SD 1.06) of patients had an abnormal TT-PCL (considered to be [24 mm). 24 (24 %) patients had a TT-TG [ 16 mm, while 16 (16 %) had a TT-TG [ 20 mm. In these groups 8 (33.3 %) and 4 (25 %) of patients had a TTPCL [ 24 mm. Of the 14 patients with an abnormal TT-PCL, 7 (50 %) had a normal TT-TG. Conclusions: An excellent interobserver and intraobserver reliability can be achieved for the TT-PCL measurement. Based on our results only 25–33 % of patients with an abnormal TT-TG had lateralisation of the tibial tubercle in relation to the posterior cruciate ligament. This varies significantly from the previous the incidence of 57 % as described by Seitlinger et al. [1]. Based on these results we suggest that more work is required to define the normal TT-PCL distance and its role in the assessment of patients with patellar instability. [1] Seitlinger G, Scheurecker G, Hogler R, Labey L, Innocenti B, Hofmann S A New Measurement to Define the Position of theTibial Tubercle in Patients With Patellar Dislocation 2012 TT-TG, MRI, TT-PCL.
AW11-2529 The Potential Impact of Repair of the Anterolateral Ligament on Post-ACL Reconstruction Uncontrolled Internal Rotation Branch T.*1, Stinton S.2 1 University Orthopaedic Clinic, Decatur, United States; 2 ArthroMetrix, Chamblee, United States Objectives: The uncontrolled increase in internal rotation after ACL reconstruction has been attributed to a previously unrecognized injury of the newly described ‘anterolateral ligament’. Pearle and others have demonstrated that excessive internal rotation can contribute increased anterior translation to the lateral compartment of the knee, which is key to the symptomatic pivot shift. We hypothesized that theoretical repair of the ‘anterolateral ligament’, thereby reducing excessive internal rotation, would have a statistically significant reduction in anterior translation of the lateral tibial plateau (LTP) in a population of patients with unilateral ACL reconstructions. Methods: 101 patients with one unilateral ACL reconstruction (ACLR) and one healthy knee were consented to participate in this study. Patients were positioned supine within the RKT with knees in 30° of flexion and both feet attached to footplates on the RKT. During testing, motors moved the tibias in one direction until a specified torque threshold was reached and then turned around and continued until the threshold was reached in the other direction. Following 3 preconditioning cycles of each motion, 3 test cycles were performed and tibial kinematics were recorded using electromagnetic markers. The load deformation curves for the 3 classic laxity tests, Anterior/ Posterior Translation, Varus/Valgus Rotation and Internal/External TibialRotation (Dial Test) were analyzed. Maximum Internal Rotation (maxIR), Anterior Translation (maxAT) and Center of Tibial Rotation (COTR) were identified. Patients with increased side-to-side IR in the repaired knee had the COTR and maxIR used to calculate the IR contribution to anterior translation of the LTP. This translation was subtracted from the maxAT to show the potential effect of repair of the ‘anterolateral ligament’. Results: Forty-three percent of the ACL reconstructed population had demonstrated increased tibial internal rotation in the repaired knee
Knee Surg Sports Traumatol Arthrosc (2014) 22 (Suppl 1):S1–S5 versus their healthy knee. The mean anterior translation of the LTP contributed by excessive IR in this subset of patients was 1.58 mm (0.02–6.29). By subtracting the impact of this increased internal rotation on anterior translation of the LTP, the side-to-side difference distribution moved closer towards the healthy knee by 0.69 mm (0–6.29) (p \ 0.0001). Conclusions: The most important finding in this study is that uncontrolled post-ACLR excessive internal rotation contributes
S5 significantly to anterior translation of the lateral tibial plateau in the knee. Anterior cruciate ligament reconstruction alone was unable to control this increased internal rotation. The ‘anterolateral ligament’ has been described as an extra-articular constraint to internal rotation. Reconstruction or repair of the anterolateral ligament may have an additive impact on knee stability. Anterolateral ligament, knee stability, ACL reconstruction.
