Background: Arthroscopic repair of anterior dislocation of the shoulder can fail. We hypothesized that patients who are at higher risk for redislocation following repair could be recognized preoperatively on the basis of their clinical history. The purpose of the present study was to identify the risk factors for recurrence in a community-based population of patients with traumatic unidirectional instability that was treated with a single arthroscopic technique.

Methods: From January 2000 to December 2003, 625 patients with anterior unidirectional instability were managed with an arthroscopic Bankart technique, and 385 met the criteria for inclusion in the study. Demographic data were collected, and clinical follow-up was performed at three, six, twelve, twenty-four, and thirty-six months.

Results: At thirty-six months, thirty-one patients (8.1%) had experienced a redislocation; the rate was 13.3% among patients who were twenty-two years of age and younger and 6.3% among older patients. Age at the time of the first dislocation, male sex, and the time from the first dislocation until surgery were significant risk factors for recurrence (p < 0.05 for all).

Conclusions: Patients who are more likely to have a redislocation following arthroscopic repair of an anterior shoulder dislocation can be identified preoperatively on the basis of sex, age, and the time from the first dislocation to surgery.

Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

Background: Despite its technical complexity, arthroscopic tibial inlay reconstruction of the posterior cruciate ligament has biomechanical advantages over transtibial procedures. The purpose of this study was to compare the clinical results of arthroscopic tibial inlay single-bundle and double-bundle techniques with those of the conventional transtibial single-bundle technique.

Methods: We evaluated twenty-nine patients treated with primary posterior cruciate ligament reconstruction and followed for longer than two years. Eight patients were treated with a transtibial single-bundle procedure; eleven, with an arthroscopic inlay single-bundle procedure; and ten, with an arthroscopic inlay double-bundle procedure. An Achilles tendon allograft was used in all cases. Each patient was evaluated on the basis of the Lysholm knee score, the mean side-to-side difference in tibial translation as measured on Telos stress radiographs, and the side-to-side difference in the range of motion of the knee.

Results: The mean side-to-side difference (and standard deviation) in posterior tibial translation differed significantly between the arthroscopic tibial inlay double-bundle group (3.6 ± 1.43 mm) and the transtibial single-bundle group (5.6 ± 2.00 mm) (p = 0.023), although there was no significant difference between the arthroscopic inlay single-bundle group (4.7 ± 1.62 mm) and the transtibial group (p = 0.374). The mean range of motion and Lysholm scores were similar among the three groups.

Conclusions: Despite its technical difficulty, the arthroscopic tibial inlay double-bundle technique is our preferred method of reconstruction of the posterior cruciate ligament because it stabilizes posterior tibial translation better than do the other two methods.

Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Background: Multimodal pain-control protocols that include periarticular injections have been reported to decrease pain and improve early outcomes following total knee arthroplasty. While injections containing a corticosteroid have been demonstrated to be safe and effective, we are not aware of any randomized trials in which the specific effect of the corticosteroid on early postoperative outcomes has been evaluated. The purpose of this double-blind study was to compare the clinical efficacy of periarticular injections consisting of bupivacaine, morphine, epinephrine, clonidine, and cefuroxime as well as a corticosteroid (methylprednisolone acetate) with the efficacy of periarticular injections consisting of the same agents but without the inclusion of a corticosteroid.

Methods: Seventy-six patients were randomized to either the no-steroid group (thirty-seven patients) or the steroid group (thirty-nine patients). Pain and narcotic consumption during the inpatient stay and the length of the hospital stay were recorded. Knee Society scores, the range of motion, and the occurrence of any complications were recorded preoperatively and at six and twelve weeks after the surgery.

Results: The hospital stay was significantly shorter for patients in the steroid group (2.6 days compared with 3.5 days in the no-steroid group; p = 0.01). No significant group differences in terms of pain, narcotic consumption, outcome scores, or motion were identified. There were three complications in the steroid group: two patients required a manipulation under anesthesia, and the knee joint became infected in another patient, leading to numerous complications and ultimately death.

Conclusions: The periarticular injection of a corticosteroid may reduce the length of the hospital stay following total knee arthroplasty, but it does not appear to improve pain relief, motion, or function in the early postoperative period. While we cannot definitively state that the corticosteroid was a causative factor in the development of the infection at the site of the prosthetic joint, we cannot rule it out either, which raises concern regarding the role of corticosteroids in perioperative pain management following total knee arthroplasty.

