The effect of inclination angle on the strength of vertical mattress configuration for meniscus repair.

PURPOSE: Vertical mattress configuration is the strongest of all other configurations and the repairing devices of meniscus repair. The purpose was whether increasing the inclination angle between two strands of the vertical mattress configuration by increasing the amount of meniscus tissue captured would enhance the initial strength of the construction. METHODS: A 2-cm long anteroposterior vertical longitudinal incision was created in two groups of bovine medial menisci. In the first group, the distance between the two vertical suture strands and the vertical horizontal sutures on the capsular side of the meniscal lesion was 2 mm (Group 1). In the second group, the distance was 5 mm (Group 2). The following repair specimens underwent cyclic loading prior to loading the failure testing. The endpoints included ultimate failure load (N), stiffness (N/mm) and cyclic displacement (mm) after the 100 cycles and the mode of failure. RESULTS: Group 1 (2 mm) (90.7 (±19.9) N) had lower ultimate load than Group 2 (5 mm) (120.8 (±24.5)) (P < 0.05). Stiffness and displacements during the cycling were not different between the groups (n.s.). All specimens failed by suture rupture. CONCLUSION: Increased inclination angle with increased distance between the two vertical suture strands on the capsular side of the meniscal lesion resulted in higher failure load compared to control group with lower inclination angle and distance on the capsular side.

ACL double bundle linked cortical-aperture tibial fixation: a technical note.

INTRODUCTION: The purpose of this technical note is to describe the tibial fixation characteristics for an all-inside anatomic anterior cruciate ligament (ACL) reconstruction method that links extra-cortical button suspensory and aperture fixation replicating double bundle soft tissue graft function in single femoral and tibial sockets. MATERIALS AND METHODS: A 55° drill guide aligned guidewires in the ACL footprint center of 8 porcine tibiae (mean apparent bone mineral density = 1.15 g/cm(2)). A Flipcutter created 27 mm sockets and 15 mm guidewire channels. Advancement sutures seated porcine soft tissue graft-PEEK implants to achieve both socket aperture and extra-cortical button suspensory fixation. Potted specimens were loaded into a 6º of freedom clamp with the servohydraulic loading vector in direct socket alignment. Constructs were pre-loaded to 25 N, underwent 10 pre-conditioning cycles (0-50 N, 0.5 Hz), and 500 submaximal loading cycles (50-250 N, 1 Hz) prior to load to failure testing (20 mm/min). Mode of failure was recorded. Descriptive statistical analysis was performed. RESULTS: All specimens survived the biomechanical test protocol. Displacement during cyclic loading was 2.8 ± 0.9 mm, yield load was 475.2 ± 36 N, ultimate load at failure was 671.4 ± 98 N, stiffness was 127.5 ± 15 N/mm. The most common failure mode was suture pulling through the soft tissue graft. CONCLUSIONS: This ACL reconstruction method combines the high ultimate load to failure and low graft slippage of extra-cortical button suspensory fixation with the high stiffness of aperture fixation. Biomechanical test findings were comparable or better to previous reports for displacement during submaximal loading, ultimate failure load, and construct stiffness. Based on current understanding of soft tissue graft ACL reconstruction biomechanics, this fixation method should enhance graft-bone socket integration during healing, facilitate long-term graft survival, and improve patient outcomes. Clinical studies are needed to confirm in vivo efficacy.

The Effect of Supplementary Staple Fixation on Biomechanical Properties of Soft Tissue Graft Tibial Fixation in Anterior Cruciate Ligament Reconstruction.

