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David N M Caborn

Publications and source records attributed to David N M Caborn.

At least 19 recordsLinked to original sources
PubMed2006

Pullout strength of meniscal repair after cyclic loading: comparison of vertical, horizontal, and oblique suture techniques.

This in vitro biomechanical study with cyclic loading compared the pullout strength of vertical, horizontal, and oblique sutures used for meniscal lesion repair. Following repair of vertical longitudinal lesions created in bovine medial menisci, three groups of seven specimens (vertical, horizontal, and oblique sutures) underwent cyclic loading in a randomized test order (5 mm/min, cycling between 5 and 50 N at 1 Hz for 100 cycles) prior to load to failure testing (5 mm/min). Displacement did not differ between groups during cyclic or load to failure testing. Construct stiffness during cyclic testing was superior for the oblique suture (6.9 +/- 1.5 N/mm, P = 0.007) and the vertical suture (6.4 +/- 7 N/mm, P = 0.03) groups compared to the horizontal suture group (4.4 +/- 0.52 N/mm). The oblique suture (171.9 +/- 25.9 N, P < 0.0001) and the vertical suture (145.9 +/- 32.3 N, P = 0.001) groups displayed superior load at failure compared to the horizontal suture group (88.8 +/- 8.2 N). Construct stiffness during load to failure testing did not differ between groups. Suture rupture was the failure mode for all specimens of the oblique suture group. Suture rupture was the failure mode for 57% (4/7) of the vertical suture group with the remaining specimens (3/7, 43%) failing from intact suture pullout through meniscal tissue. All horizontal suture group specimens failed by intact suture pulling through meniscal tissue. With comparable stiffness during cyclic testing, comparable load at failure as vertical sutures, and less evidence of intact suture pullout through the meniscus, an oblique suture technique may combine the beneficial characteristics of vertical (superior biomechanical strength) and horizontal (ease of application, longer sutures with a tendency to cover a larger meniscal tissue area) suture-repair techniques.

Animals↗
PubMed2006

A biomechanical comparison of the FasT-Fix meniscal repair suture system and the RapidLoc device in cadaver meniscus.

PURPOSE: This biomechanical study compared the fixation characteristics of horizontally or vertically implanted FasT-Fix devices (Smith & Nephew, Endoscopy Division, Andover, MA) consisting of two 5-mm PLLA suture T-bar anchors with a pretied self-sliding knot (No. 0 nonabsorbable, USP, braided polyester suture material) and the RapidLoc device (Mitek Surgical Products, Westwood, MA) consisting of a PLLA T-bar anchor or "backstop," a connecting suture (No. 2 nonbiodegradable Ethibond; Ethicon, Somerville, NJ), and a PLLA grommet, for repairing posterior third lesions in human menisci. TYPE OF STUDY: Controlled laboratory biomechanical study. METHODS: After repair of a vertical longitudinal meniscus lesion with either vertically or horizontally implanted FasT-Fix devices or RapidLoc devices, 3 groups of 6 specimens underwent cyclic loading (5 mm/minute, cycling between 5 and 50 N at 1 Hz for 500 cycles) before load to failure testing on a servo hydraulic device. One-way analysis of variance and Tukey HSD post hoc tests were used to evaluate group differences (P < .05). RESULTS: The vertical FasT-Fix device group (3.2 +/- 0.49 mm) had less displacement after cyclic testing than either the horizontal FasT-Fix (4.4 +/- 0.73 mm, P = .003) or the RapidLoc (4.6 +/- 0.22 mm, P = .002) device groups. The vertical FasT-Fix device group had greater stiffness during cyclic testing (14.4 +/- 2.1 N/mm) than the horizontal FasT-Fix (10.4 +/- 1.6 N/mm, P = .0001) or the RapidLoc (9.7 +/- 0.44 N/mm, P = .0001) device groups. During load to failure testing, the vertical FasT-Fix group (125.3 +/- 39 N) had 28% greater strength than the horizontal FasT-Fix device group (89.7 +/- 14 N, P = .02) and 30% greater strength than the RapidLoc device group (87.1 +/- 13 N, P = .028), whereas displacement and stiffness did not show statistically significant group differences. CONCLUSIONS: The vertical FasT-Fix group had superior biomechanical characteristics for meniscal fixation during cyclic and load to failure testing compared with horizontal FasT-Fix or RapidLoc devices. CLINICAL RELEVANCE: Although the RapidLoc devices provided fixation characteristics comparable to horizontally implanted FasT-Fix devices, vertically implanted FasT-Fix devices may provide superior all-inside fixation.

