Novel Augmentation Technique for Patellar Tendon Repair Improves Strength and Decreases Gap Formation: A Cadaveric Study.

BACKGROUND: Patellar tendon ruptures commonly are repaired using transosseous patellar drill tunnels with modified-Krackow sutures in the patellar tendon. This simple suture technique has been associated with failure rates and poor clinical outcomes in a modest proportion of patients. Failure of this repair technique can result from gap formation during loading or a single catastrophic event. Several augmentation techniques have been described to improve the integrity of the repair, but standardized biomechanical evaluation of repair strength among different techniques is lacking. QUESTIONS/PURPOSES: The purpose of this study was to describe a novel figure-of-eight suture technique to augment traditional fixation and evaluate its biomechanical performance. We hypothesized that the augmentation technique would (1) reduce gap formation during cyclic loading and (2) increase the maximum load to failure. METHODS: Ten pairs (two male, eight female) of fresh-frozen cadaveric knees free of overt disorders or patellar tendon damage were used (average donor age, 76 years; range, 65-87 years). For each pair, one specimen underwent the standard transosseous tunnel suture repair with a modified-Krackow suture technique and the second underwent the standard repair with our experimental augmentation method. Nine pairs were suitable for testing. Each specimen underwent cyclic loading while continuously measuring gap formation across the repair. At the completion of cyclic loading, load to failure testing was performed. RESULTS: A difference in gap formation and mean load to failure was seen in favor of the augmentation technique. At 250 cycles, a 68% increase in gap formation was seen for the control group (control: 5.96 ± 0.86 mm [95% CI, 5.30-6.62 mm]; augmentation: 3.55 ± 0.56 mm [95% CI, 3.12-3.98 mm]; p = 0.02). The mean load to failure was 13% greater in the augmentation group (control: 899.57 ± 96.94 N [95% CI, 825.06-974.09 N]; augmentation: 1030.70 ± 122.41 N [95% CI, 936.61-1124.79 N]; p = 0.01). CONCLUSIONS: This biomechanical study showed improved performance of a novel augmentation technique compared with the standard repair, in terms of reduced gap formation during cyclic loading and increased maximum load to failure. CLINICAL RELEVANCE: Decreased gap formation and higher load to failure may improve healing potential and minimize failure risk. This study shows a potential biomechanical advantage of the augmentation technique, providing support for future clinical investigations comparing this technique with other repair methods that are in common use such as transosseous suture repair.

The Effect of Transiliac-Transsacral Screw Fixation for Pelvic Ring Injuries on the Uninjured Sacroiliac Joint.

OBJECTIVE: To evaluate the functional outcomes and pain in patients with unilateral posterior pelvic ring injuries treated with transiliac-transsacral screw fixation compared with unilateral iliosacral screw fixation. DESIGN: Retrospective comparative study. SETTING: Three academic level 1 trauma centers. PATIENTS/PARTICIPANTS: From a group of 866 patients with pelvic ring injuries treated surgically, 86 patients with unilateral pelvic ring injuries treated with transiliac-transsacral screws and 97 patients treated with unilateral iliosacral screws were identified. Thirty-six patients treated with transiliac-transsacral fixation and 26 patients treated with unilateral iliosacral screws met the inclusion criteria and participated. INTERVENTION: Patients were treated surgically for unstable pelvic ring injuries with either unilateral iliosacral screws or transiliac-transsacral screws at the discretion of the treating surgeon. MAIN OUTCOME MEASUREMENT: Majeed Pelvic Score. RESULTS: There was no significant difference in Majeed Pelvic Scores between patients treated with transiliac-transsacral screws and those treated with unilateral iliosacral screws (72.8 ± 23.7 vs. 70.4 ± 19.0, P = 0.66). There was no difference in side-specific Numeric Rating Scale pain scores between patients treated with transiliac-transsacral screws and those treated with unilateral iliosacral screws on the injured side (2.5 ± 3.1 vs. 2.0 ± 2.4, P = 0.46) or the uninjured side (1.7 ± 2.8 vs. 0.8 ± 1.7, P = 0.12). Mean follow-up was greater than 3 years with no difference between the groups (mean 1270 vs. 1242 days, P = 0.84). CONCLUSIONS: Treatment of unilateral pelvic ring injuries with transiliac-transsacral screws does not adversely affect or improve patient outcomes or subjective pain scores when compared with those treated with unilateral iliosacral screws. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Current Opinions on Fracture Follow-up: A Survey of OTA Members Regarding Standards of Care and Implications for Clinical Research.

