Bradley J. Nelson

The Incidence and Characteristics of Shoulder Instability at the United States Military Academy

Background The literature provides little information detailing the incidence of traumatic shoulder instability in young, healthy athletes. Hypothesis Shoulder instability is common in young athletes. Study Design Descriptive epidemiologic study. Methods We prospectively captured all traumatic shoulder instability events at the United States Military Academy between September 1, 2004, and May 31, 2005. Throughout this period, all new traumatic shoulder instability events were evaluated with physical examination, plain radiographs, and magnetic resonance imaging. Instability events were classified according to direction, chronicity, and type (subluxation or dislocation). Subject demographics, mechanism of injury, and sport were evaluated. Results Among 4141 students, 117 experienced new traumatic shoulder instability events during the study period; 11 experienced multiple events. The mean age of these 117 subjects was 20.0 years; 101 students were men (86.3%), and 16 were women (13.7%). The 1-year incidence proportion was 2.8%. The male incidence proportion was 2.9% and the female incidence proportion was 2.5%. Eighteen events were dislocations (15.4%), and 99 were subluxations (84.6%). Of the 99 subluxations, 45 (45.5%) were primary events, while 54 (54.5%) were recurrent. Of the 18 dislocations, 12 (66.7%) were primary events, while 6 (33.3%) were recurrent. The majority of the 117 events were anterior in nature (80.3%), while 12 (10.3%) were posterior, and 11 (9.4%) were multidirectional. Forty-four percent (43.6%) of the instability events experienced were as a result of contact injuries, while 41.0% were a result of noncontact injuries, including 9 subluxations caused by missed punches during boxing; information was unavailable for the remaining 15%. Conclusion Glenohumeral instability is a common injury in this population, with subluxations comprising 85% of instability events.

Functional outcome of thoracolumbar burst fractures managed with hyperextension casting or bracing and early mobilization

Study Design A retrospective study to review the results of unstable thoracolumbar burst fractures managed with casting or bracing and early ambulation in neurologically healthy patients. Objectives To determine the clinical outcome of patients with unstable burst fractures of the thoracolumbar spine treated without surgery, and to identify any variables that may adversely influence the final outcome. Summary of Background Data The management of unstable fractures of the thoracolumbar spine as described by Bedbrook involves a period of recumbency for 6–8 weeks followed by gradual mobilization. Newer techniques of surgical stabilization of the fracture and decompression of the neural elements have become popular because immediate stability of the spine is created and because the need for prolonged bedrest and hospitalization is eliminated. There have been only three reports in the literature describing the nonoperative management of these fractures with early mobilization; some authors believe that this is appropriate only if the posterior column is intact. The results reported in the literature of nonoperative management of thoracolumbar burst fractures have indicated that this is an effective method of management. Methods A retrospective review of 26 patients with unstable burst fractures in the thoracolumbar region (T11‐L2) was performed; follow‐up evaluation was obtained from 24 patients. Clinical follow‐up examination was performed by the use of a questionnaire in which the patients were asked to rate their pain, ability to work, ability to perform in recreational activities, and their overall satisfaction with treatment. Results Mean follow‐up time for the 24 patients was 34.3 months. Mean duration of hospitalization was 8.2 days; those patients who did not have injuries other than their spine fracture had a mean hospitalization time of 5.9 days. Kyphotic deformity could be corrected with hyperextension casting but tended to recur during the course of mobilization and healing. No correlation was found between kyphosis and clinical outcome. At final follow‐up evaluation, 19 patients (79%) had little or no pain; 18 patients (75%) had returned to work; 18 (75%) stated that they had little or no restrictions in their ability to work, and 16 (67%) stated that they had little or no restrictions in their ability to participate in recreational activities. Only one patient (4%) reported being dissatisfied with the initial nonoperative treatment of his spine fracture. Ten patients were found to have evidence of spinous process widening on plain films; there was no significant difference in the clinical or radiographic outcome of these 10 patients when compared with the 14 others who did not have interspinous widening. Conclusions Nonoperative management of thoracolumbar burst fractures with hyperextension casting or bracing was proven to be a safe and effective method of treatment in selected patients. Clinical results were favorable; no neurologic deterioration was observed; hospitalization times were minimized, and patient satisfaction was high. The authors do not believe that ligamentous injury of the posterior column is a contraindication to nonoperative management of thoracolumbar burst fractures.