Absorbable Implants↗
PubMed2006

Effect of lesion location on fixation strength of the meniscal viper repair system: an in vitro study using porcine menisci.

PURPOSE: The Meniscal Viper Repair System (Arthrex, Naples, FL) is a novel suture-based all-inside meniscal repair system. This study was performed to test whether the Meniscal Viper Repair System would provide superior fixation characteristics for vertical longitudinal meniscal lesions located closer to the periphery compared with those located further away from the periphery. METHODS: Vertical longitudinal lesions were created either 1 to 2 mm or 3 to 4 mm away from the periphery of porcine menisci. After repair with the Meniscal Viper Repair System, fixation characteristics were studied during cyclic (500 cycles, 5 to 50 N) and load to failure testing (5 mm/min) in a servo hydraulic device. RESULTS: Meniscal lesion repair location did not show significant differences in displacement or stiffness during cyclic testing. During load to failure testing, meniscal lesion repairs located 1 to 2 mm from the periphery showed superior load at failure (188.8 +/- 45.4 N) compared with repairs located 3 to 4 mm from the periphery (114.4 +/- 35.0 N) (P = .01). Stiffness and displacement during load to failure testing did not show statistically significant differences. CONCLUSIONS: The Meniscal Viper Repair System provides stronger meniscal repair strength when lesions are located within 1 to 2 mm of the periphery. CLINICAL RELEVANCE: The Meniscal Viper Repair System is better suited for repair of peripheral meniscal lesions located within 1 to 2 mm of the periphery. For lesions located in zone 2 (within the central 50%), careful assessment of their distance from the periphery is recommended. For lesions located more than 3 to 4 mm away from the periphery, alternative repair systems or augmentation with other devices may be prudent.

Animals↗
PubMed2006

Self-reported patient outcomes at a minimum of 5 years after allograft anterior cruciate ligament reconstruction with or without medial meniscus transplantation: an age-, sex-, and activity level-matched comparison in patients aged approximately 50 years.

PURPOSE: Patient outcomes at a minimum of 5 years after medial meniscus transplantation and primary anterior cruciate ligament (ACL) reconstruction via allograft tissues were compared with those of age-, sex-, and activity level-matched patients who underwent meniscal repair or partial meniscectomy and primary ACL reconstruction via allograft tissues. METHODS: Eight patients (mean age, 51 +/- 5 years; three women and five men) at 5.5 +/- 0.5 years after medial meniscus transplantation and ACL reconstruction (group 1) and eight matched patients (mean age, 50 +/- 5 years; three women and five men) at 5.1 +/- 0.5 years after meniscal repair or partial meniscectomy and ACL reconstruction (group 2) completed the meniscus allograft clinical registry questionnaire, which combined the modified Lysholm knee scoring scale, the 1999 International Knee Documentation Committee subjective knee evaluation, and the knee pain level score on a 10-cm visual analog scale. RESULTS: Both groups displayed similar improvements in the modified Lysholm knee scoring scale components of pain, knee stability, squatting, stair climbing, and limping, as well as overall score (P < .05). Only group 2 displayed significant reductions in swelling. The groups displayed similar improvements in the 1999 International Knee Documentation Committee subjective knee evaluation components of sitting, rising from a chair, running, jumping, and stopping quickly, as well as overall score (P < .05). They also displayed significant improvements in the visual analog scale knee pain level score; however, group 1, which displayed greater preoperative pain levels, had considerably larger reductions. Most group 1 patients (7/8 [87.5%]) and all group 2 patients (8/8 [100%]) considered their surgery to be a success and would undergo the same procedure again if necessary. CONCLUSIONS: Although group 1 had greater preoperative knee pain levels, their pain levels at 5 years postoperatively were comparable to those in group 2. With the exception of swelling, comparable improvements were observed between groups for all other variables. LEVEL OF EVIDENCE: Level III, retrospective, case-control study.

