Quadriceps Strength and Knee Function After Anterior Cruciate Ligament Reconstruction with Quadriceps Tendon Bone Autograft: A Preliminary Report.

Introduction: The purpose of this study was to evaluate quadriceps strength and knee function after anterior cruciate ligament (ACL) reconstruction using a quadriceps tendon bone (QTB) autograft. Methods: Preliminary data were extracted from an ongoing prospective cohort study in which the operative extremity was compared to non-operative extremity. Patients from 14 to 40 years of age who had an ACL reconstruction with QTB autograft volunteered to have knee assessment including quadriceps isokinetic strength measures and functional knee testing at 6 and 12 months post-operatively. Paired t-tests were conducted to compare post-operative strength and function scores on participants who had minimum one-year post-surgical follow-up. Results: Patients had a significant recovery of quadriceps strength as determined by isokinetic testing and single leg hop test. For 31 participants, quadriceps strength of the operative leg measured at 60 deg/sec was 63% of the non-operative leg at six months, increasing to 79% at one year (p < 0.001); when measured at 180 deg/sec, these values were 68% at six months, increasing to 82% at one year (p < 0.001). For 30 participants, single leg hop functional scores of the operative leg were 80% of the non-operative leg at six months, increasing to 91% at one year (p < 0.001). Conclusions: After QTB autograft for ACL reconstruction, there were significant gains in quadriceps strength and knee function from six months to one year post-operative. These findings indicated the QTB is an acceptable ACL reconstruction option.

Supraspinatus Fatty Infiltration Correlation with Handgrip Strength, Shoulder Strength, and Validated Patient-Reported Outcome Measures in Patients with Rotator Cuff Tears.

Introduction: The purpose of this study was to investigate the relationships between supraspinatus atrophy on magnetic resonance imaging (MRI) and other objective parameters in patients with rotator cuff tears. It was hypothesized that high-grade supraspinatus fatty infiltration would be correlated negatively with handgrip strength, shoulder strength, and patient-reported outcome measures (PROMs). Methods: Patients with MRI-proven rotator cuff tears treated by a single sports medicine fellowship-trained orthopaedist at a single institution underwent comprehensive preoperative evaluation including bilateral handgrip and shoulder strength measurements with dynamometers and multiple online questionnaires from the Surgical Outcomes SystemTM (Arthrex, Naples, FL). Available shoulder MRIs were reviewed to grade supraspinatus fatty infiltration severity according to the 5-tier Goutallier system and an alternate 3-tier classification scheme. Difference analysis and Spearman (rho) rank order correlation were applied to the collected data to define the relationships between supraspinatus fatty infiltration and key variables including handgrip strength, shoulder strength, and scores derived from the shoulder PROMs. Results: Ninety of the 121 patients enrolled in the study had shoulder MRIs available for review. There was no correlation found between supraspinatus fatty infiltration and handgrip strength, shoulder abduction strength, or any of the seven common shoulder PROM scores evaluated. There was statistically significant, albeit weak, correlation between MRI-derived fatty infiltration and shoulder external rotation strength. Conclusions: Contrary to the hypothesis, high-grade supraspinatus fatty infiltration is largely unrelated to and should not be considered predictive of handgrip strength, shoulder strength, or common shoulder PROM scores.

The Effect of Different Combinations of Three Stacked Half-Hitches and Suture Materials on an Arthroscopic Knot in a Dry or Wet Environment.

Purpose: Evidence is lacking on the effect of different combinations of three stacked half-hitches and suture materials on the loop/ knot security of an arthroscopic knot under cyclic loading conditions. The specific aim of this study was to identify variables, such as stacked half-hitch configurations, suture materials, and testing environments, that affect knot strength and loop security under cyclic loading conditions. Methods: Two suture materials (Orthocord and ForceFiber) were used to tie five differently stacked reversing half-hitches on alternating posts (RHAP) in an arthroscopic knot condition. All knots were evaluated in both dry and wet cyclic loading tests. Results: Knots tied with three identical half-hitches stacked on the same post (Conf #1) resulted in 100% knot slippage regardless of suture material in dry environment. In the wet environment this knot configuration performed slightly better (ForceFiber: 20% survived; Orthocord: 40% survived). With knots tied with one of the half-hitches in the RHAPs reversed, a significant improvement occurred in knot holding compared to Conf #1 (p<0.05). Knots tied with the last half-hitches in the RHAPs reversed using ForceFiber were 100% secure in both test environments; whereas those tied with Orthocord had 70% and 80% security rates in the respective environments. Knots tied with two half-hitches of the RHAPs reversed demonstrated the best overall performance. Conclusion: Significant effects for both stacked half-hitch configurations and suture materials on the knot loop and knot security were observed. Caution should be used when tying the 3 RHAPs in a knot using standard arthroscopic techniques. This study may provide a solution that might improve the maximum failure loads observed between orthopaedic surgeons, and achieve better clinical outcomes. Clinical Relevance: The findings of this study indicate the importance of three reversing half-hitches on alternating posts in performing arthroscopic knot tying, and provide evidence regarding discrepancies of maximum clinical failure loads observed between orthopaedic surgeons leading to better surgical outcomes.

