Faculty Bibliography

PURPOSE: Surgeons have noticed an increased incidence of finger lacerations associated with arthroscopic knot tying with solid-core suture material. This study examines glove perforations and finger lacerations during arthroscopic shoulder surgery. METHODS: We collected 400 surgical gloves from 50 consecutive arthroscopic shoulder repair procedures using No. 2 solid-core sutures. Two surgeons using double gloves were involved in every case, with one being responsible for tying all knots. Powder-free latex gloves were worn in all cases. Knots consisted of a sliding stitch of the surgeon's preference followed by 3 half-hitches via a knot-pusher instrument. All gloves were inspected grossly and then tested for tears with an electroconductivity meter. RESULTS: The knot-tying surgeon had significantly more glove tears than the control (P < .01). Tears were localized to the radial side of the index finger of the glove at the distal interphalangeal joint in all cases. Of the tying surgeon's gloves, 68 (34%) were found to have tears. These included 17 inner gloves (17%) and 51 outer gloves (51%). If an inner glove was torn, the corresponding outer glove was torn in all cases. A mean of 3.96 knots were tied in each case. There was a significantly higher incidence of inner glove tears when more than 3 knots were tied (P < .03). There was no significant difference in glove tears between suture types. Finger lacerations did occur in the absence of glove tears. However, in the presence of an inner glove tear, there was a statistically significant association with a finger laceration at the corresponding level (P < .03). CONCLUSIONS: Intraoperative glove tears and subsequent finger lacerations occur with a high frequency when arthroscopic knots are tied with solid-core suture material. Risk can potentially be minimized by frequent glove changes or use of more durable, less penetrable gloves. CLINICAL RELEVANCE: This study addresses surgeon and patient safety during arthroscopic shoulder surgery

BACKGROUND: Strain injury to the adductor longus muscle is a common cause of groin pain in athletes and generally occurs in the proximal portion of the muscle, near its origin from the anterior aspect of the pubis. The composition and cross-sectional anatomy of this muscle's origin has not been previously described. HYPOTHESIS: We hypothesize that the adductor longus muscle origin is composed mainly of muscle fibers and that the tendon composes only a small part of the cross section at the origin of the muscle. STUDY DESIGN: Descriptive laboratory study. METHODS: We harvested 42 adductor longus muscles from 28 cadavers and measured the cross-sectional dimensions of the tendon with microcalipers. Next, we determined the relative contributions of the tendon and muscle fibers to the cross-sectional anatomy of the muscle using optical scanning. These 2 sets of measurements were obtained at 3 locations: at the muscle origin and 1.0 and 2.0 cm distal to the origin. RESULTS: The average length and width of the tendon was 11.6 and 3.7 mm, respectively, at the origin. The average cross-sectional areas of the tendon were 49.3, 27.9, and 25.7 mm(2) at points 0.0, 1.0, and 2.0 cm from its origin, respectively. The origin of the adductor longus muscle was composed of 37.9% tendon and 62.1% muscle tissue. At 1.0 cm from the origin, the percentage of tendon decreased to 34%. At 2.0 cm from the origin, the tendon composed 26.7% of the cross section. CONCLUSION: The cross-sectional area of the tendon of the adductor longus muscle is relatively small. The muscle origin is composed predominantly of direct attachment of muscle fibers. CLINICAL RELEVANCE: Knowledge of the cross-sectional anatomy of the adductor longus muscle at its origin may help clinicians better understand the complex nature of injuries in this area

