Fixation strength of biocomposite wedge interference screw in ACL reconstruction: effect of screw length and tunnel/screw ratio. A controlled laboratory study

<p>Abstract</p> <p>Background</p> <p>Primary stability of the graft is essential in anterior cruciate ligament surgery. An optimal method of fixation should be easy to insert and provide great resistance against pull-out forces.</p> <p>A controlled laboratory study was designed to test the primary stability of ACL tendinous grafts in the tibial tunnel. The correlation between resistance to traction forces and the cross-section and length of the screw was studied.</p> <p>Methods</p> <p>The tibial phase of ACL reconstruction was performed in forty porcine tibias using digital flexor tendons of the same animal. An 8 mm tunnel was drilled in each specimen and two looped tendons placed as graft. Specimens were divided in five groups according to the diameter and length of the screw used for fixation. Wedge interference screws were used. Longitudinal traction was applied to the graft with a Servohydraulic Fatigue System. Load and displacement were controlled and analyzed.</p> <p>Results</p> <p>The mean loads to failure for each group were 295,44 N (Group 1; 9 × 23 screw), 564,05 N (Group 2; 9 × 28), 614,95 N (Group 3; 9 × 35), 651,14 N (Group 4; 10 × 28) and 664,99 (Group 5; 10 × 35). No slippage of the graft was observed in groups 3, 4 and 5. There were significant differences in the load to failure among groups (ANOVA/P < 0.001).</p> <p>Conclusions</p> <p>Longer and wider interference screws provide better fixation in tibial ACL graft fixation. Short screws (23 mm) do not achieve optimal fixation and should be implanted only with special requirements.</p

Stress fractures of the femoral shaft in women's college lacrosse: a report of seven cases and a review of the literature

Background: Stress fractures do not often occur in the shaft of the femur. They are more common in the femoral neck, the tibial shaft, the metatarsals, and other bones of the foot. In female athletes, stress fractures classically afflict the distance runner, the ballerina, the gymnast, and the figure skater. Objectives: To describe the clinical presentation, diagnosis, treatment, and outcome of seven college female lacrosse players with femoral shaft stress fractures, and review the literature. Results: The unusual results of this study support the principle that clinical suspicion should be high when treating any female athlete regardless of the sport. In this case series, an abrupt change in the quality of the running surface during the competitive training season was the only underlying common thread among the athletes. Conclusion: The findings suggest that risk factors for the female athlete are variable and are no longer limited to the undernourished or overtrained

Evaluation of Graft Tensioning Effects in Anterior Cruciate Ligament Reconstruction between Hamstring and Bone–Patellar Tendon Bone Autografts

AbstractThis article investigates the clinical, functional, and radiographic outcomes in anterior cruciate ligament (ACL) reconstruction patients over 7 years to determine the effects of initial graft tension on outcomes when using patellar tendon (bone–tendon–bone [BTB]) and hamstring tendon (HS) autografts. Ninety patients, reconstructed with BTB or HS, were randomized using two initial graft tension protocols: (1) normal anteroposterior (AP) laxity (“low-tension”; n = 46) and (2) AP laxity overconstrained by 2 mm (“high-tension”; n = 44). Seventy-two patients had data available at 7 years, with 9 excluded for graft failure. Outcomes included the Knee Injury and Osteoarthritis Outcome Score, Short-Form-36 (SF-36), and Tegner activity scale. Clinical outcomes included KT-1000S and International Knee Documentation Committee examination score; and functional outcomes included 1-leg hop distance and peak knee extensor torque. Imaging outcomes included medial joint space width, Osteoarthritis Research Society International radiographic score, and Whole-Organ Magnetic Resonance Score. There were significantly improved outcomes in the high-tension compared with the low-tension HS group for SF-36 subset scores for bodily pain (p = 0.012), social functioning (p = 0.004), and mental health (p = 0.014) 84 months postsurgery. No significant differences in any outcome were found within the BTB groups. Tegner activity scores were also significantly higher for the high-tension HS group compared with the low-tension (6.0 vs. 3.8, p = 0.016). Patients with HS autografts placed in high tension had better outcomes relative to low tension for Tegner activity score and SF-36 subset scores for bodily pain, social functioning, and mental health. For this reason, we recommend that graft fixation be performed with the knee at 30-degree flexion (“high-tension” condition) when reconstructing the ACL with HS autograft.</jats:p

Preoperative KOOS and SF-36 Scores Are Associated With the Development of Symptomatic Knee Osteoarthritis at 7 Years After Anterior Cruciate Ligament Reconstruction

Background: Anterior cruciate ligament (ACL) tears are associated with the development of knee osteoarthritis despite ACL reconstruction surgery. However, little evidence is available to determine which patients will develop symptomatic knee osteoarthritis. Purpose: To determine if preoperative outcome measures—KOOS (Knee injury and Osteoarthritis Outcome Score) and SF-36 (36-item Short Form Health Survey)—were associated with the development of a symptomatic knee 7 years after ACL reconstruction. A secondary goal was to examine the relationship between imaging evidence of knee osteoarthritis and development of knee pain. Study Design: Case-control study; Level of evidence, 3. Methods: Prospectively collected data from 72 patients were reviewed with 7-year follow-up after unilateral ACL reconstruction. Patients were divided into symptomatic and asymptomatic groups based on the previously defined KOOS pain ≤72. Demographic variables and preoperative KOOS and SF-36 scores were compared between groups. Radiographic and magnetic resonance imaging data were used to evaluate differences in joint space width, Osteoarthritis Research Society International radiographic score, and the Whole-Organ Magnetic Resonance Imaging Score between groups. Univariate and multivariate analyses were performed to identify potential predictors of pain at 7-year follow-up. Wilcoxon sum rank and t tests were used to compare imaging findings between the symptomatic and asymptomatic patients at 7 years. Results: According to KOOS pain, 7 of the 72 patients available at 7-year follow-up formed the symptomatic group. No differences were found between groups in regard to demographic variables or intraoperative findings. In multivariate analysis, lower preoperative scores for KOOS sports/recreation ( P = .005) and SF-36 mental health ( P = .025) were associated with a painful knee at 7 years, with increased odds of 82% and 68% per 10-unit decrease, respectively. The Whole-Organ Magnetic Resonance Imaging Score at 7 years showed evidence of osteoarthritic changes in the symptomatic group as compared with the asymptomatic group ( P = .047). However, there were no significant differences in the Osteoarthritis Research Society International radiographic score ( P = .051) or joint space width ( P = .488) between groups. Conclusion: Lower preoperative KOOS and SF-36 scores were associated with those patients who developed symptomatic knee osteoarthritis 7 years after ACL reconstruction. </jats:sec

DS_10.1177_0363546518823556 – Supplemental material for Anatomic Features of the Tibial Plateau Predict Outcomes of ACL Reconstruction Within 7 Years After Surgery

Supplemental material, DS_10.1177_0363546518823556 for Anatomic Features of the Tibial Plateau Predict Outcomes of ACL Reconstruction Within 7 Years After Surgery by Ata M. Kiapour, Daniel S. Yang, Gary J. Badger, Naga Padmini Karamchedu, Martha M. Murray, Paul D. Fadale, Michael J. Hulstyn, Robert M. Shalvoy and Braden C. Fleming in The American Journal of Sports Medicine</p