Level of Evidence: Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

Background: While alendronate therapy has been shown to decrease the risk of vertebral and femoral neck fractures in postmenopausal osteoporotic patients, recent reports have associated long-term alendronate therapy with unilateral low-energy subtrochanteric and diaphyseal femoral fractures in a small number of patients. To our knowledge, there has been only one report of sequential bilateral femoral fractures in patients on long-term bisphosphonate therapy.

Methods: We retrospectively reviewed the case log of the senior author over the last four years to identify patients who presented with a subtrochanteric or diaphyseal femoral fracture after a low-energy mechanism of injury (a fall from standing height or less) and who had been taking alendronate for more than five years. Radiographs were reviewed, and the fracture patterns were recorded. Serum calcium levels were recorded when available.

Results: Seven patients who sustained low-energy bilateral subtrochanteric or diaphyseal femoral fractures while on long-term alendronate therapy were identified. One patient presented with simultaneous bilateral diaphyseal fractures, two patients had sequential subtrochanteric fractures, and four patients had impending contralateral subtrochanteric stress fractures noted at the time of the initial fracture. Of the latter four, one patient had a fracture through the stress site and the other three patients had prophylactic stabilization of the site with internal fixation. No patient had discontinued alendronate therapy prior to the second fracture. All patients were women with an average age of sixty-one years, and they had been on alendronate therapy for an average of 8.6 years. All fractures were treated with reamed intramedullary nailing and went on to union at an average of four months.

Conclusions: In patients on long-term alendronate therapy who present with a subtrochanteric or diaphyseal femoral fracture, we recommend radiographs of the contralateral femur and consideration of discontinuing alendronate in consultation with an endocrinologist. If a contralateral stress fracture is found, prophylactic fixation should be considered.

Level of Evidence: Prognostic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Patellar resurfacing in total knee arthroplasty remains controversial. This study compared the long-term clinical outcomes of total knee arthroplasties performed with and without the patella resurfaced and is an update of a previous report. Eighty-six patients (118 knees) underwent primary total knee replacement and were randomized into two groups: those treated with and those treated without resurfacing of the patella. Outcomes included the scores according to the Knee Society clinical rating system, the scores according to a forty-one-question patellofemoral-specific patient questionnaire, patient satisfaction, global and anterior knee pain scores, radiographic findings, and complications and revisions. Fifty-seven patients (seventy-eight knees) were followed for a minimum of ten years. No significant differences were identified between the two groups in terms of the range of motion, Knee Society scores, satisfaction, global knee pain, or anterior knee pain. The overall revision rates in the original series of 118 knees were 12% in the nonresurfacing group and 9% in the resurfacing group. Seven patients (12%) in the nonresurfacing group and two patients (3%) in the resurfacing group underwent revision for a reason related to a patellofemoral problem. On the basis of these findings, we concluded that, with the type of total knee arthroplasty used in our patients, similar results may be achieved with and without patellar resurfacing.

Level of Evidence: Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.

Background: The increased risk for venous thromboembolic events following spinal trauma is well established. The purpose of the present study was to examine the literature in order to determine the optimum thromboprophylaxis regimen for patients with acute spinal injuries with or without spinal cord injury.

Methods: EMBASE, MEDLINE, and Cochrane databases were searched from the earliest available date to April 2008 for clinical trials comparing different methods of thromboprophylaxis in adult patients following acute spinal injuries (with or without spinal cord injury). Outcome measures included the prevalences of deep-vein thrombosis and pulmonary embolism and treatment-related adverse events.

Results: The search yielded 489 studies, but only twenty-one of them fulfilled the inclusion criteria. The prevalence of deep-vein thrombosis was significantly lower in patients without spinal cord injury as compared with patients with spinal cord injury (odds ratio = 6.0; 95% confidence interval = 2.9 to 12.7). Patients with an acute spinal cord injury who were receiving oral anticoagulants had significantly fewer episodes of pulmonary embolism (odds ratio = 0.1; 95% confidence interval = 0.01 to 0.63) than those who were not receiving oral anticoagulants (either untreated controls or patients managed with low-molecular-weight heparin). The start of thromboprophylaxis within the first two weeks after the injury resulted in significantly fewer deep-vein-thrombosis events than delayed initiation did (odds ratio = 0.2; 95% confidence interval = 0.1 to 0.4). With regard to heparin-based pharmacoprophylaxis in patients with spinal trauma, low-molecular-weight heparin significantly reduced the rates of deep-vein thrombosis and bleeding episodes in comparison with the findings in patients who received unfractionated heparin, with odds ratios of 2.6 (95% confidence interval = 1.2 to 5.6) and 7.5 (95% confidence interval = 1.0 to 58.4) for deep-vein thrombosis and bleeding, respectively.