OBJECTIVE: To compare the fixation stability of intramedullary nails to that of locked plates for the treatment of distal metaphyseal tibia and fibula fractures. METHODS: A simulated, distal metaphyseal tibia fracture was created in 8 pairs of cadaveric tibia-fibula specimens. One of each pair was treated using an intramedullary nail (Trigen IM Nail System; SN Richards, Memphis, TN) and the other with a locked plate (Peri-Loc Periarticular Locked Plating System; SN Richards). Each specimen was vertically loaded to 250 N in central, anterior, posterior, medial, and lateral locations; loaded to 250 N in cantilever bending in anterior to posterior and posterior to anterior directions; and loaded to 250 N mm in torsion. Load-displacement curves were generated to determine the construct stiffness for each loading scenario, with comparisons made between the 2 treatment groups. Each specimen was then cyclically loaded with 750 N vertical loads applied for 10, 100, 1000, and 10,000 cycles. Measurements of fracture displacements were made and compared between treatment groups. A fibular osteotomy was then created in each specimen at the same level as the tibia fracture to simulate a same-level tibia-fibular fracture. Torsional stiffness assessment and cyclic vertical loading for 10, 100, 1000, and 10,000 cycles were repeated and fracture displacement measurements were again obtained. RESULTS: The locked plate construct was stiffer than the intramedullary nail construct for central, anterior, and posterior loading scenarios (P < 0.005, P < 0.03, and P < 0.02, respectively). The intramedullary nail construct was stiffer than the locked plate construct for both anterior to posterior and posterior to anterior cantilever bending (P < 0.03 and P < 0.02, respectively). No statistically significant difference in stiffness was noted between treatment groups for medial and lateral vertical loading or for torsional loading (P = 0.09, P = 0.32, and P = 0.84, respectively). There was no significant difference between treatment groups with respect to fracture displacement after cyclic vertical loading. After creation of the fibular osteotomy fracture, construct displacements after 1000 and 10,000 cycles significantly increased and torsional stiffness significantly decreased for both treatment groups. The locked plate constructs had significantly less displacement after cyclic loading of 1000 and 10,000 than the locked nail constructs (P < 0.001 and P < 0.0001, respectively). Locked plate constructs were stiffer in torsion after osteotomy than the intramedullary nail constructs (P < 0.05). CONCLUSION: This study demonstrated that, in the treatment of distal metaphyseal tibia fractures, locked plates provided more stable fixation than intramedullary nails in vertical loading but were less effective in cantilever bending. An intact fibula in the presence of a distal tibia fracture improved the fracture fixation stability for both treatment methods. In fracture patterns in which the fibula cannot be effectively stabilized, locked plates offer improved mechanical stability when compared with locked intramedullary nails

OBJECTIVE: To determine the effect of reinforced calcium phosphate cement augmentation of the femoral neck defect created after dynamic hip screw removal in a cadaveric model. METHODS: The lag screws of dynamic hip screw implants were inserted and subsequently removed in 8 matched pairs of cadaveric, osteoporotic femurs to create a femoral neck defect. One of each pair had the defect augmented with osteoconductive calcium phosphate cement reinforced with poly(lactide-coglycolide) fibers (Norian Reinforced, Synthes, West Chester, PA), and the other defect was not augmented. Each specimen was first cyclically loaded with 750 N vertical loads applied for 1000 cycles to simulate early weightbearing, and then loaded to failure. RESULTS: Calcium phosphate cement augmentation of the lag screw defect significantly increased the mean femoral neck failure strength (4819 N) compared to specimens in which the defect was left untreated (3995 N) (P < 0.004). The mechanism of failure for each specimen was a fracture through the femoral neck. Regression analysis demonstrated that load to failure was directly related to the bone mineral density at Ward's triangle, and the impact of cement augmentation on failure strength was greatest for specimens with the lowest bone mineral density (correlation coefficient: -0.82, P < 0.0001). CONCLUSION: This study demonstrates that augmentation of the bony defect created by dynamic hip screw removal with reinforced calcium phosphate cement significantly improved the failure strength of the bone. Cement augmentation after hardware removal may decrease the risk of refracture and allow early weightbearing, especially in elderly patients with osteoporotic bone.