This study aimed to test and compare the biomechanical properties of three tibial fixation methods of anterior cruciate ligament (ACL) tendon grafts under cyclic load and load-to-failure testing in the bovine proximal tibiae, comprising (1) staple fixation alone, (2) interference screw fixation alone, and (3) interference screw fixation with a supplementary staple. Twenty-four bovine tibiae used in the study were divided into three groups (eight proximal tibiae in each group) based on tibial fixation methods of ACL tendon grafts: group A (a spiked ligament staple alone), group B (a cannulated interference screw alone), and group C (a cannulated interference screw with a supplementary staple). Each graft fixation was exposed to cyclic loading conditions. Significant differences were determined in failure load among the three groups (p = 0.008). The mean failure load was significantly higher in group B (717.04 ± 218.51 N) than in group A (308.03 ± 17.22 N) (p = 0.006). No significant differences were observed among the groups regarding axial stiffness (p = 0.442). Cyclic displacement differed significantly among the three groups (p = 0.005). In pairwise comparisons, the mean cyclic displacement was significantly higher in group A (8.22 ± 3.24 mm) compared with group C (1.49 ± 0.41 mm) (p = 0.005). Failure displacement varied considerably among the groups (p = 0.037). Although group B (15.53 ± 6.43 mm) exhibited a greater mean failure displacement than both group A (4.9 ± 0.75 mm) and group C (8.84 ± 4.65 mm), these differences did not reach statistical significance (p = 0.602 and p = 0.329, respectively). Interference screw fixation alone and supplementary staple fixation have biomechanically similar characteristics in terms of initial strength and stiffness of tibial ACL soft tissue graft fixation. Regardless of staple use, an interference screw with the same diameter as the tibial tunnel can ensure sufficient tensile strength in tibial ACL graft fixation.

Horizontal suture placement influences meniscal repair fixation strength.

PURPOSE: This in vitro biomechanical study investigated the influence of horizontal suture placement distance from the medial meniscal lesion repair site on fixation characteristics during submaximal cyclic and load to failure test conditions. METHODS: Eighteen cadaveric (20-45 years of age) medial menisci with intact joint capsules were harvested within 24-48 h after death and divided into two groups of 9 specimens each for biomechanical testing. A 2.0-cm-long antero-posterior vertical longitudinal lesion was created with a #15 scalpel 2.0-3.0 mm from the outer edge of each meniscus. Menisci were repaired using #2-0 suture material with two horizontal suture loops placed either 1.0 mm (Group 1) or 3.0 mm (Group 2) from the lesion site. Following repair, the lesion was extended completely through the meniscal horns so that no tissue secured the repair, only the two horizontal suture loops representing a "worst-case" testing scenario. Following repair, specimens were placed in a servo hydraulic device using a pair of 1.2-mm-diameter steel wire loops and underwent submaximal cyclic loading between 5 and 50 N (1 Hz) for 500 cycles prior to load to failure testing (5 mm/min crosshead speed, 20 Hz data collection). An alpha level of P < 0.05 was selected to indicate statistical significance. RESULTS: Five of nine (55.6 %) Group 1 specimens did not complete submaximal cyclic testing. All Group 2 specimens completed submaximal cyclic testing (Fisher's exact test P = 0.029). Statistically significant mean group differences were not observed for displacement during submaximal cyclic loading (Group 1 = 5.0 ± 1.5 mm and Group 2 = 5.7 ± 1.6 mm) or for construct stiffness during load to failure testing (Group 1 = 50.1 ± 6.3 N/mm and Group 2 = 52.6 ± 11.9 N/mm). Group 2 displayed greater mean load at failure (112.1 ± 40.8 N vs. 72.7 ± 11.2 N, P = 0.02) and mean displacement at failure (11.1 ± 2.2 mm vs. 7.6 ± 1.4 mm, P = 0.03) than Group 1. CONCLUSIONS: Horizontal sutures placed slightly farther away from the meniscus lesion displayed superior repair fixation than sutures placed closer to the lesion. The superior biomechanical meniscal repair fixation provided by capturing greater tissue volume may enable safe earlier participation in functional exercise activities. Studies are needed to verify these findings in vivo.

Tibial Press-Fit Fixation Technique in Anterior Cruciate Ligament Reconstruction.

Implant-free press-fit tibial fixation technique has gained popularity recently due to the problems in bone tunnel expansion, defect, and revision surgery due to the tibial fixation material preferred in anterior cruciate ligament surgery. Patellar tendon-tibial bone autograft offers several advantages in anterior cruciate ligament reconstruction. We describe a tibial tunnel preparation method and the use of patellar tendon-bone graft in the implant-free tibial press-fit technique. We call this the Kocabey press-fit technique.

Tibial Press-Fit Fixation Technique in Anterior Cruciate Ligament Reconstruction Surgery.

