Lutul D. Farrow

Comparison Between Rigid and Flexible Systems for Drilling the Femoral Tunnel Through an Anteromedial Portal in Anterior Cruciate Ligament Reconstruction

PURPOSE The purpose of this study was to compare the differences in femoral tunnel length and distance to the lateral anatomic structures when using standard and flexible guide pins for anterior cruciate ligament (ACL) femoral tunnel drilling through a medial portal. METHODS Using a medial arthroscopic portal in 10 cadaveric knees, we sequentially drilled straight and flexible guide pins into the center of the ACL femoral footprint using the same starting point. We recorded the interosseous length and distances to the peroneal nerve and the femoral origin of the lateral collateral ligament (LCL) for each pin. RESULTS The mean interosseous length was 43.5 mm for the flexible pin and 37.1 mm for the straight pin (P = .01). The mean distance to the peroneal nerve was 42.3 mm for the flexible pin and 37.8 mm for the straight pin (P = .33). The mean distance to the femoral origin of the LCL was 26.1 mm for the flexible pin and 13.4 mm for the straight pin (P = .003). CONCLUSIONS The use of commercially available flexible reamers and 42 degrees femoral guides results in longer femoral interosseous tunnel length than can be achieved with a straight guide pin. Femoral interosseous length consistently of 40 mm can be achieved with this technique and cannot be replicated with a rigid straight pin. This is advantageous for femoral tunnel drilling in an anatomic ACL reconstruction that uses suspensory fixation devices. There is minimal risk to the peroneal nerve and the femoral origin of the LCL unless lateral femoral wall blowout occurs. CLINICAL RELEVANCE Flexible pins allow longer femoral tunnels and safer distances from the LCL by use of a medial portal technique.

Quantitative Analysis of the Medial Ulnar Collateral Ligament Ulnar Footprint and Its Relationship to the Ulnar Sublime Tubercle

Background: The medial ulnar collateral ligament is the major soft tissue restraint to valgus displacement of the elbow. Currently, little has been published regarding the medial ulnar collateral ligament’s ulnar footprint. Hypothesis: The medial ulnar collateral ligament has a long attachment onto the ulna and the anatomy of the footprint is consistent. Study Design: Descriptive laboratory study. Methods: The authors studied the morphologic characteristics of the ulnar footprint of the medial ulnar collateral ligament in 10 fresh-frozen cadaveric specimens, 100 osseous specimens, and with 3-dimensional computed tomography in an additional 10 osseous specimens. They measured the length of the anterior band’s ulnar attachment and the entire ligament length. They also measured the length of the osseous ridge, which extends distally from the sublime tubercle in both osseous specimens and on computed tomography. Results: The mean length of the medial ulnar collateral ligament was 53.9 mm and the mean length of the ulnar soft tissue footprint was 29.2 mm. The authors identified an osseous ridge that extended distally from the sublime tubercle to just medial to the ulnar insertion of the brachialis muscle tendon. This osseous ridge was present in all osseous and fresh-frozen cadaveric specimens. The mean length of this osseous ridge was 24.5 mm. Conclusion: The medial ulnar collateral ligament has a long attachment along the proximal ulna. The ligament attaches to a previously undescribed ridge of bone located on the medial aspect of the proximal ulna, the medial ulnar collateral ligament ridge. This ridge is present in all skeletal specimens. Clinical Relevance: Injuries to the medial ulnar collateral ligament are common. Published success rates after reconstruction of the medial ulnar collateral ligament are highly variable. The present study illustrates how current reconstruction techniques fail to fully restore the true anatomy of the native ligament. Further studies are needed to investigate this issue.

The Relationship of the Medial Patellofemoral Ligament Attachment to the Distal Femoral Physis