Conclusions: The prevalence of deep-vein thrombosis following a spine injury is higher among patients who have a spinal cord injury than among those who do not have a spinal cord injury. Therefore, thromboprophylaxis in these patients should start as early as possible once it is deemed safe in terms of potential bleeding complications. Within this population, low-molecular-weight heparin is more effective for the prevention of deep-vein thrombosis, with fewer bleeding complications, than unfractionated heparin is. The use of vitamin K antagonists appeared to be effective for the prevention of pulmonary embolism.

Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Background: Wrong-site surgery remains a common problem as voluntary preoperative skin-marking protocols have met only limited success. The purpose of the present study was to investigate orthopaedic surgeons with regard to their site-signing practices and "time out" procedural compliance for emergent and nonemergent surgical cases in a single health-care region before and after the institution of the "time out" protocol of the Joint Commission on Accreditation of Healthcare Organizations.

Methods: In the first study, performed in 2006, the presence of the initials of either the surgeon or the surgical resident in the draped surgical field was documented at the time of forty-eight procedures over a three-month period. In a second study, performed a year later, 231 randomly selected procedures were similarly evaluated, as was the performance of the newly adopted "time out" process.

Results: In the first study, after surgical field draping, the surgeon's initials were visible in 67% of emergent cases and 90% of elective cases. In the second study, the surgeon's initials were visible in 61% of emergent cases and 83% of elective cases. The "time out" was performed prior to the skin incision in 70% of the cases, was performed after the incision in 19%, and was not performed at all in 11%.

Conclusions: Orthopaedic surgeons should recognize the value of preoperative skin signing for all procedures and the additional value of the "time out" protocol. We recommend that surgeons strive for 100% compliance with both strategies.

Background: High tibial osteotomy has been recognized as a beneficial treatment for osteoarthritis of the medial compartment of the knee. The purpose of this prospective study was to assess the short-term results of opening-wedge high tibial osteotomies with locked plate fixation.

Methods: From September 2002 to November 2005, fifty-one consecutive medial opening-wedge high tibial osteotomies were performed. The mean age of the patients at the time of the index operation was forty-nine years. The preoperative and postoperative factors analyzed included the grade of arthritis of the tibiofemoral compartment (the Ahlbäck radiographic grade), the anatomic tibiofemoral angle, patellar height, the Hospital for Special Surgery rating system score, and the Lysholm and Gillquist knee score.

Results: Postoperatively, one superficial wound infection occurred. Fifty of the fifty-one osteotomies healed after an average period of 12.9 weeks (range, eight to sixteen weeks) without bone grafts. A nonunion developed in a sixty-two-year-old patient who was a cigarette smoker. The average postoperative tibiofemoral angle was 9° of valgus. Forty-nine patients were followed for a mean of fifty-two months. The average score on the Hospital for Special Surgery rating system was 86 points at the time of the most recent follow-up. The rating was excellent in twenty-eight patients (57%), good in twelve (24%), fair in four (8%), and poor in five (10%). The average score on the Lysholm and Gillquist knee-scoring scale was 83 points. According to these scores, the outcome was excellent in nine patients (18%), good in thirty-one (63%), fair in three (6%), and poor in six (12%). Four knees failed after an average of thirty-six months.

Conclusions: Our results suggest that an opening-wedge high tibial osteotomy with locked plate fixation allows a correct valgus angle to be achieved with good short-term results.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Background: The authors of several studies have recommended extracorporeal shock-wave therapy as an alternative to surgical treatment for long-bone nonunions. This study was performed to compare the results of extracorporeal shock-wave therapy produced by two different devices with those of surgical treatment in the management of long-bone nonunions.

Methods: One hundred and twenty-six patients with a long-bone nonunion were randomly assigned to receive either extracorporeal shock-wave therapy (Groups 1 and 2) or surgical treatment (Group 3). The patients in the shock-wave groups received four treatments with 4000 impulses of shock waves with an energy flux density of 0.40 mJ/mm² (Group 1) or 0.70 mJ/mm² (Group 2). The patients in the three groups had similar demographic characteristics, durations of nonunion, and durations of follow-up. Radiographic results (the primary outcome) and clinical results (the secondary outcomes) were determined before and three, six, twelve, and twenty-four months after treatment.