Incidence of Glenohumeral Instability in Collegiate Athletics

Background Glenohumeral instability is a common injury sustained by young athletes. Surprisingly, little is known regarding the incidence of glenohumeral instability in collegiate athletes or the relevant risk factors for injury. A better understanding of the populations most at risk may be used to develop preventive strategies. Hypothesis The incidence of glenohumeral instability in collegiate athletics is high, and it is affected by sex, sport, type of event, and mechanism of injury. Study Design Descriptive epidemiologic study. Methods The National Collegiate Athletic Association injury database was queried for all glenohumeral instability events occurring between the years 1989 and 2004. An analysis of the injuries was performed by sport, activity (competition versus practice), sex, type of event (primary versus recurrent), mechanism of injury, and time loss from athletic performance. Incidence rates and incidence rate ratios were calculated. Results A total of 4080 glenohumeral instability events were documented for an incidence rate of 0.12 injuries per 1000 athlete exposures. The sport with the greatest injury rate was mens spring football, with 0.40 injuries per 1000 athlete exposures. Overall, athletes sustained more glenohumeral instability events during games than practices (incidence rate ratio [IRR], 3.50; 95% confidence interval [CI], 3.29-3.73). Male athletes sustained more injuries than did female athletes (IRR, 2.67; 95% CI, 2.43-2.93). Female athletes were more likely to sustain an instability event as the result of contact with an object (IRR, 2.43; 95% CI, 2.08-2.84), whereas male athletes were more likely to sustain an event from player contact (IRR, 2.74; 95% CI, 2.31-3.25). Time lost to sport (>10 days) occurred in 45% of glenohumeral instability events. Conclusion Glenohumeral instability is a relatively common injury sustained by collegiate athletes. More injuries occurred during competition and among male athletes.

Long-term Follow-up of Acute Arthroscopic Bankart Repair for Initial Anterior Shoulder Dislocations in Young Athletes

Background Little is known of the long-term results of acute arthroscopic Bankart repair for first-time traumatic anterior glenohumeral dislocations. Hypothesis Acute arthroscopic Bankart repair for first-time traumatic anterior glenohumeral dislocations will provide good results at long-term follow-up. Study Design Case series; Level of evidence, 4. Methods The authors evaluated a cohort of young patients who sustained first-time anterior glenohumeral dislocations and were acutely treated with arthroscopic Bankart repair using bioabsorbable tacks. Subjective outcome measures were obtained at a mean follow-up of 11.7 years (range, 9.1-13.9 years). Results Thirty-nine patients (40 shoulders) were available of the original cohort of 49 shoulders (82%). Two of the 9 who were lost to follow-up had revision surgery before being lost and are carried forward in the calculations of recurrent instability and revision surgery but are not included in the calculation of the functional scores. The mean Single Assessment Numeric Evaluation was 91.7, the mean Western Ontario Shoulder Instability score was 371.7, the mean subjective Rowe score was 25.3, the mean Simple Shoulder Test was 11.1, the mean American Shoulder and Elbow Society score was 90.9, the mean Short Form-36 Physical Component score was 94.4, and the mean Tegner score was 6.5. Six patients sustained recurrent dislocations for a redislocation rate of 14.3%. Nine patients (21.4%) reported experiencing subluxation events. Six patients (14.3%) underwent revision stabilization surgery. Conclusion At long-term follow-up, acute arthroscopic Bankart repair for first-time traumatic anterior glenohumeral dislocations resulted in excellent subjective function and return to athletics in young, active patients with an acceptable rate of recurrence and reoperation.

Antimicrobial efficacy of external fixator pins coated with a lipid stabilized hydroxyapatite/chlorhexidine complex to prevent pin tract infection in a goat model.

