Radiographic failure and rates of re-operation after acromioclavicular joint reconstruction: a comparison of surgical techniques.

AIMS: To compare radiographic failure and re-operation rates of anatomical coracoclavicular (CC) ligament reconstructional techniques with non-anatomical techniques after chronic high grade acromioclavicular (AC) joint injuries. PATIENTS AND METHODS: We reviewed chronic AC joint reconstructions within a region-wide healthcare system to identify surgical technique, complications, radiographic failure and re-operations. Procedures fell into four categories: (1) modified Weaver-Dunn, (2) allograft fixed through coracoid and clavicular tunnels, (3) allograft loop coracoclavicular fixation, and (4) combined allograft loop and synthetic cortical button fixation. Among 167 patients (mean age 38.1 years, (standard deviation (sd) 14.7) treated at least a four week interval after injury, 154 had post-operative radiographs available for analysis. RESULTS: Radiographic failure occurred in 33/154 cases (21.4%), with the lowest rate in Technique 4 (2/42 4.8%, p = 0.001). Half the failures occurred by six weeks, and the Kaplan-Meier survivorship at 24 months was 94.4% (95% confidence interval (CI) 79.6 to 98.6) for Technique 4 and 69.9% (95% CI 59.4 to 78.3) for the other techniques when combined. In multivariable survival analysis, Technique 4 had better survival than other techniques (Hazard Ratio 0.162, 95% CI 0.039 to 0.068, p = 0.013). Among 155 patients with a minimum of six months post-operative insurance coverage, re-operation occurred in 9.7% (15 patients). However, in multivariable logistic regression, Technique 4 did not reach a statistically significant lower risk for re-operation (odds ratio 0.254, 95% CI 0.05 to 1.3, p = 0.11). CONCLUSION: In this retrospective series, anatomical CC ligament reconstruction using combined synthetic cortical button and allograft loop fixation had the lowest rate of radiographic failure. TAKE HOME MESSAGE: Anatomical coracoclavicular ligament reconstruction using combined synthetic cortical button and allograft loop fixation had the lowest rate of radiographic failure.

The relationship between Parson's tubercle and the insertion of the anterior horn of the medial meniscus.

PURPOSE: The purpose of this investigation was to correlate the anatomic characteristics of the third intercondylar tubercle of Parsons (TITP) with the insertional variations of the anterior horn of the medial meniscus using precise measurements in an anatomic cadaver study. Our hypothesis was that the height of the TITP would correlate with the degree of inferior insertion of the medial meniscus. TYPE OF STUDY: A cadaver study using a convenience sample. METHODS: Twenty unpaired proximal tibia specimens without advanced arthritis were analyzed with a coordinate measuring machine using a 0.479-mm diameter probe. A reference plane was created using 3 reproducible points on the tibial surface. Measurements from the TITP included another reference plane through its base, which was used to calculate its absolute height. The locations of the anterior- and inferior-most insertional points of the anterior horn of the medial meniscus were also determined. Correlations between the height of the TITP and age were also made. RESULTS: The overall height of the TITP was found to correlate with the degree of inferior insertion of the anterior horn of the medial meniscus (r =.52, P =.019). No correlation was found with the anterior placement of the meniscus (r =.12, P =.629) or with the age of the specimen (r =.14, P =.592). CONCLUSIONS: This absolute height of the TITP correlates with the inferior location of the insertion of the anterior horn of the medial meniscus. This association suggests a developmental relationship between 2 anatomic structures within the knee.

Factors predictive of immobilization complications in pediatric polytrauma.

OBJECTIVES: To determine in a cohort of children with polytrauma which variables are predictive of the development of complications related to immobilization. DESIGN: A retrospective study of children with polytrauma and at least one major musculoskeletal injury. A stepwise forward logistic regression analysis was used to determine variables predictive of complications related to immobilization. PARTICIPANTS: Ninety-three children with polytrauma were studied; motor vehicle incidents accounted for 80 percent of the injuries. The average age was 8.0 +/- 4.1 years. There were 152 fractures in the ninety-three children. The average Modified Injury Severity Scale (MISS) was 24.5 +/- 13.6. There were thirty-five complications in twenty-two children, and four children died. RESULTS: Two variables were predictive of complications related to immobilization: age and MISS score. Complications related to immobilization were positively associated with being older than seven years of age (p = 0.027; odds ratio = 9.5; 95 percent confidence interval 1.4, 64.9) and having a MISS score greater than forty (p = 0.005; OR = 14.1; 95 percent confidence interval 2.2, 89.1). Timing of surgery showed a trend (p = 0.097) but did not reach statistical significance. CONCLUSIONS: Complications of immobilization in children with polytrauma are associated with age greater than seven years and a MISS score greater than forty. Further study is needed to evaluate the effect of early fracture stabilization. Timing of osteosynthesis showed a trend but did not reach statistical significance in this study.