Results: The radiographic findings did not differ among the three groups of patients. At six months, 70% of the nonunions in Group 1, 71% of the nonunions in Group 2, and 73% of the nonunions in Group 3 had healed. Three and six months after treatment, the clinical outcomes in the two shock-wave groups were significantly better than those in the surgical group (p < 0.001). However, at both twelve and twenty-four months after treatment, there were no differences among the three groups, with the exception of the DASH score, which differed significantly between Groups 1 and 3 (p = 0.038) and between Groups 2 and 3 (p = 0.021) at twelve months.

Conclusions: Extracorporeal shock-wave therapy is as effective as surgery in stimulating union of long-bone hypertrophic nonunions and yields better short-term clinical outcomes.

Level of Evidence: Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

Background: The intraoperative estimation of the anteversion of the femoral component of a total hip arthroplasty is generally made by the surgeon's visual assessment of the stem position relative to the condylar plane of the femur. Although the generally accepted range of intended anteversion is between 10° and 20°, we suspected that achieving this range of anteversion consistently during cementless implantation of the femoral component was more difficult than previously thought.

Methods: We prospectively evaluated the accuracy of femoral component anteversion in 109 consecutive total hip arthroplasties (ninety-nine patients), in which we implanted the femoral component without cement. In all hips, we measured femoral stem anteversion postoperatively with three-dimensional computed tomography reconstruction of the femur, using both the distal femoral epicondyles and the posterior femoral condyles to determine the femoral diaphyseal plane. The bias and precision of the measurements were calculated.

Results: The surgeon's estimate of femoral stem anteversion was a mean (and standard deviation) of 9.6° ± 7.2° (range, –8° to 28°). The anteversion of the stem measured by computed tomography was a mean of 10.2° ± 7.5 ° (range, –8.6° to 27.1°) (p = 0.324). The correlation coefficient between the surgeon's estimate and the computed tomographic measurement was 0.688; the intraclass coefficient was 0.801. Anteversion measured by computed tomography found that forty-nine stems (45%) were between 10° and 20° of anteversion; forty-three stems (39%) were between 0° and 9° of femoral anteversion; eight stems (7%) were in anteversion of >20°; and nine stems (8%) were in retroversion.

Conclusions: The surgeon's estimation of the anteversion of the cementless femoral stem has poor precision and is often not within the intended range of 10° to 20° of anteversion. The implications of this finding increase the importance of achieving a safe range of motion by evaluating the combined anteversion of the stem and the cup.

Level of Evidence: Diagnostic Level I. See Instructions to Authors for a complete description of levels of evidence.

Background: Fractures of the volar articular margin of the distal part of the radius with volar radiocarpal subluxation (volar shearing, or Barton, fractures) can be accompanied by a fracture of the dorsal metaphyseal cortex. We tested the null hypothesis that there is no difference in wrist function or health status after open reduction and plate-and-screw fixation between volar shearing fractures with a dorsal cortical fracture (complete articular, AO Type C) and those without a dorsal cortical fracture (partial articular, AO Type B).

Methods: In a multicenter cohort study, fifty-seven patients with a volar marginal shearing fracture of the distal part of the radius and volar radiocarpal subluxation were followed for at least one year following plate-and-screw fixation. Thirty-seven patients who also had a dorsal metaphyseal cortical fracture (Type-C fracture) were compared with twenty patients who had a partial articular (Type-B) fracture. The two cohorts were analyzed for differences in wrist and forearm motion, grip strength, pain, and the Gartland and Werley, Disabilities of the Arm, Shoulder and Hand (DASH), and Short Form-36 (SF-36) scores at six, twelve, and twenty-four months postoperatively. Differences in mean values and their change over time were determined.

Results: There were no significant differences between patients with a Type-B fracture and those with a Type-C fracture with respect to motion, grip strength, or the Gartland and Werley or DASH score at any time point. At six months after the surgery, the patients with a Type-B volar shearing fracture reported a mean score for pain in motion of 0.5 point on a 10-point visual analogue scale compared with 2.2 points for patients with a Type-C fracture (difference in means, 1.7 points [95% confidence interval, 0.7 to 2.6 points]; p < 0.001), but no significant difference was seen at twelve or twenty-four months.