Implant-free press-fit tibial fixation technique has recently gained popularity in anterior cruciate ligament reconstruction because it does not cause tunnel widening, does not cause complications associated with additional fixation materials, allows bone-to-bone healing, and does not cause defects in revision surgery. Bone-patellar tendon autograft offers the advantage of direct bone-to-bone integration of the graft, and anterior knee pain is less expected than bone-patellar tendon-bone autograft. This technical report includes details of arthroscopic ACL reconstruction of patellar tendon-tibial tubercle bone autograft distal press-fit fixation technique. We call this the Kocabey distal press-fit technique.

Tendon-grasping strength of various suture configurations for rotator cuff repair.

PURPOSE: The purpose of the present study is to evaluate the mechanical performance and initial strength of the arthroscopic Mason-Allen, double mattress, inclined Mason-Allen, and lasso loop stitch configurations. METHODS: Using 36 sheep infraspinatus tendons, tendon widths and thicknesses were measured with a digital caliper to confirm standardization of the tendons. Four different stitch configurations (Mason-Allen, inclined Mason-Allen, double mattress, and lasso loop) were biomechanically tested with cyclic loading followed by load to failure testing. The cyclic elongation, peak-to-peak displacement, ultimate tensile strength, stiffness, and mode of failure were recorded. RESULTS: Mean tendon widths and thicknesses were statistically the same. The lasso loop (0.7 ± 0.1 mm) demonstrated a mean cyclic elongation greater than the Mason-Allen (0.5 ± 0.3 mm) and double mattress (0.5 ± 0.3 mm) groups (P = 0.011; P = 0.013). No differences were found in ultimate failure load, stiffness, and peak-to-peak displacement for the Mason-Allen (mean 99 ± 42 N, 39 ± 9 N/mm, 0.6 ± 0,1 mm), inclined Mason-Allen (113 ± 52 N, 44 ± 14 N/mm, 0.5 ± 0.1 mm), double mattress stitch (119 ± 68 N, 45 ± 10 N/mm, 0.5 ± 0.1 mm), or lasso loop (100 ± 38 N, 42 ± 7 N/mm, 0.5 ± 0.1 mm) groups (n.s.). Each specimen failed at the suture-tendon interface. Three specimens (two Mason-Allen and one inclined Mason-Allen) failed during cyclic testing. CONCLUSION: Conventional Mason-Allen configuration can be applied with double-loaded suture anchor safely. Recent modifications of the configurations offer no biomechanical advantage.

Meniscal repair using large diameter horizontal sutures increases fixation strength: an in vitro study.

PURPOSE: the purpose of this study was to compare the mechanical characteristics of meniscal repair fixation using horizontal sutures and two different diameter sutures under submaximal cyclic and load to failure test conditions. METHOD: a 2-cm long anteroposterior vertical longitudinal incision was created in two groups of bovine medial menisci. Lesions were repaired using either #2-0 (Group 1), or #2 (Group 2) Fiberwire suture. Following repair, the lesion was extended through the posterior and anterior meniscal horns so that no tissue secured the repair site. Specimens underwent submaximal cyclic (5-50 N at 1 Hz for 500 cycles) and load to failure testing (5 mm/min crosshead speed) in a servo hydraulic device. Specimen failure mode was verified by the primary investigator. An alpha level of P < 0.05 was selected to indicate statistical significance. RESULTS: group 2 displayed greater load at failure (132.1 ± 54.4 N) than Group 1 (91.9 ± 26.2 N) (P = 0.02). Group 2 also displayed greater stiffness (47.1 ± 8.3 N/mm) than Group 1 (38.5 ± 10.2 N/mm) (P = 0.03). The failure mode for all specimens was suture pull-through the meniscal tissue. Larger diameter suture provided superior mechanical meniscal fixation. CONCLUSION: if horizontal suture would be used in meniscal repair, the most suitable larger diameter suture should be used.

Postoperative rehabilitation and outcomes following arthroscopic isolated meniscus repairs: A systematic review.