Activities of Daily Living↗
PubMed2006

Self-reported outcomes after anterior cruciate ligament reconstruction: an internal health locus of control score comparison.

PURPOSE: The purpose of this study was to evaluate the influence of high or low internal health locus of control (HLOC) scores on knee function and sports activity self-reports. METHODS: The Multidimensional HLOC Scale, the Knee Outcome Survey (KOS) Activities of Daily Living Scale (ADLS) and Sports Activity Scale (SAS), and the 2000 International Knee Documentation Committee (IKDC) Subjective Knee Evaluation and Current Health Assessment surveys were mailed to 335 subjects at a minimum of 2 years after anterior cruciate ligament reconstruction. RESULTS: Of the subjects, 198 returned completed surveys at 5.1 +/- 2.9 years after surgery. Compared with the group with low internal HLOC scores, the group with high internal HLOC scores had better KOS-ADLS scores (89.6 +/- 13.7 v 77.4 +/- 23.9, P < .0001), KOS-SAS scores (85.2 +/- 18 v 70 +/- 29, P < .0001), global ADLS ratings (90.7 +/- 12.8 v 77.4 +/- 23.9, P < .0001), global SAS ratings (81.8 +/- 20.6 v 70 +/- 29.4, P < .0001), 2000 IKDC Subjective Knee Evaluation scores (80.9 +/- 17.7 v 68.3 +/- 25.2, P < .0001), and 2000 IKDC Current Health Assessment scores for physical function (90.2 +/- 14 v 80.5 +/- 24.6, P = .001), social function (92.6 +/- 14.8 v 85.8 +/- 21.1, P = .014), bodily pain (80.7 +/- 17.7 v 68.7 +/- 24.6, P < .001), mental health (77.9 +/- 14.2 v 70.6 +/- 19.2, P = .005), and vitality (65.1 +/- 19 v 58.8 +/- 21, P = .04). Current knee function scores (8.7 +/- 1.8 v 7.1 +/- 2.9, P < .0001) and KOS-SAS sports activity level scores (chi(2) = 11.2, P = .01) were also higher in the group with high internal HLOC scores compared with the group with low scores. CONCLUSIONS: Patients with high internal HLOC scores were more satisfied with knee function. LEVEL OF EVIDENCE: Level IV, prognostic case series.

Activities of Daily Living↗
PubMed2006

Self-reported patient outcomes after ACL reconstruction with allograft tissue.

PURPOSE: Self-reported outcomes after primary ACL reconstruction using allograft tissues were compared at > or = 5 yr (group 1) and at 2-4 yr (group 2) after surgery. METHODS: The IKDC Subjective Knee Evaluation and Current Health Assessment and the Knee Outcome Survey Activities of Daily Living Scale (KOS-ADLS) and the Sports Activity Scale (KOS-SAS) were mailed to 335 consecutive former patients at > or = 2 yr after surgery. RESULTS: Surveys were completed and returned by 64.6% of former patients. Time after surgery for group 1 (N = 90) and group 2 (N = 116) was 7.8 +/- 2.7 and 2.8 +/- 0.8 yr, respectively. Groups did not differ for IKDC Subjective Knee Evaluation or KOS-ADLS scores, although group 1 displayed a lower mean KOS-SAS score. Pooled IKDC Subjective Knee Evaluation scores were 42.7% normal (A), 22.8% nearly normal (B), 24.8% abnormal (C), or 9.7% severely abnormal (D). Pooled standardized IKDC Subjective Knee Evaluation z scores were -0.80 +/- 1.4 standard deviations below the reported population mean for unimpaired individuals with 33.5% scoring at or above the normative population mean, 28.2% scoring < 1 standard deviation below the normative population mean, 18.8% scoring between 1 and 2 standard deviations below the normative population mean, and 19% scoring > or = 2 standard deviations below the normative population mean. Pooled KOS-ADLS scores were 62.1% (> or = 90%), 18% (89-80%), 10.2% (79-70%), and 9.7% (< 70%). Pooled KOS-SAS scores were 49.5% (102/206, > or = 90%), 25.7% (53/206, 89-80%), 9.7% (20/206, 79-70%), and 15.1% (31/206, < 70%). Groups displayed comparable knee function before injury and at the time of the survey. Pooled knee-function scores decreased from 9.5 +/- 1.6 before injury to 8 +/- 2.5 current function (84% return). Both groups displayed decreases in current sports activity level from strenuous to moderate and frequency from 4-7 to 1-3 times per week. CONCLUSIONS: Self-reported outcomes did not differ between groups for the IKDC Subjective Knee Evaluation or for the KOS-ADLS score, although group 1 displayed decreased mean KOS-SAS scores, suggesting decreased perceived sporting activity knee function at > or = 5 yr after surgery. Decreased sports activity level and frequency are comparable with self-reported outcome studies after primary ACL reconstruction using autograft tissues.