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Star Paper Session AW11-1129 Extra-articular reconstruction and Pivot shift: ‘‘in vivo’’ dynamic evaluation with navigation Monaco E.*1, Maestri B.1, Mazza D.1, Iorio C.1, Ferretti A.1 1 University of Rome La Sapienza, Sant’Andrea Hospital, Rome, Italy Objectives: The pivot shift is considered the most reliable test used to evaluate the results of the ACL reconstruction as it strongly correlates with the satisfaction of the patient, giving way episodes and activity level. The purpose of this paper is to biomechanically investigate the effect of intra-articular and extra-articular reconstructions on the pivot shift phenomenon as evaluated by navigation. Methods: Twenty patients underwent anatomic single bundle ACL reconstruction with doubled semitendinosus and gracilis tendons with the addition of extra-articular reconstruction as described by CokerArnold (modification of the MacIntosh procedure). The patients were randomized into two groups. In group A, the intra-articular reconstruction was performed first and then the lateral tenodesis was fixed; in group B, the protocol was reversed. The navigation system used was the 2.2 OrthoPilot ACL (B. Braun-Aesculap, Tuttlingen, Germany). The actual version of the software allows the system not only to statically calculate manual maximum anterior tibial translation (ATT) and manual maximum internal rotation (IR) and external rotation (ER) at different degrees of knee flexion but also to dynamically evaluate ATT ad rotation during the Pivot shift test. Measurements were performed before the reconstruction, after the first procedure and after the second procedure in each patient. Results: Static evaluation: The ACL reconstruction is more effective than lateral tenodesis in significantly reducing AP translation (p = 0.03); the addition of the lateral tenodesis to the ACL reconstruction is statistically more effective than the addition of the ACL to the lateral tenodesis in reducing the rotation (p = 0.0025); the addition of the ACL reconstruction to the lateral tenodesis is statistically more effective than the addition of the lateral tenodesis to the ACL reconstruction in reducing the AP translation (p = 0.002). Dynamic evaluation (Pivot shift test): The intra-articular ACL reconstruction alone is as effective as lateral tenodesis alone in reducing post op AP translation and rotation during the Pivot shift; the addition of the lateral tenodesis to the ACL reconstruction is statistically more effective than the addition of the ACL reconstruction to the lateral tenodesis in reducing the rotation during the pivot-shift (p = 0.0146). Conclusions: The extra-articular reconstruction has no effect in reducing the anterior displacement of the tibia at 30° of flexion (Lachman test) but it is more effective than intra-articular reconstruction in reducing tibial rotation in a static condition. Anatomic ACL reconstruction and lateral tenodesis are synergic in controlling pivot shift phenomenon in a dynamic condition and seems to be biomechanically justified in a clinical setting to reduce the Pivot shift phenomenon. ACL, extra-articular reconstruction, pivot-shift, navigation.
AW11-1375 Platelet-rich plasma injections in acute hamstring muscle injuries: a randomised controlled trial Reurink G.*1, Goudswaard G.2, Moen M.3, Weir A.2, Verhaar J.1, Bierma-Zeinstra S.1, Maas M.4, Tol J.2 1 Erasmus Medical Centre, Rotterdam, Netherlands; 2Aspetar Orthpedic and Sports Medicine hospital, Doha, Qatar; 3Bergman Clinics, Naarden, Netherlands; 4Academic Medical Centre, Amsterdam, Netherlands Objectives: Platelet-rich plasma (PRP) injection, derived from autologous blood, is an innovative treatment method that is used worldwide in acute muscle injuries, which are the most prevalent time loss injuries with a high recurrence rate and an enormous financial burden in professional sports. The hamstrings are the most commonly injured muscles. The increasing interest in PRP is emphasized by the rapidly growing global PRP market, which is estimated to triple from 2009 to 2016. After the World Anti-Doping Agency allowed intramuscular applications of PRP in 2011, its use in muscle injuries has been increasing ever since. Basic science in animal models showed that PRP has