OBJECTIVES: The purpose of this study was to review the current literature on rehabilitation protocols following arthroscopic meniscus repair. METHODS: A systematic literature review was performed of Medline, Scopus, and Web of Science databases to identify relevant articles from January 1990 to April 2019. Search terms were (meniscus OR meniscal repair) AND (repaired OR repair) AND (rehabilitation OR physiotherapy OR physical therapy). Each study was independently scored for methodological research quality level using the Modified Coleman Methodology Score (MCMS). The following variables were extracted from each study: publication year, study type, evidence level, subject demographics, injury mechanism, meniscus tear type, surgical procedure, rehabilitation program [immobilization, weight bearing, ROM progression, therapeutic exercises, length of follow-up, patient-reported outcome measurements, return to sport timing/criteria and failure rate/criteria. RESULTS: Eighteen studies met the inclusion criteria. The overall MCMS was moderate 59.5 ± 11.7 (range = 42-90). The average MCMS score for postoperative rehabilitation was 4.7 ± 1.18. Only 1 (5.6%) study was a prospective randomized controlled trial and 14 studies (78%) had retrospective designs. Fourteen (78%) studies suggested that return to sports should occur between 3 and 6 months post-surgery. Early range of motion and immediate weight-bearing had no influence over patient-reported outcomes or failure rates for vertical meniscus tear repairs. CONCLUSION: Low MCMS scores, primarily retrospective study designs and poorly described postoperative rehabilitation protocols made it difficult to design an evidence-based therapeutic rehabilitation program for patients following arthroscopic repair of an isolated meniscus tear. An arthroscopic isolated meniscal tear repair rehabilitation protocol is being attempted to present based on a synopsis of existing evidence.

An Alternative Femoral Fixation in All-Inside Anterior Cruciate Ligament Reconstruction: A Solution for Preventing Possible Graft Loosening.

The aim of this surgical Technical Note is to search for a way to prevent possible graft loosening in all-inside anterior cruciate ligament (ACL) reconstruction. We used a fixed-loop cortical suspensory device on the femoral end and a suspensory cortical fixation technique and sutures on the tibial end. Then we flexed the knee for 150 cycles, reexamined the tightness of the ACL graft, and compared it with the initial tightness. Loosening of the ACL graft, which is suggested to be related to suspensory cortical fixation, could be prevented using the button system on the femoral end and tightening the suspensory cortical fixation on the tibial end.

Relationship between synovial fluid and plasma manganese, arginase, and nitric oxide in patients with rheumatoid arthritis.

Nitric oxide (NO) participates in the pathogenesis of inflammatory reactions in many autoimmune diseases such as rheumatoid arthritis (RA). There is a reciprocal pathway between arginase and nitric oxide synthase (NOS) for NO production, and Mn is required for arginase activity and stability. To investigate whether NO production related with the arginine-nitric oxide pathway in patients with RA, we measured synovial fluid and plasma nitrite (NOx) levels, arginase activities, and its cofactor manganese (Mn) concentrations in 21 RA patients and 13 healthy control subjects. Plasma albumin levels were measured as an index of nutritional status. NOx levels were determined after the reduction of nitrates to nitrites using the Griess reaction. Whereas, synovial fluid arginase activities and Mn levels were found to be significantly lower (p<0.001, p<0.001, respectively), plasma arginase activities and Mn levels were similar in patients with RA when compared to the control subjects. Plasma and synovial fluid NO levels were similar in patients with RA and in healthy subjects (p>0.05, p>0.05, respectively). There were significantly positive correlations between synovial fluid and plasma arginase activities vs Mn content (r=0.543, p=0.011; r=0.516, p=0.017, respectively) and significantly negative correlations between synovial fluid and plasma NO levels vs arginase activities (r=-0.497, p=0.022; r=-0.508, p=0.019 respectively) in the patients group. Our results indicate that the lower concentration of synovial fluid Mn could cause lower arginase activity and this could also upregulate NO production by increasing L-arginine content in patients with RA.

Free nerve endings and morphological features of the ligamentum capitis femoris in developmental dysplasia of the hip.

