Faculty Bibliography

PURPOSE: To investigate the biomechanical properties of the load shifting following opening-wedge distal femoral varus osteotomies (DFVOs) and determine the osteotomy correction needed to unload the lateral compartment. METHODS: Five human cadaveric knees were tested with a load of 500 N of axial compression. Medial and lateral tibiofemoral compartment contact area and pressure were assessed utilizing a modified F-scan pressure-sensitive sensor. The knees were tested in their baseline anatomic alignment, 10 degrees valgus malalignment and following corrective DFVOs of 5 degrees , 10 degrees and 15 degrees . The load shifting effect of the various DFVO correction angles was analysed using a one-way ANOVA to determine the correction angle necessary to unload the lateral compartment. RESULTS: Gradually shifting the loading vector medially with increasing DFVO angles resulted in a decrease in the mean contact area and mean contact pressures in the lateral compartment with progressive increases in the medial compartment. The largest reduction in lateral compartment pressure and contact area was seen with the 15 degrees osteotomy with a 25 % decrease in mean contact pressure and 20 % decrease in mean maximum contact pressure and mean contact area when compared to the 10 degrees valgus-malaligned knee. For the 10 degrees valgus knee, a 15 degrees correction resulted in near-normal contact pressures and areas compared with the knee in normal anatomic alignment. CONCLUSION: Progressive unloading of the lateral tibiofemoral compartment occurred with increasing DFVO correction angles. Clinically, when performing a DFVO for valgus malalignment, surgeons should consider overcorrecting the osteotomy by 5 degrees to restore near-normal contact pressures and contact areas in the lateral compartment rather than the traditional teaching of correcting to neutral alignment.

With the increasing incidence of anterior cruciate ligament (ACL) reconstruction in women and younger patients, the optimal graft choice in the young female patient has become the subject of much debate. This study aimed to evaluate patient-reported outcomes, objective knee stability, complication rates, and the incidence of failure after ACL reconstruction using bone-patellar tendon-bone (BPTB) autograft compared with hamstring (HS) autograft in young female patients. Female patients who underwent primary ACL reconstruction with BPTB or HS autograft between ages 15 and 25 years were identified. Medical records were reviewed for postoperative complications and subsequent procedures on the operative knee. Patients were evaluated with functional surveys, physical examination including Lachman and pivot-shift tests, and arthrometric testing with a KT-1000 arthrometer. There were 37 patients in the BPTB group and 28 patients in the HS group. For patients who did not undergo revision, significant differences were not found in visual analog score (p = 0.94), Lysholm score (p = 0.81), Kujala score (p = 0.85), or Tegner level (p = 0.81). No difference was detected in the rate of return to a level of activity at or above the same level prior to injury (p = 0.31). Significantly more patients in the BPTB group were graded 1a Lachman and negative pivot shift compared with the HS group (p < 0.001). There was a significant difference in mean side-to-side manual maximum arthrometric testing (p < 0.001). There were significantly fewer subsequent procedures and a lower rate of graft failures in the BPTB group. We detected no difference in subjective functional outcomes following ACL reconstruction. However, a higher failure rate in the HS reconstructions and greater laxity by arthrometric testing may indicate increased objective stability with the use of BPTB autograft in the young female patient population. The level of evidence for this article is (level III, retrospective cohort).

BACKGROUND: Patellar tendon rupture is rare in the general population. Typically, failure occurs proximally or at the mid-substance. Distal avulsion from the tibial tubercle in adults is rare and not well described in the orthopedic literature. METHODS: We present the largest series of patients with distal patellar tendon injury with associated multi-ligamentous disruption of the knee. A series of six patients with distal patellar tendon avulsion were identified at a single institution. The cases were reviewed and are presented. RESULTS: Each case of distal patellar tendon rupture was associated with high-energy trauma to the knee. There was multi-ligamentous disruption in all cases, associated tibial plateau fracture in one case, and a compartment syndrome diagnosed in another. We propose that distal patellar tendon avulsion is a distinct pathology of the extensor mechanism in healthy adults. When present, it should prompt clinicians to assess patients for occult knee dislocation, monitor their neurovascular status, and obtain an MRI to evaluate for associated multi-ligamentous injury. CONCLUSION: We propose a modification to the Schenk classification to include extensor mechanism injury to help guide steps of operative intervention.

OBJECTIVE: A new closed reduction technique for anterior glenohumeral dislocations and tuberosity fracture dislocations is introduced. METHODS: Forty-one consecutive patients with an acute anterior glenohumeral dislocation or tuberosity fracture dislocation underwent closed reduction by an orthopaedic surgeon employing this new method. RESULTS: Closed reduction was successful in 88% of patients using the reduction maneuver. Associated fracture with glenohumeral dislocation did not influence the success rate of the reduction maneuver. An assistant was needed in 15% of cases. No complications related to the reduction maneuver were noted amongst the cohort. CONCLUSION: This novel reduction technique is safe demonstrating excellent success rates both for anterior shoulder dislocations and tuberosity fracture-dislocations.

