Performance of 5-Strand Hamstring Autograft Anterior Cruciate Ligament Reconstruction in the STABILITY Study: A Subgroup Analysis.

BACKGROUND: Anterior cruciate ligament (ACL) reconstructions (ACLRs) with graft diameters <8mm have been shown to have higher revision rates. The 5-strand (5S) hamstring autograft configuration is a proposed option to increase graft diameter. PURPOSE: To investigate the differences in clinical outcomes between 4-strand (4S) and 5S hamstring autografts for ACLR in patients who underwent ACLR alone or concomitantly with a lateral extra-articular tenodesis (LET) procedure. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Data from the STABILITY study were analyzed to compare a subgroup of patients undergoing ACLR alone or with a concomitant LET procedure (ACLR + LET) with a minimum graft diameter of 8mm that had either a 4S or 5S hamstring autograft configuration. The primary outcome was clinical failure, a composite of rotatory laxity and/or graft failure. The secondary outcome measures consisted of 2 patient-reported outcome scores (PROs)-namely, the ACL Quality of Life Questionnaire (ACL-QoL) and the International Knee Documentation Committee (IKDC) score at 24 months postoperatively. RESULTS: Of the 618 patients randomized in the STABILITY study, 399 (228 male; 57%) fit the inclusion criteria for this study. Of these, 191 and 208 patients underwent 4S and 5S configurations of hamstring ACLR, respectively, with a minimum graft diameter of 8mm. Both groups had similar characteristics other than differences in anthropometric factors-namely, sex, height, and weight, and Beighton scores. The primary outcomes revealed no difference between the 2 groups in rotatory stability (odds ratio [OR], 1.19; 95% CI, 0.77-1.84; P = .42) or graft failure (OR, 1.13; 95% CI, 0.51-2.50; P = .76). There was no significant difference between the groups in Lachman (P = .46) and pivot-shift (P = .53) test results at 24 months postoperatively. The secondary outcomes revealed no differences in the ACL-QoL (P = .67) and IKDC (P = .83) scores between the 2 subgroups. CONCLUSION: At the 24-month follow-up, there were no significant differences in clinical failure rates and PROs in an analysis of patients with 4S and 5S hamstring autografts of ≥8mm diameter for ACLR or ACLR + LET. The 5S hamstring graft configuration is a viable option to produce larger-diameter ACL grafts.

Predictors of Graft Failure in Young Active Patients Undergoing Hamstring Autograft Anterior Cruciate Ligament Reconstruction With or Without a Lateral Extra-articular Tenodesis: The Stability Experience.

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction (ACLR) has higher failure rates in young active patients returning to sports as compared with older, less active individuals. Augmentation of ACLR with an anterolateral procedure has been shown to reduce failure rates; however, indications for this procedure have yet to be clearly defined. PURPOSE/HYPOTHESIS: The purpose of this study was to identify predictors of ACL graft failure in high-risk patients and determine key indications for when hamstring ACLR should be augmented by a lateral extra-articular tenodesis (LET). We hypothesized that different preoperative characteristics and surgical variables may be associated with graft failure characterized by asymmetric pivot shift and graft rupture. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Data were obtained from the Stability 1 Study, a multicenter randomized controlled trial of young active patients undergoing autologous hamstring ACLR with or without a LET. We performed 2 multivariable logistic regression analyses, with asymmetric pivot shift and graft rupture as the dependent variables. The following were included as predictors: LET, age, sex, graft diameter, tear chronicity, preoperative high-grade knee laxity, preoperative hyperextension on the contralateral side, medial meniscal repair/excision, lateral meniscal repair/excision, posterior tibial slope angle, and return-to-sports exposure time and level. RESULTS: Of the 618 patients in the Stability 1 Study, 568 with a mean age of 18.8 years (292 female; 51.4%) were included in this analysis. Asymmetric pivot shift occurred in 152 (26.8%) and graft rupture in 43 (7.6%). The addition of a LET (odds ratio [OR], 0.56; 95% CI, 0.37-0.83) and increased graft diameter (OR, 0.62; 95% CI, 0.44-0.87) were significantly associated with lower odds of asymmetric pivot shift. The addition of a LET (OR, 0.40; 95% CI, 0.18-0.91) and older age (OR, 0.83; 95% CI, 0.72-0.96) significantly reduced the odds of graft rupture, while greater tibial slope (OR, 1.15; 95% CI, 1.01-1.32), preoperative high-grade knee laxity (OR, 3.27; 95% CI, 1.45-7.41), and greater exposure time to sport (ie, earlier return to sport) (OR, 1.18; 95% CI, 1.08-1.29) were significantly associated with greater odds of rupture. CONCLUSION: The addition of a LET and larger graft diameter were significantly associated with reduced odds of asymmetric pivot shift. Adding a LET was protective of graft rupture, while younger age, greater posterior tibial slope, high-grade knee laxity, and earlier return to sport were associated with increased odds of graft rupture. Orthopaedic surgeons should consider supplementing hamstring autograft ACLR with a LET in young active patients with morphological characteristics that make them at high risk of reinjury.