A conflict exists on whether the ligamentum capitis femoris has the neuro-morphological structures required for nociception or proprioception of the hip joint. Therefore, we investigated the morphological features and the presence of mechanoreceptors in 24 ligamentum capitis femoris biopsies obtained at open reduction in patients with developmental dysplasia of the hip. Of these 24 hips, 16 were completely dislocated and eight were subluxated. The mean age was 33.8 months (range 13-52 months) at the time of surgery. En bloc ligamentum capitis femoris and pulvinar were taken for biopsy specimen. Ligamentum capitis femoris was dissected and the weight of each ligament was determined using a highly sensitive balance. Specimens were stained with hematoxylin and eosin and Masson trichrome for routine histolopathological evaluation and examined immunohistochemically using monoclonal antibody against S-100 protein. All specimens were graded on a four-grade system according to the amount of coarse-thick collagen bundles and hyalinization. The mean number and type of mechanoreceptors of each specimen were recorded. When the mean age, the patient's weight and the ligamentum capitis femoris weight of each group (completely dislocated vs. subluxated) were compared, there were no significant differences. In the ligamentum capitis femoris of the dislocated hips, the cells were irregularly distributed, had different shapes, and appeared to be in different stages of functional activity. The collagen fiber bundles were thicker than in the subluxated hips, distributed and of varied thickness. The elastic fibers of the dislocated hips were thicker and more numerous than those in the subluxated hips. We found a significant difference between the two groups with regard to the grade of collagen and hyalinization of ligamentum capitis femoris (P<0.004). We found type IVa, free nerve endings in 16 of 24 samples of ligamentum capitis femoris. The 66.6% presence of free nerve endings in the ligamentum capitis femoris suggests a role in nociception/proprioception of the hip in developmental dysplasia of the hip. Interestingly, the percentage and the mean numbers of free nerve endings containing ligamentum capitis femoris were similar in completely dislocated hip group and the subluxated group (62.5 vs. 75%, 12.13+/-9.07 vs. 9.37+/-9.24, respectively). We conclude that the morphological features of ligamentum capitis femoris are influenced by the severity of developmental dysplasia of the hip, whereas the distribution of free nerve endings are not influenced.

[Articular cartilage lesions in unstable knees]. / Instabil dizlerde eklem kikirdak lezyonlari.

OBJECTIVES: The purpose of this retrospective analysis was to evaluate the management of chondral defects in knees with anterior cruciate ligament (ACL) disruption. METHODS: Twenty-seven patients (mean age 35 years; range, 20 to 48 years) were randomized to osteochondral autologous transplantation (OAT, n=14) or a microfracture (MF, n=13) procedure together with ACL reconstruction in the same session for symptomatic lesions of the articular cartilage in ACL-deficient knees. The mean follow-up period was 34 months (range 24 to 53 months) in the OAT group, and 49 months (range 24 to 97 months) in the MF group. Patients were evaluated using the Lysholm and IKDC 2000 (International Knee Documentation Committee) scores. RESULTS: Patients undergoing OAT had a mean IKDC 2000 score of 49.2 (range 30.1 to 64.7), and Lysholm score of 43.4 (range 33.2 to 58.9) preoperatively. At the end of follow-up, these scores increased to 93.3 (range 73 to 98) and 97.5 (range 38.7 to 100), respectively. In the MF group, the mean IKDC 2000 score increased from 53.6 (range 47.1 to 64.7) to 72.3 (range 62.8 to 94), and the mean Lysholm score increased from 48 (range 38.2 to 58.9) to 81.3 (range 72.7 to 100). CONCLUSION: Treatment of chondral lesions should be added to ACL reconstruction in unstable knees secondary to ACL deficiency.

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.

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.

Salvage rotator cuff repair using a biotenodesis screw.

Rotator cuff tear fixation can be difficult when humeral head bone stock is poor as a result of osteopenia or osteoporosis. This technical note describes biotenodesis screw use to achieve effective fixation after 2 previous attempts at implanting suture anchors failed.

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.

Anatomy, function, and rehabilitation of the popliteus musculotendinous complex.

