Suture Anchor Biomechanics After Rotator Cuff Footprint Decortication.

PURPOSE: To identify the biomechanical consequences of violating the cortical shelf when preparing the greater tuberosity for suture anchor repair. METHODS: Demographic information and bone mineral density were obtained for 20 fresh-frozen human humeri (10 matched pairs). Suture anchors were placed at a predetermined location in decorticated and non-decorticated settings after randomization. Anchors were tested under cyclic loads followed by load-to-failure testing. The number of cycles, failure mode, stiffness, and final pullout strength were recorded. RESULTS: Nineteen specimens met the inclusion criteria for final testing. A significant difference in mean ultimate load to failure was seen between the non-decorticated specimens (244.04 ± 89.06 N/mm) and the decorticated humeri (62.84 ± 38.04 N/mm, P < .0001). Regression analysis showed positive correlations with female gender and decreased bone mineral density (P = .008 and P = .0005, respectively). CONCLUSIONS: Decortication of the rotator cuff footprint significantly decreases the pullout strength of the suture anchor. Gender and bone mineral density also play a significant role in bone-anchor biomechanics and should be considered during repair. CLINICAL RELEVANCE: Caution should be exercised when preparing the rotator cuff footprint before suture anchor placement because of the significant risk of early repair failure at the bone-anchor interface.

Hamstring autograft size can be predicted and is a potential risk factor for anterior cruciate ligament reconstruction failure.

PURPOSE: The purposes of this systematic review were (1) to determine whether there is a minimum hamstring autograft size for anterior cruciate ligament (ACL) reconstruction that significantly decreases the risk of failure and (2) to evaluate the methods to accurately and reliably predict the size of hamstring grafts. METHODS: We performed a systematic review of Level III and IV studies using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. All studies assessing failure of quadrupled-strand autograft hamstring ACL reconstruction as a function of graft diameter with at least 1 year of follow-up and those that assessed the use of imaging or anthropometric patient-specific factors to predict hamstring autograft size were included. RESULTS: We identified 4 clinical studies that directly compared graft size and failure rate. These correlated with a 6.8 times greater relative risk of failure if the graft diameter was equal to or less than 8 mm (P = .008). All 9 anthropometric-based prediction studies were able to significantly correlate at least 1 parameter with intraoperative graft size. Height was the most common correlation, with r = 0.45 (P < .00001). Five of 6 imaging-based prediction studies showed signification correlation, with r = 0.66 (P < .00001), between cross-sectional area and graft size. The most common method of imaging prediction was magnetic resonance imaging-derived cross-sectional area of both the semitendinosus and gracilis tendons. CONCLUSIONS: On the basis of the available evidence, ACL reconstruction with a quadrupled-strand hamstring autograft with a diameter equal to or larger than 8 mm decreases failure rates. In addition, grafts larger than 8 mm decrease failure rates in patients aged younger than 20 years, a group identified to be at increased risk of failure. Both patient height and magnetic resonance imaging-derived cross-sectional area of the hamstring tendons can be used preoperatively to reliably predict the hamstring autograft diameter. LEVEL OF EVIDENCE: Level IV, systematic review of Level III and IV studies.