Activities of Daily Living↗
PubMed2005

Comparison of volumetric bone mineral density in the tibial region of interest for ACL reconstruction.

Adequate tibial bone mineral density (BMD) is essential to soft tissue graft fixation during anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to compare volumetric bone plug density measurements at the tibial region of interest for ACL reconstruction using a standardized immersion technique and Archimedes' principle. Cancellous bone cores were harvested from the proximal, middle, and distal metaphyseal regions of the lateral tibia and from the standard tibial tunnel location used for ACL reconstruction of 18 cadaveric specimens. Proximal tibial cores displayed 32.6% greater BMD than middle tibial cores and 31.8% greater BMD than distal tibial cores, but did not differ from the BMD of the tibial tunnel cores. Correlational analysis confirmed that the cancellous BMD in the tibial tunnel related to the cancellous BMD of the proximal and distal lateral tibial metaphysis. In conjunction with its adjacent cortical bone, the cancellous BMD of the region used for standard tibial tunnel placement provides an effective foundation for ACL graft fixation. In tibia with poor BMD, bicortical fixation that incorporates cortical bone from the distal tibial tunnel region is recommended.

Aged↗
PubMed2005

Biomechanical evaluation of meniscal repair systems: a comparison of the Meniscal Viper Repair System, the vertical mattress FasT-Fix Device, and vertical mattress ethibond sutures.

BACKGROUND: The biomechanical characteristics of the Meniscal Viper Repair System have not been previously studied. HYPOTHESIS: Comparable meniscal lesion fixation standards will exist among the Meniscal Viper Repair System, the vertical FasT-Fix device, and vertical mattress sutures. STUDY DESIGN: Controlled laboratory study. METHODS: Porcine menisci (3 groups of 7 menisci each) were repaired using different devices. A servohydraulic device cycled each construct between 5 N and 50 N for 500 cycles before load to failure (5 mm/min). Group differences were evaluated with 1-way analysis of variance and Tukey post hoc tests. RESULTS: During cyclic testing, the vertical mattress suture group (2.3 +/- 0.2 mm) showed less mean displacement than did the vertical FasT-Fix or the Viper system groups (3.9 +/- 0.7 mm and 3.9 +/- 0.5 mm, respectively); the vertical mattress suture group (21.8 +/- 2 N/mm) also displayed superior mean stiffness to the vertical FasT-Fix or the Viper system groups (13.2 +/- 2 N/mm and 13.1 +/- 1.8 N/mm, respectively). During load-to-failure testing, the vertical FasT-Fix group (145.9 +/- 9 N) withstood greater mean loads than did the Viper system group (111.2 +/- 30 N), but it did not differ significantly from loads withstood by the vertical mattress suture group (133.4 +/- 10 N). The Viper system and vertical FasT-Fix groups (14.6 +/- 2 N/mm and 12.1 +/- 1 N/mm, respectively) displayed superior mean stiffness to the vertical mattress suture group (9.8 +/- 0.5 N/mm) during load-to-failure testing. CLINICAL RELEVANCE: Standard vertical mattress sutures provided superior fixation during cyclic loading compared with the 2 all-inside methods of suture fixation, suggesting a potential for better meniscal lesion healing with vertical mattress sutures when confronted with the stresses associated with early, progressive rehabilitation activities. Stronger sutures and less meniscal segment purchase in tears located 3 to 4 mm from the periphery may contribute to the failure of the Viper repair system.