BACKGROUND Pin tract infection is a common complication of external fixation. An antiinfective external fixator pin might help to reduce the incidence of pin tract infection and improve pin fixation. METHODS Stainless steel and titanium external fixator pins, with and without a lipid stabilized hydroxyapatite/chlorhexidine coating, were evaluated in a goat model. Two pins contaminated with an identifiable Staphylococcus aureus strain were inserted into each tibia of 12 goats. The pin sites were examined daily. On day 14, the animals were killed, and the pin tips cultured. Insertion and extraction torques were measured. RESULTS Infection developed in 100% of uncoated pins, whereas coated pins demonstrated 4.2% infected, 12.5% colonized, and the remainder, 83.3%, had no growth (p < 0.01). Pin coating decreased the percent loss of fixation torque over uncoated pins (p = 0.04). CONCLUSION These results demonstrate that the lipid stabilized hydroxyapatite/chlorhexidine coating was successful in decreasing infection and improving fixation of external fixator pins.

Pathoanatomy of first-time, traumatic, anterior glenohumeral subluxation events.

BACKGROUND Relative to dislocations, glenohumeral subluxation events have received little attention in the literature, despite a high incidence in young athletes. The pathoanatomy of first-time, traumatic, anterior subluxation events has not been defined, to our knowledge. METHODS As part of a prospective evaluation of all cases of shoulder instability sustained during one academic year in a closed cohort of military academy cadets, a total of thirty-eight first-time, traumatic, anterior glenohumeral subluxation events were documented. Clinical subluxation events were defined as incomplete instability events that did not require a manual reduction maneuver. Twenty-seven of those events were evaluated with plain radiographs and magnetic resonance imaging within two weeks after the injury and constitute the cohort studied. Magnetic resonance imaging studies were independently evaluated by a musculoskeletal radiologist blinded to the clinical history. Arthroscopic findings were available for the fourteen patients who underwent arthroscopic surgery. RESULTS Of the twenty-seven patients who sustained a first-time, traumatic, anterior subluxation, twenty-two were male and five were female, and their mean age was twenty years. Plain radiographs revealed three osseous Bankart lesions and two Hill-Sachs lesions. Magnetic resonance imaging revealed a Bankart lesion in twenty-six of the twenty-seven patients and a Hill-Sachs lesion in twenty-five of the twenty-seven patients. Of the fourteen patients who underwent surgery, thirteen had a Bankart lesion noted during the procedure. Of the thirteen patients who chose nonoperative management, four experienced recurrent instability. Two of the thirteen patients left the academy for nonmedical reasons and were lost to follow-up. The remaining seven patients continued on active-duty service and had not sought care for a recurrent instability event at the time of writing. CONCLUSIONS First-time, traumatic, anterior subluxation events result in a high rate of labral and Hill-Sachs lesions. These findings suggest that clinical subluxation events encompass a broad spectrum of incomplete events, including complete separations of the articular surfaces with spontaneous reduction. A high index of suspicion for this injury in young athletes is warranted, and magnetic resonance imaging may reveal a high rate of pathologic changes, suggesting that a complete, transient luxation of the glenohumeral joint has occurred.

Patellar Tendon Versus Hamstring Tendon Autografts for Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial Using Similar Femoral and Tibial Fixation Methods