The purpose of this report was to evaluate patient outcomes after treatment of acute midshaft clavicle fractures with an intramedullary Hagie pin, including clinical results and the incidence of postoperative complications. Between 1993 and 2003, 16 patients who underwent intramedullary Hagie pin fixation of a midshaft clavicle fracture were identified. The medical records of each patient were reviewed to ascertain the mechanism of injury, indication for surgical intervention, and treatment course. Clinical outcomes were evaluated with respect to time to fracture union, postoperative shoulder range of motion, and symptoms related to the fracture site and ipsilateral shoulder. The inpatient postoperative course and outpatient follow-up visits were assessed in an effort to document the incidence of postoperative complications. The most common mechanism of injury was participation in athletic activity. Operative indications included significant deformity, polytrauma, and neurovascular compromise. The mean time from injury to operative fracture stabilization was 15.8 days. No intraoperative complications occurred. All 16 patients (100%) were available for follow-up to fracture union, which occurred in all cases at a mean of 12.4 weeks. Of the 16 patients, 14 were available for further follow-up, and at a mean follow-up of 9 months, 85.7% had regained near-full to full range of shoulder motion and 93% had no symptoms related to the fracture site or ipsilateral shoulder. Postoperative complications occurred in 8 patients (50%), including 3 cases of skin breakdown related to hardware prominence, 2 cases of hardware breakage, 2 cases of decreased sensation in the region of the surgical incision, and 1 case of persistent pain over the operative site. When indicated, the use of intramedullary devices for the stabilization of clavicle fractures offers theoretic advantages over traditional plate and screw fixation. In this case series, intramedullary Hagie pin fixation resulted in fracture union in 100% of cases, with a high percentage of patients regaining full range of shoulder motion and resolution of symptoms. However, there was a 50% incidence of postoperative complications associated with this treatment method. We believe that the complication rate associated with the use of the Hagie pin should preclude the use of this particular implant.

Purpose: There are many options for arthroscopic knots including the type of knot and suture material used. The current investigation evaluated knot properties using 3 high-strength suture materials tied in 5 common arthroscopic knot configurations. Methods: Four arthroscopic sliding knots including the Roeder, Weston, SMC, and Tennessee Slider and an arthroscopic nonsliding Surgeon's knot were evaluated. Each knot was tied with each of 3 No. 2 polyblended suture types (Fiberwire [Arthrex, Naples, FL], Ultrabraid [Smith & Nephew, Andover, MA], and Orthocord [Mitek, Raynham, MA]). Each configuration was tied 8 times, for a total of 120 samples. Loop security and knot security were then evaluated by using a previously described protocol comparing the different knot types and suture material. Results: With respect to loop security, Orthocord performed better than the other tested suture materials, producing on average smaller knot loops. For the nonsliding Surgeon's knot, there was no difference in loop security observed between suture types. For the Roeder knot, Fiberwire had superior knot security compared with Ultrabraid and Orthocord (P < .001). For the Weston knot, Ultrabraid showed superior knot security compared with Orthocord (P < .02). Knot security for the Tenessee slider knot was better for both Fiberwire and Ultrabraid compared with Orthocord (P < .001, respectively). Similar results were seen with the SMC knot, with Fiberwire and Ultrabraid outperforming Orthocord (P < .001, respectively). The nonsliding Surgeon's knot had significantly lower mean loads to failure compared with arthroscopic sliding knots for each tested suture material (P < .02 for all comparisons). Conclusions: Loop security and knot security varied depending on the type of knot tied and suture material used. Arthroscopic sliding knots performed better than the nonsliding Surgeon's knot. Clinical Relevance: Surgeons should try to use sliding knots instead of Surgeon's knots when using polyblend suture material. Differences between the brands in this suture category will change the characteristics of the knots thrown and may ultimately affect tissue fixation