Absorbable Implants↗
PubMed2005

Biomechanical comparison of the bioabsorbable RetroScrew system, BioScrew XtraLok with stress equalization tensioner, and 35-mm Delta Screws for tibialis anterior graft-tibial tunnel fixation in porcine tibiae.

BACKGROUND: Achieving effective soft tissue graft-tibial tunnel fixation remains problematic. HYPOTHESIS: No differences would exist for tibialis anterior graft-tibial tunnel fixation when comparing the RetroScrew System (20-mm retrograde screw, 17-mm antegrade screw), the 35-mm tapered Delta Screw (manual tensioning), and the 35-mm BioScrew XtraLok (applied using an instrumented tensioner). STUDY DESIGN: Controlled laboratory study. METHODS: Porcine tibiae (apparent bone mineral density, 1.3 g/cm(2)) and human tendon allografts were divided into 3 matched groups of 6 specimens each before cyclic (500 cycles, 50-250 N, 1 Hz) and load-to-failure (20 mm/min) tests. RESULTS: The BioScrew XtraLok (210.9 +/- 54.9 N/mm) and the 35-mm Delta Screw (224.3 +/- 43.7 N/mm) displayed superior stiffness to the RetroScrew System (114.1 +/- 23.3 N/mm) (P = .0004) during cyclic testing. The BioScrew XtraLok (1.0 +/- 0.2 mm) and the Delta Screw (0.9 +/- 0.2 mm) also displayed less displacement during cyclic testing than the RetroScrew System (1.8 +/- 0.5 mm) (P = .001). During load-to-failure testing, the BioScrew XtraLok withstood greater loads (1436.3 +/- 331.3 N) (P = .001) and displayed greater stiffness (323.6 +/- 56.8 N/mm) (P = .002) than the 35-mm Delta Screw (load, 1042.2 +/- 214.4 N; stiffness, 257.2 +/- 22.2 N/mm) and the RetroScrew System (load, 778.7 +/- 177.5 N; stiffness, 204.4 +/- 52.9 N/mm). CONCLUSION: The BioScrew XtraLok with instrumented tensioning displayed superior fixation to the RetroScrew System and the 35-mm Delta Screw applied with manual tensioning. CLINICAL RELEVANCE: The BioScrew XtraLok may provide superior soft tissue graft-tibial tunnel fixation. Further in vitro studies using human tissue and in vivo clinical studies are needed.

Absorbable Implants↗
PubMed2005

Influence of thread design on bioabsorbable interference screw insertion torque during retrograde fixation of a soft-tissue graft in synthetic bone.

PURPOSE: Bioabsorbable interference screw design may influence biomechanical characteristics. This study compared the insertion torque and load at failure characteristics of 2 types of screws during retrograde fixation of a soft-tissue graft. TYPE OF STUDY: Biomechanical study. METHODS: Eight matched pairs of doubled 100-mm long tibialis anterior allografts were prepared and fixed in appropriately sized tunnels created in 10 lb/ft 3 (0.16 g/cm3) dense synthetic bone blocks using screws of similar length and root and thread diameter designed with either a large buttress thread with a smaller taper or small buttress thread with a larger taper. Insertion torque was measured at one-third, two-thirds, and full screw insertion. After the graft fixation constructs were mounted in a servohydraulic-testing device with the loading axis aligned directly with the tunnel and preloaded to 25 N, they were cycled 3 times from 0 to 50 N, and then subjected to a 20 mm/minute traction force to failure. RESULTS: All constructs failed by graft slippage past the screw. Mean maximum load at failure (360.5 +/- 68 N v 341.6 +/- 58 N, P = .2) and stiffness (63.6 +/- 16 N/mm 2 v 66.4 +/- 14 N/mm 2 , P = .89) was similar between constructs fixed with a large buttress thread small-taper screw and small buttress thread large-taper screw, respectively. The small buttress thread screw with a large taper displayed greater mean insertion torque at one-third insertion (4.1 +/- 0.57 in-lb v 3.2 +/- 0.49 in-lb, P = .03), whereas the large buttress thread screw with a small taper displayed greater mean insertion torque at full insertion (11.1 +/- 0.74 in-lb v 9.4 +/- 1.3 in-lb, P = .012). Mean differences were not observed at two-thirds screw insertion (P = .12). CONCLUSIONS: Large buttress thread small-taper screws displayed biomechanical fixation characteristics comparable to small buttress thread large-taper screws. CLINICAL RELEVANCE: Given reports of superior screw-graft-bone tunnel contact area, these biomechanical results suggest that use of a large buttress screw with a small taper may be preferable for retrograde soft-tissue graft fixation.