OBJECTIVES: To determine current practice standards among Orthopaedic Trauma Association surgeons for postoperative fracture follow-up and to investigate the implications of these standards on clinical research. DESIGN: Survey. SETTING: Web-based survey. PARTICIPANTS: One hundred eighty-four orthopaedic trauma surgeons. METHODS: A web-based questionnaire was distributed to Orthopaedic Trauma Association members to identify standard postoperative radiographic and clinical follow-up duration. Assuming uneventful, complete fracture healing at 3 months, data were collected for 3 generic fracture types (diaphyseal, extra-articular metaphyseal, and intra-articular) and 3 specific fractures (femoral shaft, intertrochanteric, and tibial plateau). Suggested follow-up for clinical research was also investigated. RESULTS: For extra-articular fractures, standard radiographic and clinical follow-up were considered to be 6 months or less by greater than 70% of respondents. For intra-articular fractures, standard radiographic and clinical follow-up was considered to be 6 months or less by greater than 39% of respondents. The most common responses for radiographic follow-up were 3 months for extra-articular fractures (33%) and 12 months for intra-articular fractures (34%). The most common responses for clinical follow-up were 6 months for extra-articular fractures (37%) and 12 months for intra-articular fractures (35%). The majority (55%) indicated that follow-up to clinical and radiographic healing or the establishment of a nonunion should be the minimum follow-up for clinical fracture studies and 66% recommended follow-up to at least 1 year for functional outcome studies. CONCLUSIONS: Most surgeons follow-up patients with lower extremity extra-articular fractures (with uneventful healing) radiographically for 3-6 months and clinically for 6 months and slightly longer for intra-articular fractures. Many surgeons cease radiographic and clinical follow-up by 6 months. Therefore, retrospective fracture healing studies can only reasonably expect follow-up for 6 months. Publication requirements for longer follow-up of fracture-related studies would likely eliminated retrospective studies from consideration. Most surgeons support obtaining at least 1-year follow-up for clinical studies that include functional outcome. LEVEL OF EVIDENCE: Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.

Anterior cruciate ligament reconstruction in the skeletally immature: an anatomical study utilizing 3-dimensional magnetic resonance imaging reconstructions.

INTRODUCTION: Anatomic anterior cruciate ligament (ACL) reconstruction has proven to be a reliable method to restore knee stability. However, the risk of physeal arrest with transphyseal tunnel placement in skeletally immature patients has raised concern regarding this technique. Conservative nonoperative management also has its limitations resulting in meniscal and chondral damage that may lead to degenerative joint disease and poor return to sport. Researchers have used animal models to study the threshold of physeal damage producing growth deformity. The purpose of this study was to examine the distal femoral and proximal tibial physes and determine the damage produced by drilling transphyseal tunnels. In addition, we attempted to find a reproducible angle at which to drill the tibial tunnel for safe interference screw placement. To do this, we used a custom software module. METHODS: A custom software package designed by our team was used: Module for Adolescent ACL Reconstructive Surgery (MAARS). This module created a 3-dimensional model of the distal femur and proximal tibia. The data required for MAARS were sagittal and coronal T1 magnetic resonance imagings of at least 1.5 T. Thirty-one knee magnetic resonance imaging studies from patients aged 10 to 15 years old were used. The physes were segmented out to obtain volumetric measurements. Transphyseal tunnels were simulated based on the anatomic trajectory of the native ACL. The module calculated volume of physis was removed with the use of an 8-mm tunnel and the optimum angle for trajectory. RESULTS: Average volume of the tibial and femoral physis was 12,683.1 microL and 14,708.3 microL, respectively. The volume increased linearly with age. Average volume removed from the tibial and femoral physis was 318.4 microL and 306.29 microL, respectively. This represented 2.4% of the distal femoral physis and 2.5% of the proximal tibial physis. The volume percent removed decreased linearly with age.Manipulation of the variables demonstrates graft radius is the most critical parameter affecting the volume of physeal injury. Variation of graft diameter from 6 mm to 11 mm will increase volume percent removed from 2.3% to 7.8%, which averages 1.1% for every 1 mm increase. Increasing tunnel drill angle from 45 degrees to 70 degrees will decrease volume percent removed from 4.1% to 3.1% which averages 0.2% removed for each 5 degrees increase in drill angle. The average angle to maintain a distance of 20 mm from the proximal tibial physis was 65 degrees with a range of 40 degrees to 85 degrees. DISCUSSION: Less than 3% injury occurs when drilling an 8-mm tunnel across the physis. A vertical tunnel has minimal effect, but the tunnel diameter is critical. Interference screws can be placed safely to avoid the physis but requires careful planning. The MAARS module may be helpful in preoperative planning. LEVEL OF EVIDENCE: Diagnostic, level IV.