ABSTRACT
Rotator cuff tears are a major cause of morbidity. Following rotator cuff tears, muscle atrophy and fatty infiltration begin in the tissue, limiting repair potential and leading to a higher re-tear rate and a worse functional outcome. We evaluated whether fatty degeneration resulting from a complete supraspinatus tear with retraction is associated with an injury to the suprascapular nerve. Four skeletally mature New Zealand white rabbits were randomized to receive an index procedure on either their right or left shoulder with the opposite shoulder serving as a control. At the index procedure, the supraspinatus tendon was transected at its insertion and allowed to retract. At 3 months, the rabbits were euthanized, and both supraspinatus muscles were harvested. The specimens were then examined with confocal microscopy and histology. Atrophy was grossly visible in all four test muscles, and fatty infiltration was confirmed with osmium tetroxide staining. In all four rabbits, the degree of denervation (p = 0.71) and partial denervation (p = 0.91) was not significantly different between control and experimental muscle. Rotator cuff tear does not affect the motor endplate or innervation status of the supraspinatus. Fatty infiltration occurs independent of denervation of the supraspinatus.
Subject(s)
Motor Endplate/injuries , Motor Endplate/pathology , Peripheral Nerve Injuries/pathology , Rotator Cuff Injuries , Rotator Cuff/pathology , Tendon Injuries/pathology , Adipose Tissue/pathology , Animals , Disease Models, Animal , Muscle, Skeletal/pathology , Muscular Atrophy/pathology , Nerve Degeneration/pathology , Neuromuscular Junction/injuries , Neuromuscular Junction/pathology , Rabbits , Rotator Cuff/innervationABSTRACT
BACKGROUND: Approximately 25% of distal clavicle fractures are unstable. Unstable patterns have longer times to union and higher nonunion rates. Stable restoration of the distal clavicle is important in decreasing the nonunion rate in distal clavicle fractures. The purpose of this study was to biomechanically compare operative constructs for the treatment of unstable, comminuted distal-third clavicle fractures in a cadaveric model using a locking plate and coracoclavicular reconstruction. We hypothesized that the combination of coracoclavicular reconstruction and a distal clavicle locking plate is biomechanically superior to either construct used individually. MATERIALS AND METHODS: An unstable distal clavicle fracture was created in 21 thawed fresh-frozen cadaveric specimens. The 21 specimens were divided into 3 treatment groups of 7: distal-third locking plate, acromioclavicular (AC) TightRope (Arthrex, Naples, FL, USA), and distal-third locking plate and AC TightRope together. After fixation, each specimen was cyclically tested with recording of displacement to determine the stiffness and stability of each construct, followed by load-to-failure testing in tension and compression to determine the maximum load. RESULTS: The combined construct of the locking distal clavicle plate and coracoclavicular reconstruction resulted in increased stiffness, maximum resistance to compression, and decreased displacement compared with either construct alone. CONCLUSION: Greater fracture stability was achieved with the combination of the AC TightRope and locking clavicle plate construct than with either alone, suggesting a possibility for increased fracture-healing rates.
Subject(s)
Clavicle/injuries , Fractures, Comminuted/surgery , Biomechanical Phenomena , Bone Plates , Fracture Fixation, Internal , Fracture Healing , Fractures, Bone , HumansABSTRACT
BACKGROUND: The throwing motion results in unilateral increases in dominant arm external rotation (ER) range of motion (ROM). Trunk forward tilt at ball release is related to ball velocity. The relationship between lower quarter flexibility and dominant arm ROM is not known. HYPOTHESIS: There is a relationship between lower extremity flexibility and dominant arm ER ROM and total rotation ROM. STUDY DESIGN: Prospective cohort study. METHODS: Forty-two collegiate baseball pitchers were studied. Demographics, dominant arm, and bilateral glenohumeral ER and internal rotation (IR) ROM were measured. Lower quarter flexibility was assessed via sit-and-reach test. Total rotation motion (TRM) was calculated as ER + IR = TRM. Paired t tests examined differences between the dominant and nondominant arms for ER, IR, and TRM; Pearson product-moment correlation coefficients, shoulder ROM and lower extremity flexibility variables (α = 0.05). RESULTS: ER mean value was significantly greater, and IR mean value significantly less, in the dominant arm. TRM mean values were not significantly different bilaterally. Sit-and-reach results were strongly correlated with TRM and ER of the dominant arm. CONCLUSIONS: There was a significant shift in TRM toward ER in collegiate baseball players. Lower quarter flexibility was strongly correlated with dominant arm ER and total rotation ROM but not in the nondominant arm. CLINICAL RELEVANCE: The sit-and-reach test may be useful to identify a pitcher's potential to achieve an appropriate amount of trunk forward tilt. This may maximize the lag effect necessary to achieve maximum ER of the dominant arm and increased ball velocity.