Conclusions: Volar shearing fractures are usually complete articular, Type-C injuries. Patients with a Type-C volar shearing fracture experience more pain during early recovery, but ultimately their outcome is comparable with that for patients with a Type-B (partial articular) volar shearing fracture.

Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Background: Epidemiological data on the incidence of surgical treatment of pediatric fractures are sparse. Our aim was to determine the incidence of in-hospital-treated fractures and of the surgical treatment of these fractures in children and adolescents.

Methods: National Discharge Register data on pediatric fractures (in patients younger than the age of eighteen years) treated in the hospital in Finland between 1997 and 2006 were evaluated.

Results: During the ten-year follow-up period, the incidence (per 100,000 persons) of fractures leading to hospitalization increased by 13.5% (from 319 in 1997 to 362 in 2006; p < 0.001). This change resulted mainly from an increase in the incidence of hospital-treated upper-extremity fractures (23% increase; from 189 in 1997 to 232 in 2006). The incidence of primary fracture surgery increased by 20% (from 237 in 1997 to 284 in 2006; p < 0.001). The incidences of surgery for upper-extremity, lower-extremity, and axial fractures increased by 28%, 3.9%, and 10.7%, respectively. Within the upper-extremity-fracture group, the incremental increase was mainly due to an increase in forearm fracture surgery (62% increase; from fifty-five in 1997 to eighty-nine in 2006) (p < 0.001).

Conclusions: Operative treatment of children's fractures has increased markedly during the last ten years. Evidence-based medical and economic data supporting this change in practice are sparse.

The purpose of this study was to update the results, at a minimum of thirty-five years, in a single-surgeon series of primary Charnley total hip arthroplasties performed with cement. Twelve patients (fifteen hips) were alive, 249 patients (314 hips) had died, and one patient (one hip) had been lost to follow-up. Seven of the hips in the living patients had required at least one revision; 290 (88%) of the original group of total hip prostheses either continued to function or were in patients who had died. Since the time of a thirty-year study of this cohort, one hip that had previously been revised because of acetabular loosening required an additional revision because of acetabular loosening and two additional hips had evidence of radiographic loosening (of one acetabular and one femoral component). The survival rate with revision for any reason as the end point was 78%. This end result study should provide a benchmark for subsequent procedures and designs with the caveat that patient life expectancy will likely continue to increase and modern-design implants are being used in younger patients.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Background: Open reduction for the treatment of hip dislocation due to developmental dysplasia of the hip in children of walking age is frequently combined with either a femoral varus derotation osteotomy or an innominate osteotomy; however, it remains unclear which of these procedures is preferable in terms of subsequent hip development. The purpose of the present study was to compare acetabular development in patients managed for dislocation of the hip with open reduction combined with one of the two osteotomies.

Methods: Patients between fifteen months and four years of age with hip dislocations that were treated at two different centers were compared. At one center, open reduction combined with a femoral varus derotation osteotomy was performed (thirty-eight patients), and at the other, open reduction combined with an innominate osteotomy was performed (thirty-three patients). In each group, one surgeon performed all of the operations. A total of 490 postoperative radiographs that were made over a mean follow-up period of 6.2 years were analyzed. We compared the change in acetabular index as well as several other radiographic criteria of acetabular development and hip stability over time.

Results: After osteotomy, the acetabular index improved in both groups; however, the acetabular index in patients who underwent a varus derotation osteotomy never improved as much as that in patients who underwent an innominate osteotomy, with a mean difference of 9.5 after four years (p < 0.0001). Similarly, the innominate osteotomy group demonstrated better acetabular architecture and hip stability over time as quantified by the change in the acetabular floor thickness (p = 0.03), lateral centering ratio (p < 0.0001), and superior centering ratio (p < 0.0001).

Conclusions: In the present series, acetabular remodeling after open hip reduction and innominate osteotomy was more effective for reversing acetabular dysplasia and maintaining hip stability than open reduction combined with a femoral varus derotation osteotomy was. Long-term follow-up is necessary to determine whether the more favorable hip development following innominate osteotomy is associated with a lower incidence of premature degenerative hip disease.

Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.

Background: Ischemia-reperfusion injury plays an important role in limb salvage following limb ischemia. The purpose of the present study was to evaluate the effect of local hypothermia and chemical modulators on microvascular permeability following ischemia-reperfusion injury in skeletal muscle.