Radiographic and clinical outcomes after instrumented reduction and transforaminal lumbar interbody fusion of mid and high-grade isthmic spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The objective of this study is to document and review the surgical technique and the clinical and radiographic outcomes after instrumented reduction and transforaminal lumbar interbody fusion of mid and high-grade adult isthmic spondylolisthesis. SUMMARY OF BACKGROUND DATA: Although high-grade slips make up a distinct minority of all patients afflicted with spondylolisthesis, approximately 2% in most series, the treatment of this small cohort of patients has been the topic of on going, and often heated debate. Recently, there has been a trend in the literature toward the combination of instrumented posterior spinal fusion (PSF) and interbody fusion with or without reduction. Although spine surgeons have used this procedure as a tool to treat patient's with spondylolisthesis of any cause, there is no report in the literature describing the results of neural element decompression, transforaminal interbody fusion (TLIF) reduction, and instrumented PSF of the listhetic vertebrae in the treatment of high and mid-grade isthmic spondylolisthesis. METHODS: From 1999 to 2003, 13 patients with mid and high-grade isthmic spondylolisthesis (Meyerding grades II, III, or IV) who failed conservative treatment were treated by posterior lumbar decompression, TLIF at the disk space of the level of the slip, instrumented PSF, and reduction of the listhetic vertebrae. Standing lumbar radiographs were taken preoperatively, at the time of the initial postoperative visit and at regular intervals thereafter. Several radiographic parameters were noted including degree of anterolisthesis, slip angle, sacral inclination, and disk height. Statistical comparisons were made with 2-tailed paired t tests. RESULTS: The average anterolisthesis, normalized to the superior endplate diameter, was 51.0%+/-16.6% preoperatively, 13.2%+/-11.8% immediately postoperative, and 17.0%+/-12.6% at final follow-up (Table 1). Of the 10 patients with sufficient radiographic follow-up, all but one had radiographic evidence of solid bony union at the time of final radiographic examination. Follow-up averaged 21.5 months and ranged from 11 to 48 months. CONCLUSIONS: This study represents a unified approach to the solitary diagnosis of mid and high-grade adult isthmic spondylolisthesis, adding further information to the growing body of literature for the TLIF procedure.

Biomechanical Comparison of a First- and a Second-Generation All-Soft Suture Glenoid Anchor.

BACKGROUND: All-soft tissue suture anchors provide advantages of decreased removal of bone and decreased glenoid volume occupied compared with traditional tap or screw-in suture anchors. Previous published data have led to biomechanical concerns with the use of first-generation all-soft suture anchors. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate the load to 2-mm displacement and ultimate load to failure of a second-generation all-soft suture anchor, compared with a first-generation anchor and a traditional PEEK (polyether ether ketone) anchor. The null hypothesis was that the newer second-generation anchor will demonstrate no difference in loads to 2-mm displacement after cycling compared with first-generation all-soft suture anchors. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty human cadaveric glenoids were utilized to create 97 total suture anchor sites, and 1 of 3 anchors were randomized and placed into each site: (1) first-generation all-soft suture anchor (Juggerknot; Biomet), (2) second-generation all-soft suture anchor (Suturefix; Smith & Nephew), and (3) a control PEEK anchor (Bioraptor; Smith & Nephew). After initial cyclic loading, load to 2 mm of displacement and ultimate load to failure were measured for each anchor. RESULTS: After cyclic loading, the load to 2-mm displacement was significantly less in first-generation anchors compared with controls (P < .01). However, the load to 2-mm displacement was significantly greater in second-generation anchors compared with controls (P < .01). There was no difference in ultimate load to failure between the first- and second-generation all-soft suture anchors (P > .05). CONCLUSION: The newer generation all-soft suture anchors with a theoretically more rigid construct and deployment configuration demonstrate biomechanical characteristics (specifically, with load to 2-mm displacement after cyclic loading) that are improved over first-generation all-soft suture anchors and similar to a traditional solid tap-in anchor. The configuration of these newer generation all-soft suture anchors appears to mitigate the biomechanical concerns of decreased load to failure with first-generation all-soft tissue suture anchors. CLINICAL RELEVANCE: The theoretical advantages of all-soft anchors may be particularly valuable in revision surgery or in cases where multiple anchors are being placed into a small anatomic area.

Return to play after treatment of shoulder labral tears in professional hockey players.