OBJECTIVE: To determine whether positioning of the tibia affects the degree of tibial external rotation seen during a dial test in the posterior cruciate ligament (PCL)-posterolateral corner (PLC)-deficient knee. DESIGN: Laboratory investigation. SETTING: Biomechanics laboratory. Hypothesis: An anterior force applied to the tibia in the combined PCL-PLC-deficient knee will yield increased tibial external rotation during a dial test. METHODS: The degree of tibial external rotation was measured with 5 Nm of external rotation torque applied to the tibia at both 30 degrees and 90 degrees of knee flexion. Before the torque was applied, an anterior force, a posterior force, or neutral (normal, reduced control) force was applied to the tibia. External rotation measurements were repeated after sequential sectioning of the PCL, the posterolateral structures and the fibular collateral ligament (FCL). RESULTS: Baseline testing of the intact specimens demonstrated a mean external rotation of 18.6 degrees with the knee flexed to 30 degrees (range 16.1-21.0 degrees ), and a mean external rotation of 17.3 degrees with the knee flexed to 90 degrees (range 13.8-20.0 degrees ). Sequential sectioning of the PCL, popliteus and popliteofibular ligament, and the FCL led to a significant increase in tibial external rotation compared with the intact knee for all testing scenarios. After sectioning of the popliteus and popliteofibular ligament, the application of an anterior force during testing led to a mean tibial external rotation that was 5 degrees greater than during testing in the neutral position and 7.5 degrees greater than during testing with a posterior force. In the PCL, popliteus/popliteofibular ligament and FCL-deficient knee, external rotation was 9 degrees and 12 degrees greater with the application of an anterior force during testing compared with neutral positioning and the application of a posterior force, respectively. CONCLUSION: An anterior force applied to the tibia during the dial test in a combined PCL-PLC-injured knee increased the overall amount of observed tibial external rotation during the dial test. The anterior force reduced the posterior tibial subluxation associated with PCL injury, which is analogous to what is observed when the dial test is performed with the patient in the prone position. Reducing the tibia with either an anterior force when the patient is supine or performing the dial test with the patient in the prone position increases the ability of an examiner to detect a concomitant PLC injury in the setting of a PCL-deficient knee

Many orthopaedic surgeons believe that obese patients have a higher rate of peri-operative complications and a worse functional outcome than non-obese patients. There is, however, inconsistency in the literature supporting this notion. This study was performed to evaluate the effect of body mass index (BMI) on injury characteristics, the incidence of complications, and the functional outcome after the operative management of unstable ankle fractures. We retrospectively reviewed 279 patients (99 obese (BMI > or = 30) and 180 non-obese (BMI < 30) patients who underwent surgical fixation of an unstable fracture of the ankle. We found that obese patients had a higher number of medical co-morbidities, and more Orthopaedic Trauma Association type B and C fracture types than non-obese patients. At two years from the time of injury, however, the presence of obesity did not affect the incidence of complications, the time to fracture union or the level of function. These findings suggest that obese patients should be treated in line with standard procedures, keeping in mind any known associated medical co-morbidities

Among 25 patients of mean age 91.5 years (range, 90-96 years) who received a total hip or knee arthroplasty at the authors' institution, 8% experienced surgical complications, 56% experienced at least 1 medical complication, and 80% received perioperative blood transfusions. At a mean follow-up of 4.1 years, patients were experiencing pain reduction and somewhat higher functional capacity and had slightly better survival characteristics than age-matched controls. Total hip and knee arthroplasty patients in this cohort should be told that they have a higher likelihood of experiencing perioperative medical complications and of receiving a blood transfusion than younger individuals; at the same time, they can expect pain relief as well as equal or better survival than their age-matched peers

The development of cerclage systems for fixation of greater trochanteric osteotomies has progressed from monofilament wires to multifilament cables to cable grip and cable plate systems. Cerclage wires and cables have various clinical indications, including fixation for fractures and for trochanteric osteotomy in hip arthroplasty. To achieve stable fixation and eventual union of the trochanteric osteotomy, the implant must counteract the destabilizing forces associated with pull of the peritrochanteric musculature. The material properties of cables and cable grip systems are superior to those of monofilament wires; however, potential complications with the use of cables include debris generation and third-body polyethylene wear. Nevertheless, the cable grip system provides the strongest fixation and results in lower rates of nonunion and trochanteric migration. Cable plate constructs show promise but require further clinical studies to validate their efficacy and safety