Background Controversy remains over the most appropriate graft for anterior cruciate ligament reconstruction. Hypothesis There is no significant difference in outcomes after 4-strand hamstring and patellar tendon autograft anterior cruciate ligament reconstructions using similar fixation techniques. Study Design Randomized controlled trial; Level of evidence, 1. Methods Between August 2000 and May 2003, 64 Keller Army Hospital patients with complete anterior cruciate ligament tears were randomized to hamstring (n = 32) or patellar tendon (n = 32) autograft anterior cruciate ligament reconstruction. Operative graft fixation and rehabilitative techniques were the same for both groups. Follow-up assessments included the Single Assessment Numeric Evaluation score, Lysholm score, International Knee Documentation Committee score, and Knee Injury and Osteoarthritis Outcome Score. Postoperative radiographs were analyzed for tunnel location and orientation. Results Eleven women and 53 men were randomized. Eighty-three percent of the patients (53 of 64) had follow-up of greater than 2 years, or to the point of graft rupture or removal (average follow-up, 36 months). Four hamstring grafts (12.5%) and three patellar tendon grafts (9.4%) (P = .71) ruptured. One deep infection in a hamstring graft patient necessitated graft removal. Forty-five of the 56 patients with intact grafts had greater than 2-year follow-up. Patients with patellar tendon grafts had greater Tegner activity scores (P = .04). Single Assessment Numeric Evaluation scores were 88.5 (95% confidence interval: 83.1, 93.8) and 90.1 (95% confidence interval: 85.2, 96.1) for the hamstring and patellar tendon groups, respectively (P = .53). Lysholm scores were 90.3 (95% confidence interval: 84.4, 96.1) and 90.4 (95% confidence interval: 84.5, 96.3) for the hamstring and patellar tendon groups, respectively (P = .97). There were no significant differences in knee laxity, kneeling pain, isokinetic peak torque, International Knee Documentation Committee score, or Knee Injury and Osteoarthritis Outcome Scores. Postoperative graft rupture correlated with more horizontal tibial tunnel orientation. Conclusion Hamstring and patellar tendon autografts provide similar objective, subjective, and functional outcomes when assessed at least 2 years after anterior cruciate ligament reconstruction.

Biomechanical Analysis of an Isolated Fibular (Lateral) Collateral Ligament Reconstruction Using an Autogenous Semitendinosus Graft

Background The fibular collateral ligament is the primary stabilizer to varus instability of the knee. Untreated fibular collateral ligament injuries can lead to residual knee instability and can increase the risk of concurrent cruciate ligament reconstruction graft failures. Anatomic reconstructions of the fibular collateral ligament have not been biomechanically validated. Purpose To describe an anatomic fibular collateral ligament reconstruction using an autogenous semitendinosus graft and to test the hypothesis that using this reconstruction technique to treat an isolated fibular collateral ligament injury will restore the knee to near normal stability. Study Design Controlled laboratory study. Methods Ten nonpaired, fresh-frozen cadaveric knees were biomechanically subjected to a 10 N·m varus moment and 5 N·m external and internal rotation torques at 0°, 15°, 30°, 60°, and 90° of knee flexion. Testing was performed with an intact and sectioned fibular collateral ligament, and also after an anatomic reconstruction of the fibular collateral ligament with an autogenous semitendinosus graft. Motion changes were assessed with a 6 degree of freedom electromagnetic motion analysis system. Results After sectioning, we found significant increases in varus rotation at 0°, 15°, 30°, 60°, and 90°, external rotation at 60° and 90°, and internal rotation at 0°, 15°, 30°, 60°, and 90° of knee flexion. After reconstruction, there were significant decreases in motion in varus rotation at 0°, 15°, 30°, 60°, and 90°, external rotation at 60° and 90°, and internal rotation at 0°, 15°, and 30° of knee flexion. In addition, we observed a full recovery of knee stability in varus rotation at 0°, 60°, and 90°, external rotation at 60° and 90°, and internal rotation at 0° and 30° of knee flexion. Conclusion An anatomic fibular collateral ligament reconstruction restores varus, external, and internal rotation to near normal stability in a knee with an isolated fibular collateral ligament injury. Clinical Significance An anatomic reconstruction of the fibular collateral ligament with an autogenous semitendinosus graft is a viable option to treat nonrepairable acute or chronic fibular collateral ligament tears in patients with varus instability.

Autograft Versus Allograft: An Economic Cost Comparison of Anterior Cruciate Ligament Reconstruction

PURPOSE The purpose of this study was to compare the costs associated with anterior cruciate ligament (ACL) reconstruction with either bone-patellar tendon-bone (BPTB) autograft or BPTB allograft. METHODS Surgical costs are reported, including supply costs, based on invoice costs per item used per procedure, and personnel costs calculated as cost per minute. All operations were performed at an ambulatory surgery center between March 2005 and March 2006. A total of 160 patients underwent primary ACL reconstruction with either BPTB autograft (n = 106) or BPTB allograft (n = 54). Procedure cost data were retrieved from a financial management database and divided into various categories for comparison of the 2 groups. Payment data were provided by the surgery centers billing office. RESULTS The total mean cost per case was

Arthroscopic Management of Glenohumeral Instability

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