OBJECTIVES: Shoulder labral injuries in professional hockey players are often treated surgically to minimize missed ice time. Previous studies have shown that post-operative outcomes in these players are favorable, although they have not specifically focused on athletic performance and time to return to sport. Our objective was to report time to return to play and post-operative on-ice performance metrics after shoulder labral repair in professional ice hockey players. METHODS: We performed a retrospective review of the clinical records of all professional hockey players (NHL) who underwent arthroscopic shoulder labral repair by one surgeon between January 2004 and December 2008. Operative data included labral injury type, number of anchors used, concomitant pathology, and complications. Player information included position, shooting hand, games played before and after surgery, date of return to play (RTP), time on ice (TOI) and shots on goal before and after surgery. Paired sample t-test and independent sample t-tests or their non-parametric equivalents were used to compare pre-and post-operative player performance variables using the SPSS statistical package. RESULTS: Eleven NHL Players (13 shoulders) were included in the study. The average follow-up was 19.4 months (12.7-37 months, SD 7.4) and average age was 29 years (20-36, SD 5.1). Of the 13 shoulders, there were various types of labral tears including three Bankart tears, three superior (SLAP) tears, two posterior tears, three combined anterior/posterior tears, and two panlabral tears. All 11 players returned to play (RTP) after surgery at an average time of 4.3 months. There were no significant differences between time to RTP for players with dominant-sided injuries (4.2 months) and non-dominant injuries (4.6 months), p = 0.632. Five players had increased time-on-ice (TOI) and five players had decreased TOI after surgery, though this difference was not significant (p = 0.3804). On average, the shots on goal per game played (SOG/GP) decreased by 0.13 after surgery which was not significantly different (p = 0.149). There were no post-operative complications observed. CONCLUSION: Professional ice hockey players can safely return to full competition at an average of 4.3 months after arthroscopic shoulder labral repair without significant decline in player performance.

Results of ACL reconstruction with tibial Retroscrew fixation: Comparison of clinical outcomes and tibial tunnel widening.

UNLABELLED: ACL reconstruction with the RetroScrew™ shows superior clinical outcomes compared to historical Achilles allograft studies with antegrade screws. Addition of antegrade screw augmentation to retrograde fixation causes an increase in tibial tunnel widening. INTRODUCTION: In traditional antegrade screw fixation of Anterior cruciate ligament (ACL) soft tissue allografts, the screw is secured in the opposite direction of graft tension, potentially altering the appropriate tension on the graft. The RetroScrew (Arthrex) is a bioabsorbable screw placed in a retrograde fashion, potentially improving the tension of the graft by placing the screw in a proximal-to-distal direction. In addition, the RetroScrew theoretically decreases tibial tunnel widening by closing the aperture of the tibial tunnel, which prevents ingress of synovial fluid. Early tunnel expansion has been implicated due to excessive transverse and longitudinal graft motion. The clinical effects of tunnel expansion have yet to be fully understood. The purpose of this study is to assess the clinical results and tunnel width after ACL soft tissue fixation in the tibia with the RetroScrew. METHODS: Fifty-nine patients who underwent ACL reconstruction performed by two surgeons using the RetroScrew device returned for postoperative evaluation at an average of 25 months following surgery with a minimum follow-up of 12 months. Clinical evaluation, SF-36, IKDC and KT-1000 scores were recorded, and knee radiographs were used to measure tibial tunnel widening. Thirty-five patients had backup antegrade screw fixation in conjunction with the RetroScrew, and 24 patients had RetroScrew fixation alone. The results were compared to two previously reported studies on ACL reconstruction with Achilles tendon allograft that used antegrade screws. RESULTS: The average IKDC score was 87 (range: 44-100), with mean KT-1000 side-to-side difference of 1.2 mm (range: 0-5 mm). Tibial tunnel widening was 4.93 mm (SD 3.32) on AP radiographs and 4.40 mm (SD 2.72) on lateral radiographs greater than the native tunnel drilling. Patients with additional backup fixation had significantly more tunnel widening than patients without backup fixation (P < 0.05). There was one failure based on KT-1000 measurements. When compared to previous studies using ACL allografts, RetroScrew patients had statistically superior Lachman exams, KT-1000 side-to-side differences and decreased tibial tunnel widening (P < 0.05) when antegrade fixation was excluded. CONCLUSION: Patients who underwent Achilles allograft ACL reconstruction with the RetroScrew had improved clinical results compared to historical controls using antegrade fixation. Tibial tunnel widening was increased when using additional antegrade screw fixation, suggesting that the amount of bioabsorbable material within the tibial tunnel was related to the degree of tunnel widening.