Evaluating Different Clinical Diagnosis of Anterior Cruciate Ligament Ruptures In Providers with Different Training Backgrounds.

INTRODUCTION: Previous studies have shown that provider training and the tests performed play a role in the accuracy of diagnosis of anterior cruciate ligament (ACL) injuries. The specific aim of the current study is to determine the examiner proficiency and accuracy in performing the different proactive tests of ACL rupture before and after the induction of anesthesia prior to a definitive surgical procedure. MATERIALS AND METHODS: A case series was performed from January of 2015 through July of 2015. Two examiners were included (an experienced orthopaedic sports surgeon with more than 16 years in practice and an experienced orthopaedic physician assistant with 6 years of clinical experience in orthopaedic sports medicine). Three different physical examination tests were used before and after the induction of anesthesia to the patient: 1) Lachman test, 2) pivot shift test, and 3) Lelli test. Relevant patient demographic information such as BMI, thigh girth, and calf girth were recorded. Diagnosis of ACL rupture had been established pre-operatively. RESULTS: Thirty three patients met the inclusion criteria (males: 21 (64%), female: 12 (36%)). High percent of false negative was found with pivot shift test for both before and after anesthesia when compared to the other two tests. The Lelli test seemed to be most favorable to both the surgeon and the physician assistant with at least 67% favorable, while the pivot shift was least often felt to be the most useful test. No relationship was found for either patients' thigh or patients' calf girths with the physical examination test results for both examiners for any of the three tests (p = 0.110). CONCLUSION: The diagnostic accuracy and limitations of the various tests for ACL injury need to be understood. Clinically, it is recommended performing at least two different examinations, as each test has its own specific limitations. Level of Evidence: III- Prospective Cohort Study without blinding.

Strength of Resistance to "Flip" the Tightened Half-Hitches of an Arthroscopic Knot.

PURPOSE: The purpose of this study was to biomechanically determine the minimum strength required to "flip" a seated and tightened half-hitch in a knot of different braided polyblend sutures. METHODS: ForceFiber, FiberWire, Orthocord, and Ultrabraid were evaluated. All knot tying processes began by advancing an initial base knot down to a standardized rod. All half-hitches were tied using a single-hole knot pusher in a dry environment, and were tightened with 45N by using past-pointing maneuver. A tension was then deliberately applied to the wrapping suture limb until a "flip" occurred, and the amount of tension was measured by the load cell. Three trials for each half-hitch and 3 half-hitches for each arthroscopic knot with 12 knots of each material were tied. All respective tension loads were collected through the digital video recordings (knot closeup view and load cell reading). RESULTS: Orthocord was the easiest to "flip" a seated and tightened half-hitch (average: 10±3N), whereas Ultrabraid was hardest to "flip" (average: 23±7N). ForceFiber and FiberWire were about 49% and 15% more resistance to "flip" when compared to Orthocord. After each trial of flipping the half-hitch back and re-tightened, there was a significant reduction in strength required to "flip" the tightened half-hitch. CONCLUSION: 1) The unintentional minimum tensile strength greater than 10N applied to the wrapping suture limb on the seated and tightened half-hitch could potentially "flip" the half-hitch in a knot during arthroscopic procedures, and 2) different braided suture material has an affect on the tensile strength to "flip" a seated and tightened half-hitch in an arthroscopic knot. CLINICAL RELEVANCE: The findings of this study indicated that even a seated and tightened half-hitch in an arthroscopic knot could easily be "flipped" if an unintentional tension was applied to the wrapping suture limb, and thereby reduced the knot security strength. In addition different suture materials could have an effect on the strength needed to "flip" the tightened half-hitch.