Methods: Sprague-Dawley rats were randomized into nine groups. Postcapillary venules of the extensor digitorum longus muscle were visualized with use of intravital microscopy. Following an intravenous bolus of fluorescein isothiocyanate-labeled albumin, the intravascular and extravascular space was examined for leak. Rats in the sham group underwent a one-hour mock ischemic period without the application of a femoral artery tourniquet, followed by one hour of mock reperfusion. The treatment groups (n = 5 in each group) had the tourniquet applied for one hour, followed by one hour of reperfusion at 10°C (cold) alone, at 10°C with nitric oxide synthase inhibitor, at 10°C with heme oxygenase inhibitor, at 10°C with a combination of inhibitors, at 34°C (warm) alone, at 34°C with a heme oxygenase inducer, at 34°C with a nitric oxide synthase inducer, or at 34°C with a combination of inducers.

Results: Rats in the sham group did not show a significant increase in microvascular permeability. Rats in the warm ischemia/reperfusion group displayed significant increases in microvascular permeability, as did the rats that received inhibitors of heme oxygenase and nitric oxide synthase at 10°C. No significant increase in microvascular permeability was observed in the animals in the cold ischemia/reperfusion group or in animals that received inducers of heme oxygenase and nitric oxide synthase at 34°C.

Conclusions: Local hypothermia protects skeletal muscle from increased microvascular permeability following ischemia-reperfusion injury. This protective effect is also seen with the induction of the nitric oxide synthase and heme oxygenase systems at physiologic temperature. We also have shown that the protective effects of hypothermia are blocked by giving heme oxygenase and nitric oxide synthase inhibitors while keeping the muscle hypothermic. These findings demonstrate that heme oxygenase and nitric oxide synthase play a combined role in ischemia-reperfusion injury, suggesting possible pathways for clinical intervention to modulate injury seen following trauma, tourniquet use, vascular surgery, and microvascular surgery.

Clinical Relevance: The present study provides evidence for the use of local hypothermia following ischemia-reperfusion-related tissue injury and provides biochemical insight for future pharmacologic intervention.

Background: Intraoperative stress testing is required for the detection of syndesmosis instability following an ankle fracture. The present study compared two stress tests for the detection of syndesmotic injury.

Methods: A true mortise radiograph of the ankle was made for fourteen cadaver joints. Specimens were randomized into two groups to simulate ligament and syndesmosis injury on the basis of the Danis-Weber classification system. In the first group, the anterior inferior tibiofibular ligament was divided first (Weber B_r), followed sequentially by division of the interosseous membrane (Weber C) and the deltoid ligament. In the second group, the deltoid ligament was divided first, followed by the anterior inferior tibiofibular ligament. Radiographs were made at each stage with use of two methods of stressing the ankle mortise: (1) external rotation of the foot with an external moment of 7.5 Nm, and (2) application of a lateral force of 100 N. Tibiofibular overlap, tibiofibular clear space, and medial clear space were measured.

Results: Lateral stress produced a significantly greater increase in the tibiofibular clear space than did the external rotation test for Weber C injuries and Weber C plus deltoid ligament injuries. A greater increase in the tibiofibular clear space was noted during the lateral stress test when both the deltoid and the anterior inferior tibiofibular ligament had been sectioned (p < 0.05). The external rotation stress test produced a significant increase in the medial clear space in the presence of isolated anterior inferior tibiofibular ligament and deltoid ligament injuries (p < 0.05).

Conclusions: For the detection of syndesmotic instability at the site of ankle fractures on stress radiographs, the lateral stress test appeared to be superior to the external rotation stress test in this cadaver model.

Clinical Relevance: The present study gives insight into the types of ligament damage that will produce a positive result on stress radiographs with use of two common intraoperative stress tests. Establishment of clinical correlation with the results of this cadaver model is necessary in order to develop operative guidelines.

Background: Loss of cyclooxygenase-2 activity is known to impair fracture-healing in animal models and to inhibit heterotopic ossification in humans. Cyclooxygenase-2 is the rate-limiting enzyme involved in the conversion of arachidonic acid into prostaglandins. Arachidonic acid also is a substrate for 5-lipoxygenase, which catalyzes the initial steps in leukotriene synthesis. In contrast to cyclooxygenase-2, genetic ablation of 5-lipoxygenase accelerates and enhances fracture-healing in mice. The goal of this study was to determine if systemic inhibition of 5-lipoxygenase with an orally delivered drug could accelerate fracture-healing.