PURPOSE: To assess screw divergence when inserting an interference screw for a bone-patellar tendon-bone graft using an outside-in technique with a retrograde drill to create the femoral tunnel. METHODS: Ten cadaver specimens underwent anterior cruciate ligament reconstruction with a bone-patellar tendon-bone autograft, with 23-mm-deep tunnels created by a retrograde drill outside-in technique. Drilling angles were based on a previous study that established the optimal angles to recreate the anterior cruciate ligament footprint. To ensure that screw insertion angles matched the angle of socket drilling, a marking pen was used to transpose 2 lines on the skin of the anterior knee corresponding to the drill in both the coronal and axial planes with the knee held at 90 degrees of flexion. The femoral-sided bone plug was affixed with a 7 x 23 mm interference screw through an anteromedial portal. Computed tomography scans were used to calculate coronal and sagittal screw-tunnel divergence. RESULTS: The median screw divergence in the coronal plane was 2.79 degrees , with a range of 1.1 degrees to 17.2 degrees . Of 10 specimens, 8 had no divergence (0 degrees to 5 degrees ), 0 screws were between 5 degrees and 10 degrees , 1 screw was between 10 degrees and 15 degrees , and 1 screw was between 15 degrees and 20 degrees . The 95% confidence interval was 3.73 degrees to 11.69 degrees . No screws had >/=20 degrees of divergence. In the sagittal plane, the median screw divergence was 5.68 degrees , with a range of 1.2 degrees to 18.7 degrees . Five specimens had no divergence (0 degrees to 5 degrees ), 3 screws were between 5 degrees and 10 degrees , 0 screws were between 10 degrees and 15 degrees , and 2 screws were between 15 degrees and 20 degrees of divergence. The 95% confidence interval was 3.73 degrees to 11.69 degrees . No screws had >/=20 degrees of divergence. CONCLUSIONS: The results of this study showed that 80% of screws diverted less than 5 degrees in the coronal plane. In the sagittal plane, only 50% of screws were found to have divergence of 5 degrees or less. No screw in either plane had divergence of greater than or equal to 20 degrees . CLINICAL RELEVANCE: When using a retrograde drill, a skin marking technique is a useful aid in placing interference screws with acceptable angles of divergence when using an inside-out technique.

In an effort to better restore normal joint function and kinematics, recent emphasis has been placed on surgical techniques that provide a more anatomic reconstruction of the anterior cruciate ligament (ACL). With femoral tunnel placement shown to play a vital role in the biomechanics, stability, and clinical outcomes after ACL reconstruction, approaches that better approximate the ACL's native femoral origin have been adopted. The independent anteromedial portal technique is thought to better position the femoral tunnel within the native ACL footprint and leave the graft more posteroinferior on the wall of the lateral femoral condyle than the more traditional transtibial approach. This article outlines the surgical technique for an anteromedial portal ACL reconstruction with a tibialis anterior allograft fixed with the Mitek Femoral and Tibial Intrafix sheath and screw system (DePuy Synthes, Raynham, MA).

PURPOSE: To determine when patients recover the ability to safely operate the brakes of an automobile after a right-knee anterior cruciate ligament reconstruction (ACLR). METHODS: A computerized driving simulator was used to determine braking ability after an isolated right-knee ACLR. Thirty healthy volunteers were tested at 1 visit to determine normal mean values, and 27 treatment subjects were tested at 1 week, 3 weeks, and 6 weeks after ACLR. Nine study subjects were treated with a patella tendon (BPTB) autograft, 9 were treated with a hamstring (HS) autograft, and 9 were treated with a tibialis anterior (TA) allograft. The driving simulator collected data on brake reaction time (BRT), brake travel time (BTT), and total brake time (TBT) at each visit. RESULTS: The control group generated a BRT of 725 milliseconds, BTT of 2.87 seconds, and TBT of 3.59 seconds. At week 1, all treatment patients had significant differences compared with controls for BRT, BTT, and TBT, except the BTT of the HS group. At week 3, all measures for the allograft group and the BRT for both autograft groups were no longer significantly different compared with controls, but significant differences were found for TBT in the HS and BPTB groups (P = .03, P = .01). At week 6, BRT, BTT, and TBT were no longer significantly different for either the HS group or BPTB group. CONCLUSIONS: Patients who underwent a right-knee ACLR with a TA allograft regained normal braking times by week 3 postoperatively. In contrast, those treated with a BPTB or HS autograft demonstrated significantly delayed braking times at 3 weeks but returned to normal braking ability by week 6. Those treated with an autograft had an earlier return of normalized BRT than BTT. LEVEL OF EVIDENCE: Level III, case-control series.

Articular cartilage is a specialized tissue that lines the surface of joints. Injuries to articular cartilage pose challenges due to poor healing potential. Focal cartilage defects are typically the result of high impact or repetitive loads to the articular surface. They tend to occur in the younger, active population and have been shown to cause swelling, pain, and joint dysfunction. Although the natural history of these lesions has never been definitively elucidated in the literature, clinical experience suggests that if left untreated, these lesions will demonstrate an inability to heal and may lead to prolonged increased articular peak stresses, which in turn may lead to pain and significant limitations in the future. The purpose of the present review is to provide the most current treatment options for these injuries and review the literature supporting their use.