Scoring of pediatric orthopaedic polytrauma: correlations of different injury scoring systems and prognosis for hospital course.

Trauma scoring systems were compared among themselves and to recovery variables in a cohort of 91 pediatric polytrauma patients with orthopaedic injuries. They included the Trauma Score (TS), Revised Trauma Score (RTS), Injury Severity Score (ISS), Modified Abbreviated Injury Severity Scale (MISS), Pediatric Trauma Score (PTS), and TRISS-b survival statistic. Significant correlations between scoring systems and hospital course parameters existed. TRISS-b had the strongest correlation for days in the intensive care unit and total complications (r2 = 0.59, 0.58). PTS correlated poorly with recovery variables when compared to other scoring systems. The TS correlated most strongly with ventilatory days and complications of immobilization (r2 = 0.77, 0.58). The TS should be used early in the assessment of the pediatric polytrauma patient, along with the TRISS-b statistic. If they predict prolonged intensive care unit and ventilatory days and hospital complications, operative fracture management should be strongly considered.

The effects of overuse combined with intrinsic or extrinsic alterations in an animal model of rotator cuff tendinosis.

An in vivo animal model was used to evaluate overuse and overuse plus intrinsic tendon injury or extrinsic tendon compression in the development of rotator cuff injury. Forty-four male Sprague-Dawley rats were divided into groups of 22. Each left shoulder received an intrinsic or extrinsic injury plus overuse (treadmill running), and each right shoulder received only overuse. Eleven rats from each group were sacrificed at 4 and 8 weeks. Supraspinatus tendons were evaluated histologically or geometrically and biomechanically. Ten rats constituted a cage-activity control group. Both supraspinatus tendons of the experimental groups had increases in cellularity and collagen disorganization and changes in cell shape compared with control tendons. Tendons with injury plus overuse exhibited a worse histologic grade than those with overuse alone. The cross-sectional area of both supraspinatus tendons of the experimental rats was significantly more than in control tendons. The area of the injury plus overuse tendons was increased on average compared with overuse-alone tendons. Biomechanically, the tissue moduli of overuse/intrinsic injury tendons at 4 weeks and those of the overuse/extrinsic injury tendons at 8 weeks were significantly lower than in control tendons. Tissue moduli of the overuse/injury tendons were significantly lower than in the overuse-alone tendons at 8 weeks. This study demonstrated that damage to the supraspinatus tendon can be caused by overuse and intrinsic injury, overuse and extrinsic compression, and overuse alone.

Optimal side plate fixation for unstable intertrochanteric hip fractures.

OBJECTIVES: To quantitatively determine the minimal screw number needed for stable side plate fixation to the femoral shaft in treating unstable intertrochanteric hip fractures. DESIGN: Laboratory/biomedics study. SETTING: Orthopaedic biomechanics laboratory. PATIENTS OR OTHER PARTICIPANTS: The convenience sample was made up of one saw bone, one steel pipe, and ten human cadaveric femur specimens. Human specimens were selected by ruling out pathology and excess osteopenia. Ten specimens were tested to completion. INTERVENTION: Telescoping hip screw and hip screw side plate secured with various numbered combinations of side plate screws. MAIN OUTCOME MEASURES: Decreases in tension experienced by all previously inserted screws when an additional screw was applied were recorded and labeled as "protection." RESULTS: Protection offered by a third screw on all previous screws was 787.3 newtons in the steel pipemodel, 71.2 newtons in the sawbone model, and 158.3 newtons in the human model (p < 0.005). A fourth bone screw did not decrease tension in previous screws by more than 11 newtons. The protective effect of the fourth screw on screw #3 increased with decreasing screw application torque by a maximum of 21.8 newtons (p < 0.005). CONCLUSION: This study suggests that three bone screws provide an optimal distribution of tensile forces. The insertional torque used to place screws, once screw-plate contact has been established, does not play a significant role in screw protection. Additional studies are needed to assess the role of cortical bone density, and cyclical loading and bending forces experienced by the side plate screws, before definite clinical recommendations can be made.