Validation of Different Combination of Three Reversing Half-Hitches Alternating Posts (RHAPs) Effects on Arthroscopic Knot Integrity.

INTRODUCTION: With arthroscopic techniques being used, the importance of knot tying has been examined. Previous literature has examined the use of reversing half-hitches on alternating posts (RHAPs) on knot security. Separately, there has been research regarding different suture materials commonly used in the operating room. The specific aim of this study was to validate the effect of different stacked half-hitch configuration and different braided suture materials on arthroscopic knot integrity. METHODS: Three different suture materials tied with five different RHAPs in arthroscopic knots were compared. A single load-to-failure test was performed and the mean ultimate clinical failure load was obtained. RESULTS: Significant knot holding strength improvement was found when one half-hitch was reversed as compared to baseline knot. When two of the half-hitches were reversed, there was a greater improvement with all knots having a mean ultimate clinical failure load greater than 150 newtons (N). Comparison of the suture materials demonstrated a higher mean ultimate clinical failure load when Force Fiber® was used and at least one half-hitch was reversed. Knots tied with either Force Fiber® or Orthocord® showed 0% chance of knot slippage while knots tied with FiberWire® or braided fishing line had about 10 and 30% knot slippage chances, respectively. CONCLUSIONS: A significant effect was observed in regards to both stacked half-hitch configuration and suture materials used on knot loop and knot security. Caution should be used with tying three RHAPs in arthroscopic surgery, particularly with a standard knot pusher and arthroscopic cannulas. The findings of this study indicated the importance of three RHAPs in performing arthroscopic knot tying and provided evidence regarding discrepancies of maximum clinical failure loads observed between orthopaedic surgeons, thereby leading to better surgical outcomes in the future.

Reverse Flipping Technique: An Alternate Approach to Tie Reversing Half-Hitches on Alternating Posts.

Arthroscopic knot tying requires practice and attention to detail, especially tying the 3 reversing half-hitches on alternating posts (RHAPs) in a knot. Mistakes can occur that result in an unintentional tension (>10 N) applied to the wrapping suture limb, and by placing tension in the wrong limb, the previously "flipped" half-hitch is converted from a series of RHAPs into a series of identical half-hitches on the same post, thereby producing insecure knots or suture loops. This was hypothesized to be a source of knot failure by knot slippage. This error can be avoided by using a technique we describe as "reverse flipping," which purposely "flips" the half-hitch down at the main knot while tying the 3 RHAPs in a knot, and then the half-hitch is retightened using either a past-pointing or over-pointing technique. This way the surgeon can be absolutely sure that the half-hitch is tightened in the direction that it was intended to be placed, and can also prevent the unintentional tension applied to the wrapping suture limb that causes the half-hitch to "flip." However, caution should be used when tensioning the half-hitches; overtensioning (>40 N) during past-pointing or over-pointing could also potentially "flip" the previous half-hitch that has already been tightened and cause potential knot failure.

Validation of Improvement of Basic Competency in Arthroscopic Knot Tying Using a Bench Top Simulator in Orthopaedic Residency Education.

PURPOSE: To validate basic competency in arthroscopic knot tying using a unique simulator device to compare the level of training needed for learning and tying the arthroscopic knot by evaluating the tensile properties of the arthroscopic knots. METHODS: Three groups of surgeons of various experience levels (postgraduate year [PGY] 1, PGY 3, and experienced surgeons) tied 2 different arthroscopic knots (Tennessee Slider, considered easier, and Weston, considered more difficult) over a 10-week period. Each group went through 3 separate stages of knot tying: stage 1, tying 8 knots without cannula or knot pusher; stage 2, tying 12 knots with knot pusher; and stage 3, tying 20 knots with knot pusher through a cannula that simulates knot tying during surgery. A single load-to-failure test was performed and ultimate clinical failure loads were recorded. Time needed to tie each knot was also recorded. RESULTS: At stages 1 and 2, the PGY 1 group had a significantly weak knot tensile strength (Tennessee Slider stage 1: 60 v 129 N, P = .001; Tennessee Slider stage 2: 69 v 132 N, P = .0029; Weston stage 1: 73 v 184 N, P = .0000; Weston stage 2: 125 v 173 N, P = .0045) and were slower (Weston: 56 v 30 seconds, P = .0010) than the experienced surgeon group for both knots. At stage 3, only the initial 2 weeks of Tennessee Slider showed a significant difference between groups 1 and 3 (week 6: 87 v 118 N, P = .0492; week 7: 89 v 126, P = .01485). Even though the Tennessee Slider knot is one of the easier arthroscopic knots to learn to tie, the results showed a slow trend of improvement in this knot-tying skill for group 1 after each stage. CONCLUSIONS: The data validated an important learning effect in all trainees in arthroscopic knot tying over a 10-week period and showed that inexperienced trainees will be able to improve their knot-tying skill with training in 3 stages with a simulator environment. CLINICAL RELEVANCE: The findings of this study indicated the importance of hands-on experience in performing arthroscopic knot tying, as determined by both knot performance and ultimate suture loop strength. In addition, each orthopaedic resident learned and developed his or her arthroscopic knot-tying skills and provided a foundation for his or her future practice in orthopaedic medicine.