Association of Ligamentous Laxity, Male Sex, Chronicity, Meniscal Injury, and Posterior Tibial Slope With a High-Grade Preoperative Pivot Shift: A Post Hoc Analysis of the STABILITY Study.

BACKGROUND: A spectrum of anterolateral rotatory laxity exists in anterior cruciate ligament (ACL)-injured knees. Understanding of the factors contributing to a high-grade pivot shift continues to be refined. PURPOSE: To investigate factors associated with a high-grade preoperative pivot shift and to evaluate the relationship between this condition and baseline patient-reported outcome measures (PROMs). STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A post hoc analysis was performed of 618 patients with ACL deficiency deemed high risk for reinjury. A binary logistic regression model was developed, with high-grade pivot shift as the dependent variable. Age, sex, Beighton score, chronicity of the ACL injury, posterior third medial or lateral meniscal injury, and tibial slope were selected as independent variables. The importance of knee hyperextension as a component of the Beighton score was assessed using receiver operator characteristic curves. Baseline PROMs were compared between patients with and without a high-grade pivot. RESULTS: Six factors were associated with a high-grade pivot shift: Beighton score (each additional point; odds ratio [OR], 1.17; 95% CI, 1.06-1.30; P = .002), male sex (OR, 2.30; 95% CI, 1.28-4.13; P = .005), presence of a posterior third medial (OR, 2.55; 95% CI, 1.11-5.84; P = .03) or lateral (OR, 1.76; 95% CI, 1.01-3.08; P = .048) meniscal injury, tibial slope >9° (OR, 2.35; 95% CI, 1.09-5.07; P = .03), and chronicity >6 months (OR, 1.70; 95% CI, 1.00-2.88; P = .049). The presence of knee hyperextension improved the diagnostic utility of the Beighton score as a predictor of a high-grade pivot shift. Tibial slope <9° was associated with only a high-grade pivot in the presence of a posterior third medial meniscal injury. Patients with a high-grade pivot shift had higher baseline 4-Item Pain Intensity Measure scores than did those without a high-grade pivot shift (mean ± SD, 11 ± 13 vs 8 ± 14; P = .04); however, there was no difference between groups in baseline International Knee Documentation Committee, ACL Quality of Life, Knee injury and Osteoarthritis Outcome Score, or Knee injury and Osteoarthritis Outcome Score subscale scores. CONCLUSION: Ligamentous laxity, male sex, posterior third medial or lateral meniscal injury, increased posterior tibial slope, and chronicity were associated with a high-grade pivot shift in this population deemed high risk for repeat ACL injury. The effect of tibial slope may be accentuated by the presence of meniscal injury, supporting the need for meniscal preservation. Baseline PROMs were similar between patients with and without a high-grade pivot shift.

Lateral Extra-articular Tenodesis Reduces Failure of Hamstring Tendon Autograft Anterior Cruciate Ligament Reconstruction: 2-Year Outcomes From the STABILITY Study Randomized Clinical Trial.