We present a clinical commentary of existing evidence regarding popliteus musculotendinous complex anatomy, biomechanics, muscle activation, and kinesthesia as they relate to functional knee joint rehabilitation. The popliteus appears to act as a dynamic guidance system for monitoring and controlling subtle transverse- and frontal-plane knee joint movements, controlling anterior-posterior lateral meniscus movement, unlocking and internally rotating the knee joint (tibia) during flexion initiation, assisting with 3-dimensional dynamic lower extremity postural stability during single-leg stance, preventing forward femoral dislocation on the tibia during flexed-knee stance, and providing for postural equilibrium adjustments during standing. These functions may be most important during mid-range knee flexion when capsuloligamentous struCtures are unable to function optimally. Because the popliteus musculotendinous complex has attachments that approximate the borders of both collateral ligaments, it has the potential for providing instantaneous 3-dimensional kinesthetic feedback of both medial and lateral tibiofemoral joint compartment function. Enhanced popliteus function as a kinesthetic knee joint monitor acting in synergy with dynamic hip muscular control of femoral internal rotation and adduction, and ankle subtalar muscular control of tibial abduction-external rotation or adduction-internal rotation, may help to prevent athletic knee joint injuries and facilitate recovery during rehabilitation by assisting the primary sagittal plane dynamic knee joint stabilization provided by the quadriceps femoris, hamstrings, and gastrocnemius.

[The results of open surgical treatment in patients with chronic refractory lateral epicondylitis]. / Kronik, konservatif tedaviye dirençli lateral epikondilitte açik cerrahi tedavi sonuçlari.

OBJECTIVES: We evaluated the clinical and subjective functional results of open surgical treatment in patients with chronic refractory lateral epicondylitis. METHODS: Eleven patients (7 females, 4 males; mean age 42 years, range 29 to 56 years) underwent open surgical treatment for chronic refractory lateral epicondylitis. All the patients had received conservative treatment for at least a year without favorable response. Surgical procedure included release of the lateral extensor origin, excision of the degenerative tissue, decortication or drilling of the anterior lateral condyle, and repair of the extensor tendons. The results were evaluated according to the criteria proposed by Verhaar et al. The mean follow-up was 29 months (range 18 to 45 months). RESULTS: The results were excellent or good in 10 patients (90.9%) and acceptable in one patient (9.1%). The mean time to return to work was two months. Nine patients were free of pain in the forearm in the postoperative third month. No wound-related complications were encountered. On subjective evaluations, 10 patients reported full satisfaction, and one patient reported partial satisfaction with the result of the treatment. CONCLUSION: Open surgical procedure including release of the origins of the common extensor tendons and excision of the degenerative tissue yields favorable results in the treatment of patients with chronic refractory lateral epicondylitis.

[The effect of the tibial tunnel fixation level on the results of cyclic loading in anterior cruciate ligament reconstruction]. / On çapraz bag rekonstrüksiyonunda tibial tünel tespit seviyesinin tekrarlayici yüklenme testi sonuçlarina etkisi.

OBJECTIVES: This study was designed to compare the biomechanical characteristics of non-anatomic (far from joint) and anatomic (close to joint) levels of tibial tunnel fixation with soft tissue graft using a soft tissue interference screw in anterior cruciate ligament (ACL) reconstruction. METHODS: Twelve bovine tibiae and digital extensor tendons were divided into two homogeneously equal groups after removing soft tissues. Tibial tunnels were prepared with a 7-mm drill with the use of an ACL guide adjusted to 45 degrees . Each tunnel was then dilated to 9 mm in 0.5 mm increments. Digital extensor tendons were fixed at non-anatomic (group I) or anatomic (group II) tibial tunnel levels with a soft tissue metal interference screw, 9 x 30 mm in size. All the specimens were cycled 500 times from 50 to 250 N with 1 Hz frequency in a servo-hydraulic testing machine followed by ultimate load at-failure testing at a rate of 20 mm/min. Statistical analyses were made using the Mann-Whitney U-test. RESULTS: The mean screw insertion torque values were 8.2+/-2.4 Nm and 7.8+/-2.3 Nm in groups I and II, respectively (p=0.88). The mean values of graft displacement (1.9+/-0.75 mm versus 2.2+/-1.2 mm, p=0.63) and stiffness (132.72+/-10.93 N/mm versus 125.14+/-15.93 N/mm, p=0.63) did not differ significantly. CONCLUSION: The biomechanical properties of ACL reconstruction with soft tissue graft fixation using a soft tissue interference screw are not influenced by the level of tibial tunnel fixation.