regenerative effects on muscle tissue, but evidence from high quality clinical studies is lacking. We examined whether PRP injections would be efficacious in acute hamstring muscle injuries. This is the first double-blind, randomised, placebo-controlled trial on the efficacy of PRP in acute muscle injuries. Methods: In three Sports Medicine clinics we included 80 athletes with acute hamstring muscle injuries, confirmed on MRI. We randomised the patients to PRP (PRP-group) or isotonic saline injections (placebo-group). Patients received two injections: at inclusion within 5 days after injury and the second injection five to 7 days after the first. The researchers and the patients were blinded to the content of the syringe. To ensure blinding we prepared a PRP and a placebo syringe for each patient. Both groups undertook a standardized criteria-based rehabilitation program, supervised by a physiotherapist. The primary outcome measure was the time needed to return to play during 6 months follow-up, analysed with a Cox proportionalhazards model. Secondary outcome measures were: Re-injuries within 2 months after return to play, perceived recovery, patient satisfaction, hamstring force, hamstring flexibility and hamstring function measured with the Hamstring Outcome Score. Results: Mean age of the patients was 29 ± 7 years and the majority played soccer (71 %) or field hockey (15 %) on a competitive level (74 %). There were no patients lost to follow-up for the primary outcome analysis. The median time to return to play was 42 days (interquartile range, 30–58) in the PRP-group, as compared to 42 days (interquartile range, 37–56) in the placebo-group (hazard ratio, 0.96; 95 % CI 0.61–1.51: p = 0.66). The re-injury rate was 16 % in the PRP-group and 14 % in the placebo-group (Odds ratio 1.17; 95 % CI 0.33–4.18: p = 0.814). There were also no significant differences on the other secondary outcome measures. Conclusions: We found no benefit of intramuscular PRP injections compared to isotonic saline injections in patients with acute hamstring injuries. Platelet-rich plasma, muscle injury, injection, hamstring.
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S2 AW11-1427 A novel synthetic meniscus implant for the treatment of middle aged patients: Results of 118 patients in a prospective, multicenter study Condello V.*1, Arbel R.2, Agar G.3, Rozen N.4, Angele P.5, Victor J.6, Brittberg M.7, Verdonk P.8 1 Sacro Cuore Don Calabria Hospital, Sports Medicine and Arthroscopic Surgery, Negrar (Verona), Italy; 2Tel Aviv Souraski Medical Center, Sports Medicine and Arthroscopic Surgery, Tel Aviv, Israel; 3Asafh Harofe Medical Center, Beer Jacob, Israel; 4 Emek Medical Center, Afula, Israel; 5Klinikum der Universita¨t Regensburg, Unfallchirurgie, Regensburg, Germany; 6Ghent University Hospital, Orthopaedic Surgery and Traumatology, Gent, Belgium; 7Gothenburg University, Gothenburg, Sweden; 8Antwerp Orthopedic Center, Monica Hospitals, Antwerp, Belgium Objectives: This study aims to evaluate short-term clinical and MRI outcomes of a non-anchored polycarbonate-urethane meniscus implant for medial knee pain in middle-aged patients (Fig. 1). In the younger population, surgical options e.g., allografts and artificial scaffolds are available and have been shown to be effective. For middle-aged patients, the clinical benefit from surgical intervention of a degenerated meniscus has only been reported in a fraction of cases. These patients are too young for more aggressive treatments such as UKA or TKA. This paper presents the first clinical results of a multicenter study, after a minimum of 1 year follow-up. Methods: 118 patients (age 30–73) were treated. All of the patients reported medial knee pain which was associated with either a severely degenerated and non-functional meniscus (18 %) or post-meniscectomy knee pain with grade II-III degenerative changes (Outerbridge) of the medial cartilage (82 %). Patients with grade IV medial cartilage loss or instability were excluded. Primary clinical outcome was measured by the KOOS scale up to 24 months, with secondary outcomes measured by IKDC subjective and VAS questionnaires for pain. Serial MRI scans were taken at 6 weeks, 12- and 24-month follow-up to evaluate the condition of the articular cartilage.