Methods: Closed femoral fractures were made in Sprague-Dawley rats. The rats were treated with oral doses of vehicle (ninety-five rats), celecoxib (fifty-nine rats), or AA-861 (a 5-lipoxygenase inhibitor; eighty-nine rats). Fracture-healing was measured with use of radiographs, histomorphometry, and biomechanical testing. Effects of drug treatments on callus cell proliferation and gene expression were determined by incorporation of bromodeoxyuridine and quantitative polymerase chain reactions, respectively.

Results: AA-861 treatment decreased fracture-bridging time, significantly increased early callus cartilage (5.6-fold; p < 0.001) and bone formation (4.2-fold; p = 0.015), and significantly increased callus mechanical properties compared with the vehicle-treated rat fractures. Callus cell proliferation rate was increased by AA-861 treatment, compared with vehicle, at day 2 after fracture (3.68% compared with 2.08%; p < 0.001; 95% confidence interval, –2.81 to –0.039) but was reduced by celecoxib treatment at day 4 after fracture (4.22% compared with 1.84%; p < 0.001; 95% confidence interval, 2.27 to 4.07). At day 10 after fracture, AA-861 and celecoxib treatment increased Type-II collagen mRNA levels (16.0-fold and 6.1-fold, respectively; p < 0.001 for both), but only AA-861 treatment caused an increase in Type-X collagen mRNA (6.3-fold; p < 0.001). AA-861 treatment significantly increased cyclooxygenase-2 (4.0-fold at day 10; p < 0.001) and osteopontin mRNA levels (3.6-fold at day 7; p = 0.024), while decreasing 5-lipoxygenase mRNA levels (5.6-fold at day 4; p < 0.001).

Conclusions: Systemic inhibition of 5-lipoxygenase with an orally delivered drug significantly accelerated and enhanced fracture-healing in this rat model. Gene expression analysis indicates that cyclooxygenase-2 is necessary for callus chondrocytes to progress into hypertrophy so as to complete endochondral ossification. Conversely, inhibition of 5-lipoxygenase alters the inflammatory response, which enhances callus chondrocyte hypertrophy and accelerates endochondral ossification.

Clinical Relevance: These results suggest a novel approach to the treatment of human fractures and demonstrate that arachidonic acid metabolism can be manipulated to inhibit or accelerate fracture-healing, underscoring the importance of this pathway in bone regeneration.

Background: Hip abductors are the most important muscles around the hip joint. It is therefore essential to assess their function in a valid and reliable way. Since the optimal body posture for the assessment of hip abductor strength is unknown, we tested the validity and reliability of unilateral hip abductor strength assessment in three different body positions. We hypothesized that the validity would be better in the side-lying position because of the consistent stabilization of the contralateral (untested) hip.

Methods: Sixteen healthy subjects participated in two identical testing sessions. Unilateral isometric hip abductor muscle strength was measured, with use of a stabilized commercial dynamometer, with the subject in the side-lying, supine, and standing positions. Construct validity was based on concomitant recordings of gluteus medius electromyographic activity from the tested and contralateral hips. The body position permitting greater muscle activation and abductor strength on the tested hip, while minimizing muscle activation in the contralateral hip (that is, lower contralateral-to-tested electromyographic ratio), was considered the most valid. Coefficients of variation, the Bland and Altman limits of agreement, and intraclass correlation coefficients were calculated to determine test-retest reliability of hip abductor strength.

Results: Maximal hip abductor strength was significantly higher in the side-lying position compared with the standing and supine positions (p < 0.05). The contralateral-to-tested electromyographic ratio for the side-lying position was significantly lower than that for the supine and the standing position (p < 0.01). Test-retest reliability of strength measurements in terms of coefficients of variation (3.7% for side-lying, 6.1% for supine, and 4.2% for standing) and limits of agreement (±6.9% for side-lying, ±8.4% for supine, and ±7.5% for standing) was better in the side-lying position. All intraclass correlation coefficients were high to moderate (0.90 for side-lying, 0.83 for supine, and 0.88 for standing).

Conclusions: The side-lying body position offers the most valid and reliable assessment of unilateral hip abductor strength.

Clinical Relevance: We recommend the use of the side-lying body position whenever hip abductor function is assessed.

Background: Topical 5-fluorouracil has been reported to reduce adhesions in animal models of tenolysis. The purpose of this study was to investigate the effects of topical 5-fluorouracil on adhesion formation after tendon repairs were subjected to immediate postoperative rehabilitation in a canine model in vivo.