ABSTRACT
We conducted a study to compare 3 methods of measuring knee range of motion: visual estimation by physicians, hand goniometry by physical therapists, and radiographic goniometry. We hypothesized that reliability would be high within and across all techniques. We found intrarater and interrater reliability to be satisfactory for visual estimation, hand goniometry, and radiographic goniometry. Interrater reliability across methods did not agree satisfactorily. Between-methods differences in estimating knee range of motion may result from variations in technique among physicians and physical therapists.
Subject(s)
Arthrometry, Articular/methods , Knee Joint/physiology , Range of Motion, Articular/physiology , Adult , Humans , Male , Observer Variation , Reproducibility of Results , Young AdultABSTRACT
Orthopedic joint procedures frequently require extensive dissection of skeletal muscles resulting in tissue injury, formation of scar tissue, pain, and potentially, functional impairment. The authors hypothesized that using a low-temperature ultrasonic cutting and coagulating device (Harmonic Blade, Ethicon Endo-Surgery, Cincinnati, OH) would result in reduction in tissue trauma in terms of reducing acute and chronic inflammation during healing. Bilateral longitudinal incisions were made into the tibialis cranialis muscles of rabbits with either a Harmonic Blade or a standard monopolar electrosurgical scalpel. At 3, 7, and 21 days postoperatively, necropsy and histological evaluations indicated a significant attenuation of acute inflammation (P = .011) for the Harmonic incisions compared with electrosurgery. No significant differences were observed for chronic inflammation, necrosis, or fibrosis. Use of a Harmonic scalpel during dissection of skeletal muscle in orthopedic surgery may result in reduced influx of neutrophils, reducing acute inflammation, and potentially aid in reducing postoperative pain and functional impairment.
Subject(s)
Muscle, Skeletal/pathology , Muscle, Skeletal/physiology , Orthopedic Procedures/instrumentation , Ultrasonic Therapy/instrumentation , Animals , Dissection/instrumentation , Female , Models, Animal , Rabbits , Wound HealingSubject(s)
Collateral Ligaments/surgery , Elbow Injuries , Joint Dislocations/surgery , Orthopedic Procedures/methods , Plastic Surgery Procedures/methods , Ulna , Chronic Disease , Collateral Ligaments/diagnostic imaging , Elbow Joint/diagnostic imaging , Elbow Joint/physiopathology , Female , Humans , Joint Dislocations/diagnostic imaging , Joint Dislocations/physiopathology , Middle Aged , Radiography , Range of Motion, Articular , Recovery of Function , Treatment OutcomeABSTRACT
This study compared the graft/femoral tunnel angle produced with the outside-in technique with the inside-out technique at 90 degrees and 120 degrees of flexion. Three femoral tunnels were marked with guidewires and measured radiographically in 8 fresh-frozen cadaveric knees using both techniques. Results were analyzed. The mean graft/femoral tunnel angle was 34.4 degrees +/- 14.4 degrees for the outside-in technique, 52.3 degrees +/- 14.1 degrees for the inside-out technique at 120 degrees of flexion, and 74.4 degrees +/- 11 degrees for the inside-out technique at 90 degrees of flexion. The angle was smaller for the outside-in technique versus the inside-out technique at both 120 degrees (P = .019) and 90 degrees of knee flexion (P < .001). The outside-in technique for femoral tunnel placement produces the lowest graft/femoral tunnel angle in cadavers. With the inside-out technique, 120 degrees of flexion produces smaller angles than does 90 degrees of flexion. The outside-in technique results in lower angles and perhaps lower graft failure rates. However, additional clinical studies are needed.