Fig. 1 The medial meniscus implant as located between the medial condyle and the tibia plateau in a curb created by the remaining meniscal rim
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Fig. 2 The results of subjective pain questionnaires a KOOS, and b VAS, as reported by patients implanted with the meniscus implant over 2 years (n = 118 at the baseline, n = 104 at 6 weeks, n = 91 at 6 months, n = 61 at 1 year, and n = 13 at 2 years)
Results: Patients showed a considerable clinical improvement after implantation. Specifically, KOOS Pain and Pain VAS scores were improved by *60 % (p \ 0.05), after 6, 12 and 24 months follow up (Fig. 2), and patient activity levels also were found to increase following implantation. The first MRI findings can be considered promising, with no signs of cartilage deterioration in the majority of the patients. Main complications so far include 11 cases (9.3 %) of either a dislocation and/or fracture of the device. These were mainly due to implantation of a too small implant and/or patients with high BMI or high level of post-op activity. In five cases (4.2 %), not removing enough of the posterior or anterior horns causes subluxation. Three cases of operation- room infection, two cases of re-sizing, four cases of stiff joint and three cases of transient squeak knee were observed. Conclusions: This study was designed to evaluate and obtain assurance of the safety and efficacy ratio of a novel medial meniscus implant in the treatment of a challenging patient cohort. Short-term outcomes are promising and long-term results are ongoing. Knee, polycarbonate-urethane, prosthesis, join replacement. NUsurface Study Group (Alphabetical order): Agar G, MD, Israel Arbel R, MD, Israel Beer Y, MD, Israel Ben-Haim T, MD, Israel Blumberg N, MD, Israel Condello V, MD, Italy Hershman E, MD, USA Prof. Rozen N, MD, PhD, Israel Van Der Straeten, MD, PhD, Belgium Prof. Verdonk P, MD, PhD, Belgium Prof. Verdonk R, MD, PhD, Belgium
Knee Surg Sports Traumatol Arthrosc (2014) 22 (Suppl 1):S1–S5 Prof. Victor J, MD, PhD, Belgium Israeli S, MD, Israel Prof. Angele P, MD, PhD, Germany Zellner J, MD, Germany A Weiler, MD, Berlin, Germany Prof. Brittberg M, MD, PhD, Sweden Shabshin N, MD, Israel Prof. Zorzi C, MD, Italy AW11-1635 Long-term degradation of poly-lactide co-glycolide/betatricalcium phosphate biocomposite anchors in arthroscopic Bankart repair. A prospective study Compagnoni R.*1, Ragone V.1, Aliprandi A.1, Carminati S.1, Bruno V.1, Randelli P.1 1 Policlinico San Donato, San Donato Milanese, Italy Objectives: To evaluate, using MR, the biological efficacy of anchors made of 30 % tricalcium phosphate and 70 % poly-lactic-co-glycolide (PLGA) used for the repair of Bankart lesion following shoulder instability. Methods: Twenty consecutive patients who were candidates for surgical treatment of unidirectional, post- traumatic shoulder instability were treated arthroscopically with anchors made of 70 % PLGA + 30 % beta- tricalcium phosphate preloaded with OrthoCord sutures. Fifteen of them were evaluated by MR at least 16 months after the intervention. A second evaluation was performed at least 12 months after the first in the patients (N = 5) in whom implanted anchors were still visible at the first evaluation with a low intensity signal in all sequences. Two radiologists, with different experience (15 and 3 years), separately evaluated the MR patterns of the trabecular glenoid bone, the walls of the bone tunnel and the signal from the anchors. The following parameters were considered in the MR evaluation: integrity of the tunnel edge (grade 0–2), the intensity of the signal from the anchor site (grade 1–3) and cystic lesions. The normal signal from the glenoid trabecular bone has been used as the reference parameter. The anchors were considered independent variables and so each one was analysed individually, even in the same patient. At the final clinical follow-up, a ROWE questionnaire was filled in for each patient. Results: Overall, 44 anchors were evaluated (33 anchors in the first +11 anchors in the second follow-up). The mean follow-up was 28.6 months. Except for two patients (10 %) none of the other patients had any episodes of dislocation. No cystic lesions were detected by MR imaging. The interobserver concordance between the two radiologists calculated with Khoen’s k was substantial (k = 0,780 and k = 0,791 for integrity of the tunnel edge and for intensity of the signal from the anchor site respectively). Both the integrity of the tunnel border and the intensity of the signal in the site of anchors that had been implanted more than 24 months prior to the evaluation were significantly different from those of anchors implanted less than 24 months (tunnel border grade, 0: 41 %, 1: 50 %, 2: 9 % vs 0: 4.5 %; 1: 50 %; 2: 45.5 %, p = 0.003; anchor signal grade, 1: 41 %, 2: 45.5 %, 3: 13.5 % vs 1: 13.5 %; 2: 41 %; 3: 45.5 %, p = 0.03). Analysis of the linear contrasts (ANOVA) showed a linear increase in the mean values of the times to increased tunnel border grade (grade 0: 22 ± 4 months; grade 1: 27 ± 8 months; grade 2: 29 ± 5 months; p = 0.02) and grade of intensity of the signal in the anchor site (grade 1: 24 ± 6 months; grade 2: 26 ± 7 months; grade 3: 29 ± 7 months; p = 0.05). Conclusions: Anchors made of 30 % b-tricalcium phosphate and 70 % PLGA did, therefore, show excellent biological efficacy, without causing significant cystic lesion, producing gradual changes in the MR signal that seems to became equivalent to that of the glenoid trabecular bone in a mean time of 29 months after implantation. Shoulder instability.