Absorbable Implants↗
PubMed2005

Soft-tissue interference fixation: bioabsorbable screw versus metal screw.

PURPOSE: To compare the biomechanical properties of eccentrically positioned bioabsorbable and titanium interference screws for quadrupled hamstring tendon graft (QHTG) fixation. TYPE OF STUDY: In vitro, biomechanical study. METHODS: In 10 paired cadaveric tibiae and femurs (mean age, 66.5 years; range, 53 to 81 years), QHTG fixation was performed in tunnels sized to within 0.5 mm of QHTG diameter using either a titanium (RCI; Smith & Nephew Donjoy, Carlsbad, CA) or a bioabsorbable (BioScrew; Linvatec, Largo, FL) screw of equal size. Constructs then underwent biomechanical load-to-failure testing on a servo-hydraulic device at 20 mm/min. RESULTS: Load at failure was greater for femoral-side QHTG fixation using the bioabsorbable screw than the titanium screw (486 +/- 223.7 N v 246 +/- 99.1 N, P = .006); however, displacement did not differ (P = .81). There were no statistically significant differences between groups for tibial side load at failure (P = .54), stiffness (P = .44), or displacement (P = .50). Screw thread-induced graft laceration was more frequently observed in the titanium screw group (9 of 10 grafts during femoral-side testing, 0 of 10 grafts during tibial-side testing) than in the bioabsorbable screw group (0 of 10 grafts during femoral-side testing, 1 of 10 grafts during tibial-side testing). CONCLUSIONS: BioScrew interference screw fixation was comparable or superior to RCI titanium interference screw fixation. BioScrew interference screw fixation also produced less screw thread-induced laceration of the QHTG during load-to-failure testing. CLINICAL RELEVANCE: Use of a biodegradable interference screw positioned directly against a soft-tissue graft provides fixation properties similar to those of a metal interference screw.

Absorbable Implants↗
PubMed2005

Single femoral socket double-bundle anterior cruciate ligament reconstruction using tibialis anterior tendon: description of a new technique.

The native anterior cruciate ligament (ACL) has been shown to consist of 2 functional bundles with independent behavior throughout range of knee motion. Conventional arthroscopic ACL reconstruction techniques selectively recreate the anteromedial bundle of the native ACL only. Numerous studies have reported the failure to restore normal knee kinematics in an ACL-deficient knee using a single-bundle reconstruction. It has been suggested that by reconstructing both the anteromedial and posterolateral bundles of the ACL, more normal knee kinematics may be achieved. Several authors have described surgical techniques to recreate the 2 functional bundles and they range from using 2 femoral tunnels to using a single femoral tunnel with the other bundle passed over the top. This article describes a new technique of recreating the 2 functional bundles of the ACL with tibialis anterior tendon allograft using a single femoral socket.

Anterior Cruciate Ligament↗
PubMed2004

Patient outcomes following T-Fix meniscal repair and a modifiable, progressive rehabilitation program, a retrospective study.