Subject(s)
Femur/surgery , Joint Instability/surgery , Plastic Surgery Procedures/methods , Posterior Cruciate Ligament/transplantation , Tibia/surgery , Adult , Aged , Algorithms , Arthroplasty, Replacement, Knee/methods , Arthroscopy/methods , Biomechanical Phenomena , Cadaver , Femur/diagnostic imaging , Humans , Knee Injuries/surgery , Middle Aged , Posterior Cruciate Ligament/diagnostic imaging , Posterior Cruciate Ligament/surgery , Radiography , Range of Motion, Articular , Reproducibility of Results , Tibia/diagnostic imagingABSTRACT
Femoral and tibial tunnel widening following ACL reconstruction using hamstring autograft has been described. Greater tunnel widening has been reported with suspensory fixation systems. We hypothesized that greater tunnel widening will be observed in patients whose hamstring autograft was fixated using a cortical, suspensory system, compared to double cross-pin fixation on the femur. We performed clinical and radiographic evaluation on 46 patients at minimum 2 years after primary ACL reconstruction. We measured subjective and objective outcomes including KT-1000 and AP, lateral radiographs. A musculoskeletal radiologist, independent of the surgical team, measured tunnel width, while correcting for magnification, at the widest point and at 1 cm away from tibial and femoral tunnel apertures. Patients in the suspensory graft fixation group exhibited significantly greater absolute change and greater percent change in femoral tunnel diameter compared to patients with double cross-pin fixation (PSubject(s)
Absorbable Implants/adverse effects
, Anterior Cruciate Ligament/surgery
, Arthroscopy/adverse effects
, Knee Joint/pathology
, Knee Joint/surgery
, Suture Anchors/adverse effects
, Adult
, Anterior Cruciate Ligament Injuries
, Arthroscopy/methods
, Humans
, Middle Aged
, Osteolysis
, Retrospective Studies
, Young Adult
ABSTRACT
PURPOSE: The purpose of this study is to evaluate the changes in fatty infiltration of the rotator cuff after it is repaired. METHODS: The supraspinatus muscle was unilaterally detached from the greater tuberosity in 15 New Zealand white rabbits. Six weeks after muscle detachment, 5 rabbits were killed to halt the process of fatty infiltration and 10 rabbits underwent primary repair of the rotator cuff. Six months after repair, the remaining 10 rabbits were killed, and the muscle specimens were examined microscopically to evaluate the muscle with respect to fatty infiltration. RESULTS: Fatty infiltration was evident 6 weeks after detachment of the supraspinatus tendon (P = .0012, analysis of variance). This infiltration was greatest at the musculotendinous junction (P = .0005) and decreased toward the muscle origin (P = .29). Six months after repair of the supraspinatus, there was no progression of fatty infiltration in the repaired muscle as compared with the controls (P = .3). CONCLUSIONS: Fatty infiltration of the rotator cuff in this animal model occurs as early as 6 weeks after a rotator cuff tear. After repair of the rotator cuff, the process of fatty infiltration does not progress any further. The changes that take place in this rabbit model in the first 6 weeks after a rotator cuff tear appear to be irreversible even with successful rotator cuff repair. CLINICAL RELEVANCE: The presence of fatty infiltration of a torn rotator cuff does not preclude a successful repair. The repair can prevent further progression and atrophy of the rotator cuff, but the changes that appear in the muscle as early as 6 weeks after a rotator cuff tear appear to be irreversible.
Subject(s)
Adipose Tissue/pathology , Lacerations/surgery , Orthopedic Procedures , Rotator Cuff/pathology , Rotator Cuff/surgery , Animals , Lacerations/pathology , Postoperative Period , Rabbits , Rotator Cuff Injuries , Time FactorsABSTRACT
Joint infection after anterior cruciate ligament (ACL) reconstruction is a rare but important clinical issue that must be resolved quickly to prevent secondary joint damage and preserve the graft. After careful analysis, we observed 3 infection cases within a 12-month period after ACL reconstruction, which represented an abnormally elevated risk. All reconstructions were performed by the same surgeon and used hamstring tendon allograft. For each surgery, the Target Tendon Harvester (DePuy Mitek, Raynham, MA) was used to harvest hamstring tendons. Through our review, we learned that this instrument was sterilized while assembled. It is our belief that ineffective sterilization of this hamstring graft harvester served as the origin for these infections. We have determined that appropriate sterilization technique involves disassembly of this particular hamstring tendon harvester before sterilization because of the tube-within-a-tube configuration. We have since continued to use the Target Tendon Harvester, disassembling it before sterilization. There have been no infections in the ensuing 12 months during which the surgeon performed over 40 primary ACL reconstructions via hamstring autograft. The information from this report is intended to provide arthroscopists with information about potential sources of infection after ACL reconstruction surgery.