In vitro and in situ characterization of arthroscopic loop security and knot security of braided polyblend sutures: a biomechanical study.

We conducted a study to evaluate biomechanical performance during destructive testing of several different suture materials in various arthroscopic knot configurations under both in vitro and in situ conditions. Surgeons of different levels of experience tied the knots. Three different arthroscopic knots (static surgeon's, Weston, Tennessee slider) with 3 reverse half-hitches on alternating posts were tested using Fiberwire, ForceFiber, Orthocord, and Ultrabraid suture materials under both in vitro and in situ (blood plasma at 37°C) conditions. Three surgeons of different experience levels tied the knots on a post 30 mm in circumference. A single load-to-failure test was performed. There were no significant in vitro-in situ differences for Ultrabraid in the different knot configurations or with the different experience levels. Surgeon B (intermediate experience) showed no significant differences between test conditions for any knot configuration or suture material. With Tennessee slider knots, surgeon C (least experience) showed significantly lower clinical failure load under both test conditions and had a higher percentage of complete knot slippage. Surgeon B had no knot slippage with use of Fiberwire. Both the aqueous environment and the surgeon's familiarity with certain knots have an effect on knot security.

Knot security, loop security, and elongation of braided polyblend sutures used for arthroscopic knots.

In the study described here, we evaluated load to failure and cyclic loading elongation of different braided polyblend sutures under different sliding knot configurations. Four braided polyblend sutures (FiberWire, Herculine, Orthocord, Ultrabraid) were tied with 5 sliding arthroscopic knots (Static surgeon, Weston, Roeder, Nicky, Tennessee slider) with a series of 3 reversing half-hitches on alternating posts (RHAPs). Each knot was tied around a 30-mm circumference post to ensure a consistent loop circumference. Loop security was measured as load to failure (load at 3-mm cross-head displacement or suture breakage) and loop elongation at a frequency of 1 Hz from 6 N to 30 N for 1000 cycles. Twenty knots were tied for each possible combination of knots and sutures, 10 for load to failure and 10 for cyclic loading test. For any given knot type, tying with Ultrabraid suture material resulted in maximum performance in the maximum load-to-failure test. Conversely, tying with Orthocord resulted in a significantly lower maximum load to failure, with the exception of the Surgeon knot. The Weston knot with 3 RHAPs using Ultrabraid provided the highest load to failure(mean, 346 N; SD, 24 N). All knots elongated less than 0.45 mm at the 1000th cycle and experienced higher suture slippage at initial cyclic loading (50th cycles). At higher cycles, FiberWire and Orthocord demonstrated less than half of the suture slippage of Herculine and Ultrabraid (5x10(-5) vs 11x10(-5) mm/cycle). Different braided polyblend sutures provide different knot and loop security for a given type of sliding knot. All knots in this study appear to be durable with respect to resistance to loosening under cyclic loading conditions. The Weston knot with 3 RHAPs using Ultrabraid provided the best loop and knot security. Our study results help further our understanding of the biomechanics of knot and loop security differences for different braided polyblend sutures.

Isolated posterior cruciate ligament rupture presenting as a locked knee.

Mechanical symptoms in the knee, especially locking, are most commonly associated with meniscal pathology. We present an atypical case of locking of the knee secondary to an isolated posterior cruciate ligament tear.