INTRODUCTION: This retrospective study presents clinical patient outcomes following meniscal repair using T-Fix devices and a modifiable, progressive rehabilitation program. MATERIALS AND METHODS: Fifty-two patients (35 males and 17 females) with a mean age of 26.7 years (range 13-50 years) representing all of the patients who underwent arthroscopic meniscal repair (43 medial meniscus, 12 lateral meniscus) over a 3-year period by the same surgeon (D.C.) (55 menisci) participated in this study. Thirty-two of the patients (62%) had an associated ACL tear. All patients with an ACL tear underwent reconstruction (tibialis anterior allograft) at the time of meniscal repair. All meniscal tears were located in either the red-red zone (29) or the red-white zone (26). All patients who underwent meniscal repair participated in a modifiable (based on meniscal tear size, type, and location) progressive rehabilitation program. Operative notes and photographs were reviewed to identify the meniscal tear location, tear type, tear length, and the number of T-Fix devices used. Orthopedic clinic and physical therapy reports were also reviewed for postoperative range of motion, knee joint effusion, knee joint pain, McMurray test findings, and single-leg broad-jump test performance (90% bilateral equivalence goal). The average postoperative clinical follow-up period was 10.3 months (range 4-24 months). RESULTS: Most (22/23, 96%) patients who underwent meniscal repair alone displayed excellent results. All patients (32/32, 100%) who underwent combined ACL reconstruction-meniscal repair displayed excellent results. During an acute event such as a sudden directional change while running or contact with another player, 5 of these patients re-injured their meniscus at the repair site in conjunction with tearing the reconstructed ACL at 12+/-3 months following the index surgical procedure. Each of these 1-2 cm meniscal tears had been previously repaired with two T-Fix devices. CONCLUSION: The T-Fix device used in combination with a modifiable progressive rehabilitation program produced excellent clinical patient outcomes among this patient group.

Adolescent↗
PubMed2004

Insertion torque pullout strength relationship of soft tissue tendon graft tibia tunnel fixation with a bioabsorbable interference screw.

PURPOSE: The purpose of this study was to evaluate the relationship between insertion torque and the biomechanical characteristics of soft tissue tendon graft tibia fixation with a bioabsorbable interference screw. TYPE OF STUDY: Biomechanical study. METHODS: Doubled tibialis anterior allografts (n = 20, length = 100 mm, diameter = 9 mm) prepared for anterior cruciate ligament (ACL) reconstructions were divided into 3 groups. Maximum insertion torque was measured as grafts were fixed by the same surgeon with a 10-mm diameter, 35-mm long screw in a 7-mm diameter tunnel (dilated to 9 mm) created in either 0.16 or 0.32 g/cm3 dense synthetic bone or cadaveric tibiae (0.84 +/- 0.15 g/cm2). Tensile testing to construct failure was then performed. RESULTS: All constructs failed by tunnel pullout. Higher density synthetic bone had greater load at failure than lower density synthetic bone (486.6 +/- 83.8 v 271.6 +/- 52.6 N, P <.0001) and a slightly greater proportion of variance could be explained in synthetic bone (R2 = 0.74, P <.0001) than in cadaveric tibiae (R2 = 0.64, P =.017). Higher density synthetic bone displayed greater stiffness than lower density synthetic bone (68.1 +/- 21.6 v 37.7 +/- 11.2 N/mm, P =.012) and a higher proportion of variance could be explained in cadaveric tibiae (R2 = 0.72, P =.008) than in synthetic bone (R2 = 0.48, P =.012). Greater insertion torque levels were seen in higher density synthetic bone (2.97 +/- 0.35 v 1.24 +/- 0.06 Nm, P <.0001) than in lower density synthetic bone, and a higher proportion of variance could be explained in synthetic bone (R2 = 0.94, P <.0001) than in cadaveric tibiae (R2 = 0.74, P =.006). CONCLUSIONS: Strong relationships were evident between insertion torque, bone mineral density (BMD) and load to failure across constructs. Differences between the synthetic bone groups and cadaveric tibiae, however, suggest the influence of mixed cortical and cancellous bone, nonuniform structural patterning, and differing BMD levels and distributions in the cadaveric tibiae. CLINICAL RELEVANCE: Soft tissue graft tibial tunnel fixation is directly related to insertion torque and BMD. Synthetic models with mixed bone characteristics are needed to more accurately depict human tibiae during fixation testing.