Subject(s)
Anterior Cruciate Ligament/surgery , Bacterial Infections/etiology , Joint Diseases/microbiology , Knee Joint/microbiology , Plastic Surgery Procedures/methods , Tendons/surgery , Tissue and Organ Harvesting/adverse effects , Bone-Patellar Tendon-Bone Grafting , Equipment Contamination , Humans , Retrospective Studies , Sterilization/methods , Tissue and Organ Harvesting/instrumentationABSTRACT
Opening wedge high tibial osteotomies are performed for degenerative changes and varus. Opening wedge osteotomies can change proximal tibial slope in the sagittal plane, possibly imparting stability in the ACL-deficient knee. The aim of this study was to assess the effect of plate position and size on change in tibial slope. Eight cadaveric knees underwent opening wedge high tibial osteotomy with Puddu plates of each different size. Plates were placed anterior, central, and posterior for each size used. Lateral radiographs were obtained. Tibial slope was measured and compared with baseline slope. Tibial slope was affected by plate position (P < 0.05) and size (P < 0.001). Smaller, posterior plates had less effect on tibial slope. However, anterior and central plates increased tibial slope over all plate sizes (P < 0.05). This study found that tibial slope increases with opening wedge high tibial osteotomy. Larger corrections and anterior placement of the plate are associated with larger increases in slope.
Subject(s)
Osteotomy/instrumentation , Osteotomy/methods , Tibia/surgery , Adult , Aged , Bone Plates , Humans , Middle AgedABSTRACT
PURPOSE: The purpose of this investigation is to document quantitatively and qualitatively the changes that occur over time in the rotator cuff muscle after surgical detachment, simulating a chronic, unrepaired rotator cuff tear. METHODS: The supraspinatus muscle was unilaterally detached from the greater tuberosity in 20 New Zealand white rabbits. All tendons were tagged and retracted from the insertion on the greater tuberosity. Five rabbits were killed at each designated time interval of 6 weeks, 3 months, 6 months, or 1 year after surgery. All animals underwent whole-body perfusion at the time of death for tissue preservation. Gross and histologic evaluations were performed to quantify the progression of fatty infiltration over time. RESULTS: Loss of muscle and fatty infiltration were evident 6 weeks after detachment of the supraspinatus tendon. The fatty infiltration increased over time from 6 weeks to 1 year (P = .002, analysis of variance). The fatty infiltration was most pronounced near the supraspinatus insertion, and it progressed from the musculotendinous junction toward the muscle origin (Pearson correlation, r = -0.51; P < .0001). CONCLUSIONS: In this rabbit model of a surgically created rotator cuff tear, fatty infiltration is a progressive, infiltrative process that increases over time in the unrepaired rotator cuff. In addition, the muscle atrophy and fatty infiltration seen in rotator cuff tears progress from the musculotendinous junction toward the muscle origin. CLINICAL RELEVANCE: This animal model of a chronic rotator cuff tear shows that fatty infiltration of the supraspinatus muscle appears as early as 6 weeks and worsens over time in the unrepaired rotator cuff. This may have implications on both the timing and management of rotator cuff tears.
Subject(s)
Adipose Tissue/pathology , Rotator Cuff Injuries , Rotator Cuff/pathology , Animals , Disease Models, Animal , Female , Muscular Atrophy/pathology , Rabbits , Reference Values , Rotator Cuff/physiology , Rupture/pathologyABSTRACT
BACKGROUND: The ability to accurately predict the diameter of autograft hamstring tendons has implications for graft choice and fixation devices used in anterior cruciate ligament (ACL) reconstruction. PURPOSE: To determine whether simple anthropometric measurements such as height, mass, body mass index (BMI), age, and gender can be used to accurately predict the diameter of hamstring tendons for ACL reconstruction surgery. STUDY DESIGN: Cohort study (prevalence); Level of evidence, 2. METHODS: The authors conducted medical record reviews and telephone interviews of 106 consecutive patients with ACL reconstruction using quadrupled semitendinosus-gracilis autograft from 2004 to 2006. Data included anthropometric measurements (height, mass, gender, and age at the time of surgery). Hamstring diameter was obtained using cylindrical sizers in 0.5-mm increments and recorded in the patient's surgical record. Correlation coefficients (Pearson r) and stepwise, multiple linear regression were used to determine the relationship between the outcome variable (hamstring graft diameter) and the predictor variables (age, gender, height, mass, and BMI). Independent sample t tests were used to compare hamstring graft diameter between genders. RESULTS: Hamstring graft diameter was related to height (r = .36, P < .001), mass (r = .25, P = .005), age (r = -.16, P = .05), and gender (r = -.24, P = .006) but was not related to BMI (P > .05). Height was a statistically significant prediction variable (R(2) = .13, P < .001). From the current data, a regression equation was calculated that suggested that a patient <147 cm (58 in) tall is likely to have a quadrupled hamstring graft diameter <7 mm in diameter (graft size = 2.4 + 0.03 x height in cm). Women had significantly smaller hamstring graft diameters (7.5 +/- 0.7 mm) than did men (7.9 +/- 0.9 mm, P = .01). CONCLUSIONS: Of the parameters studied, height was the best predictor of hamstring tendon diameter, particularly in women.