BACKGROUND: Persistent anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR) has been correlated with poor clinical outcomes and graft failure. HYPOTHESIS: We hypothesized that a single-bundle, hamstring ACLR in combination with a lateral extra-articular tenodesis (LET) would reduce the risk of ACLR failure in young, active individuals. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: This is a multicenter, prospective, randomized clinical trial comparing a single-bundle, hamstring tendon ACLR with or without LET performed using a strip of iliotibial band. Patients 25 years or younger with an ACL-deficient knee were included and also had to meet at least 2 of the following 3 criteria: (1) grade 2 pivot shift or greater, (2) a desire to return to high-risk/pivoting sports, (3) and generalized ligamentous laxity (GLL). The primary outcome was ACLR clinical failure, a composite measure of rotatory laxity or a graft rupture. Secondary outcome measures included the P4 pain scale, Marx Activity Rating Scale, Knee injury Osteoarthritis and Outcome Score (KOOS), International Knee Documentation Committee score, and ACL Quality of Life Questionnaire. Patients were reviewed at 3, 6, 12, and 24 months postoperatively. RESULTS: A total of 618 patients (297 males; 48%) with a mean age of 18.9 years (range, 14-25 years) were randomized. A total of 436 (87.9%) patients presented preoperatively with high-grade rotatory laxity (grade 2 pivot shift or greater), and 215 (42.1%) were diagnosed as having GLL. There were 18 patients lost to follow-up and 11 who withdrew (~5%). In the ACLR group, 120/298 (40%) patients sustained the primary outcome of clinical failure, compared with 72/291 (25%) in the ACLR+LET group (relative risk reduction [RRR], 0.38; 95% CI, 0.21-0.52; P < .0001). A total of 45 patients experienced graft rupture, 34/298 (11%) in the ACLR group compared with 11/291 (4%) in the ACL+LET group (RRR, 0.67; 95% CI, 0.36-0.83; P < .001). The number needed to treat with LET to prevent 1 patient from graft rupture was 14.3 over the first 2 postoperative years. At 3 months, patients in the ACLR group had less pain as measured by the P4 (P = .003) and KOOS (P = .007), with KOOS pain persisting in favor of the ACLR group to 6 months (P = .02). No clinically important differences in patient-reported outcome measures were found between groups at other time points. The level of sports activity was similar between groups at 2 years after surgery, as measured by the Marx Activity Rating Scale (P = .11). CONCLUSION: The addition of LET to a single-bundle hamstring tendon autograft ACLR in young patients at high risk of failure results in a statistically significant, clinically relevant reduction in graft rupture and persistent rotatory laxity at 2 years after surgery. REGISTRATION: NCT02018354 ( ClinicalTrials.gov identifier).

Quantitative in vivo assessment of bone microarchitecture in the human knee using HR-pQCT.

OBJECTIVE: High-resolution peripheral quantitative computed tomography (HR-pQCT) is a novel imaging modality capable of visualizing bone microarchitecture in vivo at human peripheral sites such as the distal radius and distal tibia. This research has extended the technology to provide a non-invasive assessment of bone microarchitecture at the human knee by establishing new hardware, imaging protocols and data analysis. DESIGN: A custom leg holder was developed to stabilize a human knee centrally within a second generation HR-pQCT field of view. Five participants with anterior cruciate ligament reconstructions had their knee joint imaged in a continuous scan of 6cm axially. The nominal isotropic voxel size was 60.7µm. Bone mineral density and microarchitecture were assessed within the weight-bearing regions of medial and lateral compartments of the knee at three depths from the weight-bearing articular bone surface, including both the cortical and trabecular bone regions. RESULTS: Scan duration was approximately 18min per knee and produced 5GB of projection data and 10GB of reconstructed image data (2304×2304 image matrix, 1008 slices). Motion during the scan was minimized by the leg holder and was similar in magnitude as a scan of the distal tibia. Bone mineral density and microarchitectural parameters were assessed for 16 volumes of interest in the tibiofemoral joint. CONCLUSIONS: This is a new non-invasive in vivo assessment tool for bone microarchitecture in the human knee that provides an opportunity to gain insight into normal, injured and surgically reconstructed human knee bone architecture in cross-sectional or longitudinal studies.

The incidence of proximal deep vein thrombosis after elective hip arthroscopy: a prospective cohort study in low risk patients.

Prospectively assess the incidence of deep venous thrombosis (DVT) using Doppler Ultrasound, in patients receiving elective hip arthroscopy without pharmacologic/mechanical prophylaxis. One hundred and fifteen consecutive patients (mean 35.4 years, SD = 10.3) underwent elective hip arthroscopy. Patients with previous major risk factors for DVT were excluded. Signs/symptoms of DVT/pulmonary embolism were assessed at 2-week post-operatively. A bilateral whole leg Duplex color (Doppler) Ultrasonography was scheduled between 10- and 22-day post-op. The primary outcome was frequency of DVT. Secondary outcomes assessed surgical risk factors. One hundred and ten patients (mean = 34.3 years, SD = 10.1) did not get a DVT. Five patients (mean = 43.8 years, SD = 12.1) were diagnosed with a DVT, 2- to 22-day post-operatively. All DVT patients received arthroscopy in the supine position (n = 76), versus no patients in the lateral position (n = 39). Average traction time was 38 (SD = 4) and 61 (SD = 4) minutes for patients with and without a DVT, respectively. All other a priori defined risk factors were similar. Four out of five patients presented with symptoms of a DVT, confirmed by ultrasound. One patient was without symptoms/clinical findings. Four patients had a DVT restricted to the calf veins; one patient had involvement of the popliteal vein. No patients had proximal extension into the thigh or pelvis. No pulmonary emboli were suspected or occurred. The incidence of deep venous thromboembolism is 4.3%. The majority of patients had symptomatic and distal venous thromboembolic events. This study provides supportive evidence that routine prophylaxis and/or screening may not be necessary in low risk patients undergoing elective hip arthroscopy.