Absorbable Implants↗
PubMed2004

Posterolateral corner reconstruction using a hamstring allograft and a bioabsorbable tenodesis screw: description of a new surgical technique.

Capsuloligamentous posterolateral corner knee joint deficiencies cause increased anterior cruciate ligament forces during internal knee rotation and increased posterior cruciate ligament forces during external knee rotation. Undiagnosed posterolateral corner knee joint injury in combination with anterior cruciate ligament or posterior cruciate ligament injury can lead to failure of anterior cruciate ligament or posterior cruciate ligament reconstruction. The purpose of this technical note is to present a new posterolateral corner reconstruction technique for treating patients with chronic capsuloligamentous posterolateral corner deficiency. The technique uses a bioabsorbable tenodesis screw and a hamstring allograft to reconstruct the popliteofibular and lateral collateral ligaments.

Absorbable Implants↗
PubMed2004

Tendon graft fixation in ACL reconstruction: in vitro evaluation of bioabsorbable tenodesis screw.

BACKGROUND: Conventional ACL reconstruction requires sufficient tibial bone quality for secure graft fixation. We evaluated the mechanical characteristics of a supplemental tenodesis screw in cadaveric specimens. MATERIAL AND METHODS: One group of 7 specimens from 7-paired tibiae was randomly assigned to undergo tibialis anterior tendon graft-bone tunnel fixation with a bioabsorbable interference screw, using conventional ACL reconstruction techniques. The other group of 7 specimens underwent the same procedure supplemented with a bioabsorbable tenodesis screw. All specimens were subjected to pullout testing on a servo hydraulic device. RESULTS: Specimens in the supplemental fixation group had double the load to failure (tenodesis = 467 (SD 184) N, control group = 223 (SD 66) N, p = 0.02) and were also one-third stiffer (tenodesis = 31 (SD 13) N/mm, control group = 21 (SD 6) N/mm, p = 0.03) than the specimens in the conventional fixation group. INTERPRETATION: Supplemental bioabsorbable tenodesis screw fixation may be advantageous for primary reconstruction in patients with low tibial bone mineral density or during revision procedures. By providing secure soft tissue graft-tibia fixation during the early phase after ACL reconstruction, supplemental tenodesis fixation may enable patients to participate safely in more intense, early rehabilitation.

Absorbable Implants↗
PubMed2004

A biomechanical comparison of initial soft tissue tibial fixation devices: the Intrafix versus a tapered 35-mm bioabsorbable interference screw.

BACKGROUND: Biomechanical testing of the Intrafix device has not been performed using human tibiae. HYPOTHESIS: The Intrafix device would provide comparable or superior tibial fixation of a quadrupled hamstring tendon graft to a 35-mm-long bioabsorbable interference screw. STUDY DESIGN: In vitro, biomechanical study. METHODS: Eight paired human tibiae and 16 quadrupled hamstring tendon grafts were divided into 2 groups. Each quadrupled hamstring tendon graft was fixed in a tunnel sized to 0.5 mm graft diameter with either an Intrafix device or a screw. RESULTS: Displacement at failure was greater in the Intrafix group (17.3 +/- 4.6 mm versus 10.9 +/- 4.4 mm, P =.002). Load at failure (796 +/- 193 N versus 647 +/- 269 N), stiffness (49.2 +/- 21.9 N/mm versus 64.5 +/- 22 N/mm), and bone mineral density (0.74 +/- 0.15 gm/cm(3) versus 0.74 +/- 0.14 gm/cm(3)) did not display significant differences for the Intrafix device and the screw, respectively (P >.05). CONCLUSIONS: Displacement at failure was greater for the Intrafix device. CLINICAL RELEVANCE: Increased displacement at failure for the Intrafix group suggests slippage from sheath channel deployment. Concentric fixation may not occur when less than optimal tibial bone mineral density increases the difficulty of attaining precise sheath deployment and quadrupled hamstring tendon graft strand alignment.

Bone Screws↗