Methods: Sixty dogs were randomly assigned to either a 5-fluorouracil treatment (thirty dogs) or a control group (thirty dogs). Each treatment group was then divided into three survival time points: ten days, twenty-one days, and forty-two days. The second and fifth flexor digitorum profundus tendons from each dog were fully lacerated at the zone-II area and then were repaired. Passive motion therapy started at day 5 postoperatively and continued until the dogs were killed. The repaired tendons were evaluated for normalized work of flexion, gliding resistance, repair strength, gene expression for type-I and type-III collagen and transforming growth factor-β1, and histological appearance.

Results: The normalized work of flexion of the repaired tendons treated with 5-fluorouracil was significantly lower than that of the repaired tendons without 5-fluorouracil treatment at ten days. However, there was no significant difference between treated and untreated tendons at twenty-one and forty-two days. There was also no significant difference in gliding resistance, repair failure strength, or stiffness between treated and untreated tendons at any time point, or in the gross or histological appearance of adhesions at the time of killing. The expression of types-I and III collagen and transforming growth factor-β1 of the repaired tendon with 5-fluorouracil treatment was significantly lower than that of the tendons without treatment at ten days postoperatively, but not at twenty-one or forty-two days.

Conclusions: Although 5-fluorouracil treatment can reduce adhesions in in vivo models of tenolysis, this treatment had only a transient effect in an in vivo model of tendon repair that included passive motion.

Clinical Relevance: Topical 5-fluorouracil, at the dosing regimen tested in this study, does not appear to offer a major benefit over early postoperative motion protocols alone in the treatment of flexor tendon lacerations.

Background: Bacterial biofilms play a major role in chronic orthopaedic infections. Recently, farnesol (an antifungal agent) has been shown to express antimicrobial activities against Staphylococcus aureus and Streptococcus mutans. However, the effects of farnesol on the formation of bacterial biofilms on orthopaedic biomaterials and its effects on osteoblasts have not been investigated, to our knowledge, and are therefore the focus of this study.

Methods: Biofilms of Staphylococcus aureus (Seattle 1945^GFPuvr) were grown on titanium alloy discs. The effects of soluble farnesol on biofilm formation with or without gentamicin were examined with fluorescence microscopy and in quantitative cultures. The effect of farnesol coated on titanium alloy discs was also investigated, as was the effect of the agent on MC3T3-E1 pre-osteoblastic cells cultured on titanium alloy discs.

Results: Soluble farnesol at a 30-mM concentration reduced the number of viable bacteria 10⁴-fold and completely inhibited biofilm formation. Low concentrations of soluble farnesol (0.03 to 3 mM) did not inhibit biofilm formation and did not potentiate the effect of a submaximal concentration of gentamicin. Dried farnesol on titanium alloy discs reduced the number of viable bacteria fiftyfold. The effect of farnesol on bacterial biofilm formation lasted for at least three days. Soluble farnesol added after the biofilm had already formed also reduced the final number of viable bacteria, by fifty-six-fold. Soluble farnesol (3-mM and 30-mM concentrations) inhibited spreading of the MC3T3-E1 cells.

Conclusions: In vitro, a high concentration of farnesol (30 mM) shows antimicrobial properties against bacterial biofilms; however, it also has a negative effect on pre-osteoblasts. Farnesol can also express antimicrobial activity when predried on titanium discs and when added to preformed biofilms.

Clinical Relevance: As musculoskeletal infections remain a complicated problem, development of novel interventions to enhance prevention or treatment is necessary. Our study provides a basic knowledge of the effectiveness of farnesol against Staphylococcus aureus biofilms on titanium alloy surfaces. Although farnesol may have a clinical role, additional investigations, both in vitro and in vivo, are needed.

Internal impingement of the shoulder refers to a constellation of pathologic conditions, including, but not limited to, articular-sided rotator cuff tears, labral tears, biceps tendinitis, anterior instability, internal rotation deficit, and scapular dysfunction.

Physiologic adaptations to throwing include increased external rotation, increased humeral and glenoid retroversion, and anterior laxity, all of which may predispose an individual to internal impingement.

Nonoperative treatment should always be attempted first, with a focus on increasing the range of motion and improving scapular function.

When an operative intervention is chosen, it is important to address microinstability in order to have a good outcome and prevent failure.

The glossary below provides definitions for several terms found in the structured abstracts of the Evidence-Based Orthopaedics section, many of which may not be familiar to orthopaedic surgeons.