S3 AW11-1964 Comparison of Glenohumeral Contact Pressures and Contact Areas After Posterior Glenoid Reconstruction With Iliac Crest or Distal Tibia Osteochondral Allograft Frank R.*1, Shin J.2, Saccomanno M.3, Provencher M.4, Romeo A.1, Verma N.1 1 Rush University Medical Center, Department of Orthopaedic Surgery, Chicago, United States; 2University of Saskatchewan, Royal University Hospital, Saskatoon, Canada; 3Catholic University, Department of Orthopaedic Surgery, Rome, Italy; 4Harvard University, Massachusetts General Hospital, Boston, United States Objectives: While offering the same benefit of posterior shoulder stabilization, posterior glenoid reconstruction with distal tibia allograft offers the theoretical advantage of improved joint congruity and a cartilaginous articulation with the humeral head over iliac crest reconstruction. To evaluate glenohumeral contact areas, contact pressures, and peak forces in (1) the intact glenoid and after (2) 20 % posterior glenoid surface area defect from 6 o’clock to 10 o’clock (right shoulder), (3) 20 % glenoid defect with flush posterior bone block graft with ICBG; and (4) 20 % glenoid defect with DTA. The hypothesis was that reconstruction with DTA would more effectively restore normal glenoid contact pressures (CP), contact areas (CA), and peak forces (PF) when compared to the deficient glenoid. Methods: Eight fresh-frozen human cadaveric shoulders were randomly tested in four conditions as follows: (1) intact glenoid, (2) 20 % posterior-inferior glenoid surface area defect, (3) 20 % defect reconstructed with flush ICBG; and (4) 20 % defect reconstructed with fresh DTA. A Materials Testing System was used to apply a compressive load of 440-N for each condition in the following clinically relevant arm positions: (1) neutral (scapular plane), (2) 60° humeral abduction, and (3) 90° flexion-45° internal rotation (FIR). Results: Glenoid reconstruction with DTA resulted in significantly higher CA compared to the 20 % defect model in neutral (4.40 ± 0.97 vs 3.66 ± 0.50 cm2, respectively) and 60° (4.80 ± 0.73 vs 3.80 ± 0.50 cm2, respectively). There were no differences in the CA between ICBG and the 20 % defect state in either the neutral or 60° positions. The intact state exhibited significantly higher CA than the defect (p \ 0.01) and ICBG (p \ 0.05) in all positions. Reconstruction with both DTA and ICBG resulted in significantly lower CP compared to the defect state at 60° of abduction (4.14 ± 0.97 vs 4.19 ± 0.95 vs 4.51 ± 1.11 kg/cm2, respectively). Reconstruction with DTA resulted in lower PF compared to ICBG in all positions (neutral, 60°, and FIR). Conclusions: Reconstruction of posterior glenoid bone defects with DTA may allow for improved joint congruity with higher CA and lower PF within the glenohumeral joint than ICBG reconstruction. While these mechanical properties may translate into clinical differences, further studies are needed to understand their effects. Shoulder instability, posterior glenoid, glenoid bone defect, distal tibia allograft.