Complications and Adverse Events of a Randomized Clinical Trial Comparing 3 Graft Types for ACL Reconstruction.

OBJECTIVE: Complications/adverse events of anterior cruciate ligament (ACL) surgery are underreported, despite pooled level 1 data in systematic reviews. All adverse events/complications occurring within a 2-year postoperative period after primary ACL reconstruction, as part of a large randomized clinical trial (RCT), were identified and described. DESIGN: Prospective, double-blind randomized clinical trial. Patients and the independent trained examiner were blinded to treatment allocation. SETTING: University-based orthopedic referral practice. PATIENTS: Three hundred thirty patients (14-50 years; 183 males) with isolated ACL deficiency were intraoperatively randomized to ACL reconstruction with 1 autograft type. Graft harvest and arthroscopic portal incisions were identical. INTERVENTION: Patients were equally distributed to patellar tendon (PT), quadruple-stranded hamstring tendon (HT), and double-bundle (DB) hamstring autograft ACL reconstruction. MAIN OUTCOME MEASURES: Adverse events/complications were patient reported, documented, and diagnoses confirmed. RESULTS: Two major complications occurred: pulmonary embolism and septic arthritis. Twenty-four patients (7.3%) required repeat surgery, including 25 separate operations: PT = 7 (6.4%), HT = 9 (8.2%), and DB = 8 (7.3%). Repeat surgery was performed for meniscal tears (3.6%; n = 12), intra-articular scarring (2.7%; n = 9), chondral pathology (0.6%; n = 2), and wound dehiscence (0.3%; n = 1). Other complications included wound problems, sensory nerve damage, muscle tendon injury, tibial periostitis, and suspected meniscal tears and chondral lesions. Overall, more complications occurred in the HT/DB groups (PT = 24; HT = 31; DB = 45), but more PT patients complained of moderate or severe kneeling pain (PT = 17; HT = 9; DB = 4) at 2 years. CONCLUSIONS: Overall, ACL reconstructive surgery is safe. Major complications were uncommon. Secondary surgery was necessary 7.3% of the time for complications/adverse events (excluding graft reinjury or revisions) within the first 2 years. LEVEL OF EVIDENCE: Level 1 (therapeutic studies). CLINICAL RELEVANCE: This article reports on the complications/adverse events that were prospectively identified up to 2 years postoperatively, in a defined patient population participating in a large double-blind randomized clinical trial comparing PT, single-bundle hamstring, and DB hamstring reconstructions for ACL rupture.

Reruptures, Reinjuries, and Revisions at a Minimum 2-Year Follow-up: A Randomized Clinical Trial Comparing 3 Graft Types for ACL Reconstruction.