AW11-2426 Metal resurfacing inlay implant for osteochondral defects of the talus after failed previous surgery: a prospective study van Bergen C.*1, van Eekeren I.2, Reilingh M.1, Gerards R.1, Sierevelt I.3, van Dijk C.4 1 Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands; 2Academic Medical Center Amsterdam, Orthopedic Surgery, Amsterdam, Netherlands; 3Slotervaart Hospital, Dept. of Orthopaedic Surgery, Amsterdam, Netherlands; 4Academisch Medisch Centrum, University of Amsterdam, Amsterdam, Netherlands Objectives: Osteochondral ankle defects (OCDs) mainly occur in a young, active population. In 63 % of cases the defect is located on the medial talar dome. Arthroscopic debridement and microfracture is
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S4 considered the primary treatment for defects up to 15 mm. To treat patients with a secondary OCD of the medial talar dome and avoid donor site morbidity, a 15-mm diameter metal resurfacing inlay implant was developed. The present study aimed to evaluate the clinical effectiveness of the metal implant for OCDs of the medial talar dome. Methods: We prospectively studied 22 consecutive patients for a mean of 3 years and 4 months (range, 2–5 years). We included patients with an OCD of the medial talar dome, with the largest diameter being between 12 mm and 20 mm as measured on CT scans. For inclusion patients had to have complained persistently for more than a year after previous surgical treatment. Exclusion criteria included an age \ 18 years, ankle osteoarthritis grade III, other ankle pathology, and diabetes mellitus. The primary outcome measure was the Numeric Rating Scale of pain (NRS) at rest and during walking, running, and stair climbing. Secondary outcome measures were the Foot Ankle Outcome Score (FAOS), American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Short-Form 36 (SF-36) and radiographic evaluation. Results: There was statistically significant reduction of the NRS pain in each of four situations (p \ 0.01; repeated measures ANOVA). For example, the NRS during walking improved from a mean of 6.7 ± 1.2 preoperatively to 3.4 ± 2.9 at final follow-up. The FAOS improved on all subscales (p \ 0.03; repeated measures ANOVA). The AOFAS score improved from a median of 62 (range, 28–75) preoperatively to 82 (range, 46–100) at final follow-up (p \ 0.01; Friedman’s two-way analysis of variance by ranks). The SF-36 physical component scale improved from a mean of 36 ± 8 pre-operatively to 48 ± 15 at final follow-up (p \ 0.01; repeated measures ANOVA); the mental component scale did not change significantly. On radiographs, degenerative changes were observed in four patients. One patient required additional surgery for the OCD. Conclusions: This study shows that a metal implant is a promising treatment for OCDs of the medial talar dome after failed previous surgery.
AW11-2436 The Tibial Tubercle—Posterior Cruciate Ligament Distance: An independent review of this new measurement Anley C.*1, Saithna A.1, Morris G.1, James S.1, Snow M.1 1 Royal Orthopaedic Hospital, Birmingham, United Kingdom Objectives: The Tibial Tubercle-Trochlear Grove (TT-TG) distance is commonly used to assess patellar mal- alignment, however measuring the TT-TG in patients with trochlear dysplasia can be inaccurate due to the absence of landmarks. To obviate these factors, Seitlinger et al. [1] have recently suggested a new measurement to assess the position of the tibial tubercle in patients with anterior knee pain, namely the Tibial Tubercle- Posterior Cruciate Ligament Distance (TT-PCL). The TT-PCL distance is the mediolateral distance between the midpoint of the insertion of the patellar tendon and the medial border of the posterior cruciate ligament parallel to the dorsal tibia condylar line [1]. In their study they concluded this was a reliable measurement and that the normal TT-PCL was \24 mm. The aim of our study was to independently assess the interobserver and intraobserver reliability of this measurement and in addition to asses the incidence of true lateralization of the tibial tubercle in our study population. Methods: The magnetic resonance imaging (MRI) scans of 100 knees, with patellar pathology, were identified. The TT-PCL was measured according to the method originally described by Seitlinger et al. Measurements where preformed independently by two fellowship trained orthopaedic surgeons. Twenty measurements where repeated on a separate occasion to allow for an assessment of the intra-rater reliability. Inter-observer and intra- observer reliability was evaluated via the intra-class correlation coefficient. The results of the TT-PCL distance were examined in patients with an abnormal TT-TG based on two values, [20 mm (accepted
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Knee Surg Sports Traumatol Arthrosc (2014) 22 (Suppl 1):S1–S5 normal value on CT) and[16 mm (two standard deviations below the mean of 20 mm). Results: 100 scans in 79 patients (21 bilateral) were included in this study. The average age of the patients was 29 years, 60 (78 %) females and 19 (22 %) males. The mean TT-PCL distance was 20.16 mm (SD 3.19; 10.11 mm-28.32 mm). The inter-observer (ICC = 0.920) and intra-observer(ICC = 0.983 and 0.993) reliability were both considered excellent. Overall 14 (14 %; Mean = 25.44 mm; SD 1.06) of patients had an abnormal TT-PCL (considered to be [24 mm). 24 (24 %) patients had a TT-TG [ 16 mm, while 16 (16 %) had a TT-TG [ 20 mm. In these groups 8 (33.3 %) and 4 (25 %) of patients had a TTPCL [ 24 mm. Of the 14 patients with an abnormal TT-PCL, 7 (50 %) had a normal TT-TG. Conclusions: An excellent interobserver and intraobserver reliability can be achieved for the TT-PCL measurement. Based on our results only 25–33 % of patients with an abnormal TT-TG had lateralisation of the tibial tubercle in relation to the posterior cruciate ligament. This varies significantly from the previous the incidence of 57 % as described by Seitlinger et al. [1]. Based on these results we suggest that more work is required to define the normal TT-PCL distance and its role in the assessment of patients with patellar instability. [1] Seitlinger G, Scheurecker G, Hogler R, Labey L, Innocenti B, Hofmann S A New Measurement to Define the Position of theTibial Tubercle in Patients With Patellar Dislocation 2012 TT-TG, MRI, TT-PCL.
AW11-2529 The Potential Impact of Repair of the Anterolateral Ligament on Post-ACL Reconstruction Uncontrolled Internal Rotation Branch T.*1, Stinton S.2 1 University Orthopaedic Clinic, Decatur, United States; 2 ArthroMetrix, Chamblee, United States Objectives: The uncontrolled increase in internal rotation after ACL reconstruction has been attributed to a previously unrecognized injury of the newly described ‘anterolateral ligament’. Pearle and others have demonstrated that excessive internal rotation can contribute increased anterior translation to the lateral compartment of the knee, which is key to the symptomatic pivot shift. We hypothesized that theoretical repair of the ‘anterolateral ligament’, thereby reducing excessive internal rotation, would have a statistically significant reduction in anterior translation of the lateral tibial plateau (LTP) in a population of patients with unilateral ACL reconstructions. Methods: 101 patients with one unilateral ACL reconstruction (ACLR) and one healthy knee were consented to participate in this study. Patients were positioned supine within the RKT with knees in 30° of flexion and both feet attached to footplates on the RKT. During testing, motors moved the tibias in one direction until a specified torque threshold was reached and then turned around and continued until the threshold was reached in the other direction. Following 3 preconditioning cycles of each motion, 3 test cycles were performed and tibial kinematics were recorded using electromagnetic markers. The load deformation curves for the 3 classic laxity tests, Anterior/ Posterior Translation, Varus/Valgus Rotation and Internal/External TibialRotation (Dial Test) were analyzed. Maximum Internal Rotation (maxIR), Anterior Translation (maxAT) and Center of Tibial Rotation (COTR) were identified. Patients with increased side-to-side IR in the repaired knee had the COTR and maxIR used to calculate the IR contribution to anterior translation of the LTP. This translation was subtracted from the maxAT to show the potential effect of repair of the ‘anterolateral ligament’. Results: Forty-three percent of the ACL reconstructed population had demonstrated increased tibial internal rotation in the repaired knee
Knee Surg Sports Traumatol Arthrosc (2014) 22 (Suppl 1):S1–S5 versus their healthy knee. The mean anterior translation of the LTP contributed by excessive IR in this subset of patients was 1.58 mm (0.02–6.29). By subtracting the impact of this increased internal rotation on anterior translation of the LTP, the side-to-side difference distribution moved closer towards the healthy knee by 0.69 mm (0–6.29) (p \ 0.0001). Conclusions: The most important finding in this study is that uncontrolled post-ACLR excessive internal rotation contributes
S5 significantly to anterior translation of the lateral tibial plateau in the knee. Anterior cruciate ligament reconstruction alone was unable to control this increased internal rotation. The ‘anterolateral ligament’ has been described as an extra-articular constraint to internal rotation. Reconstruction or repair of the anterolateral ligament may have an additive impact on knee stability. Anterolateral ligament, knee stability, ACL reconstruction.
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