OBJECTIVE: To evaluate the predictive factors for traumatic rerupture, reinjury, and atraumatic graft failure of anterior cruciate ligament (ACL) reconstruction at a minimum 2-year follow-up. DESIGN: Double-blind randomized clinical trial (RCT) with intraoperative computer-generated allocation. SETTING: University-based orthopedic referral practice. PATIENTS: Three hundred thirty patients with isolated ACL deficiency were equally randomized to (1) patellar tendon (PT; mean, 29.2 years), (2) quadruple-stranded hamstring tendon (HT; mean, 29.0 years), and (3) double bundle using HT (DB; mean, 28.8 years). Three hundred twenty-two patients completed 2-year follow-up. INTERVENTIONS: Anatomically positioned primary ACL reconstruction with PT, HT, and DB autografts. MAIN OUTCOME MEASURES: Proportions of complete traumatic reruptures, traumatic reinjuries (complete reruptures and partial tears), atraumatic graft failures, and contralateral ACL tears. Logistic regression assessed 5 a priori determined independent predictors: chronicity, graft type, age, sex, and Tegner level. RESULTS: More complete traumatic reruptures occurred in the HT and DB groups: PT = 3; HT = 7; DB = 7 (P = 0.37). Traumatic reinjuries statistically favored PT reconstructions: (PT = 3; HT = 12; DB = 11; P = 0.05). Atraumatic graft failures were not different: PT = 16; HT = 17; DB = 20 (P = 0.75). Younger age was a significant predictor of complete traumatic reruptures and traumatic reinjuries (P < 0.01). Higher activity level, males, and patients with HT, DB, and acute reconstructions had greater odds of reinjury. None of these factors reached statistical significance. Contralateral ACL tears were not different between groups, but trends suggested that younger females were more likely to have a contralateral ACL tear. CONCLUSIONS: More traumatic reinjuries occurred with HT and DB grafts. Younger age was a predictor of complete traumatic rerupture and traumatic reinjury, irrespective of graft type. LEVEL OF EVIDENCE: Level 1 (Therapeutic Studies). CLINICAL RELEVANCE: This article describes the complete traumatic graft rerupture, partial traumatic ACL tear, atraumatic graft failure, and contralateral ACL tear rates observed at 2 years postoperatively in a large double-blind RCT comparing PT, single-bundle hamstring, and double-bundle hamstring ACL reconstructions. The odds and predictive factors of traumatic rerupture and reinjury are also evaluated.

A Randomized Clinical Trial Comparing Patellar Tendon, Hamstring Tendon, and Double-Bundle ACL Reconstructions: Patient-Reported and Clinical Outcomes at a Minimal 2-Year Follow-up.

OBJECTIVE: To compare 3 anatomically positioned autografts for anterior cruciate ligament (ACL) reconstruction, by measuring patient-reported disease-specific quality of life at 2 years postoperatively. DESIGN: Double-blinded, randomized clinical trial with intraoperative computer-generated treatment allocation. Patients and an independent trained evaluator were blinded. SETTING: University-based orthopedic referral practice. PATIENTS: Three hundred thirty patients (14-50 years; 183 male patients) with isolated ACL deficiency were equally randomized to: (1) patellar tendon, PT: 28.7 years (SD = 9.7); (2) quadruple-stranded hamstring tendon, HT: 28.5 years (SD = 9.9); and (3) double bundle using HT, DB: 28.3 years (SD = 9.8); 322 patients completed 2-year follow-up. INTERVENTION: Anterior cruciate ligament reconstruction using PT, HT, or DB autografts. MAIN OUTCOME MEASURES: Measured at baseline, 1 and 2 years postoperatively-primary: anterior cruciate ligament quality-of-life scores; secondary: International Knee Documentation Committee (IKDC) scores, KT-1000 arthrometer, pivot shift, range of motion, Tegner activity, Cincinnati Occupational Scale, and single-leg hop. Proportions of correct graft type guesses by the patients and evaluator assessed blinding effectiveness. RESULTS: Baseline characteristics were not different. Anterior cruciate ligament quality-of-life scores increased over time for all groups (P = 0.001) but were not different at 2 years (P = 0.591): PT = 84.6 (SD = 16.6, 95% confidence interval [CI] = 81.4-87.8), HT = 82.5 (SD = 17.7, 95% CI = 79.2-85.9), and DB = 82.4 (SD = 17.5, 95% CI = 79.1-85.7). Two-year KT-1000 side-to-side differences (PT = 1.86 mm; HT = 2.97 mm; DB = 2.65 mm) were statistically significant between PT-HT (P = 0.002) and PT-DB (P = 0.044). The remaining secondary outcomes were not statistically different. Correct graft type guesses occurred 51% of the time for patients and 46% for the evaluator. CONCLUSIONS: Two-year disease-specific quality-of-life outcome was not different between the ACL reconstruction techniques. The PT reconstructions had significantly lower side-to-side differences on static stability measures. Patient and evaluator blinding was achieved. LEVEL OF EVIDENCE: Level 1 (Therapeutic Studies). CLINICAL RELEVANCE: This high-quality, large, double-blind randomized clinical trial (RCT) addresses the insufficient evidence in the literature comparing PT, single-bundle hamstring, and DB hamstring reconstructions for ACL rupture in adults. In addition to the clinical and functional results, this RCT uniquely reports on the disease-specific, patient-reported quality-of-life outcome at 2 years postoperatively.