Background: No published study has ever described the relationship of the medial patellofemoral ligament (MPFL) attachment to the distal femoral physis in skeletally immature cadaveric specimens. As such, there continues to be much confusion about this relationship, which is important when considering MPFL reconstruction in the skeletally immature patient. Hypothesis: The MPFL footprint is distal to the medial border of the distal femoral physis. Study Design: Descriptive laboratory study. Methods: Sixteen skeletally immature cadaveric specimens were used for this study. The average age of the specimens was 12 years (range, 10-15 years). The MPFL femoral attachment, adductor tubercle, and medial epicondyle were identified in all specimens, and the topography of the distal femoral physis was carefully described. Measurements were then taken of the distance from the medial aspect of the distal femoral physis to the MPFL femoral attachment and the horizontal distance from the MPFL femoral attachment to the point where a femoral tunnel would intersect the undulating femoral physis. All measurements were made with digital calipers. Results: The MPFL attachment was distal to the medial aspect of the femoral physis in all specimens. The MPFL attachment was an average of 8.5 mm distal to the medial aspect of the distal femoral physis. In the coronal plane, the undulating physis was 10.5 mm medial to the MPFL attachment. In all specimens, the undulations of the medial physis were concave directly posterior and lateral to the MPFL attachment and convex anterior to the MPFL attachment. Both the adductor tubercle and the medial epicondyle were also distal to the femoral physis in all specimens. Conclusion: This study has confirmed the findings of others, who have shown that the MPFL femoral attachment lies distal to the medial aspect of the distal femoral physis. In addition, the study findings show that the MPFL femoral attachment is in very close proximity to the distal femoral physis. Clinical Relevance: To facilitate anatomic MPFL reconstruction, Schottle et al described a radiographic method to identify the MPFL femoral attachment on lateral radiographs in skeletally mature patients. Because of the complex physeal anatomy, much confusion exists concerning whether an MPFL femoral tunnel can be placed safely in the pediatric patient. The findings of this study suggest that anatomic MPFL reconstruction may be accomplished with a tunnel angled distally and anteriorly to avoid injury to the distal femoral physis.

Radiographic Location of the Lateral Intercondylar Ridge Its Relationship to Blumensaat’s Line

Background The lateral intercondylar ridge (residents ridge) is considered to be an important landmark during anterior cruciate ligament reconstruction. Presently, no study exists describing the location of this vital landmark on plain radiographic images. Hypothesis Lateral intercondylar ridge location can be estimated on lateral plain film images. Study Design Descriptive laboratory study. Methods Lateral radiographic images were taken of 20 distal femora with metallic markers overlying the lateral intercondylar ridge. The length of Blumensaats line and the distance from the anterior extent of Blumensaats line to the point where the lateral intercondylar ridge intersects Blumensaats line were measured. The ratio of these measurements was then determined (Blumensaats-ridge ratio). The angle of the lateral intercondylar ridge with respect to Blumensaats line (Blumensaats-ridge angle) was also determined. Results The mean length of Blumensaats line was 32.1 mm (95% confidence interval, 31.0–33.2 mm). The mean distance from the anterior extent of Blumensaats line to the point where the lateral intercondylar ridge intersects Blumensaats line was 25.3 mm (95% confidence interval, 24.3–26.3 mm). The mean Blumensaats-ridge ratio was 0.79 (95% confidence interval, 0.77–0.81). The mean Blumensaats-ridge angle was 75.5° (95% confidence interval, 72.0°–79.1°). Conclusion The lateral intercondylar ridge intersects Blumensaats line at a point defined by multiplying the Blumensaats line length by 0.79. From this point, the ridge runs at a 75.5° angle with respect to Blumensaats line. Clinical Relevance Awareness of the radiographic location of the lateral intercondylar ridge may help confirm accurate tunnel placement when arthroscopic positioning is in doubt. Furthermore, femoral tunnel position can be quickly and accurately assessed in the outpatient setting in patients with unsatisfactory outcomes after anterior cruciate ligament reconstruction.

Radiographic Classification of the Femoral Intercondylar Notch Posterolateral Rim

PURPOSE The purpose of this study was to determine whether posterolateral rim morphology can be delineated on plain radiographic images. METHODS We obtained 20 femora from the Cleveland Museum of Natural History (10 each with distinct and indistinct posterolateral rims). Four blinded reviewers evaluated radiographic posterolateral rim morphology on lateral radiographs. The reviewers included a musculoskeletal radiologist, a fellowship-trained sports medicine surgeon, a pediatric orthopaedic surgeon, and a junior orthopaedic resident. Interobserver and intraobserver reliability was determined. RESULTS Radiographically, posterolateral rim morphology was classified into 2 types. Type 1 rims have a defined transition from Blumensaats line to the posterior femoral cortex. Type 2 rims have an indistinct transition. Interobserver reliability showed substantial agreement during the first (kappa = 0.65) and second (kappa = 0.70) sessions. Intraobserver reliability was nearly perfect, with kappa values ranging from 0.8 to 1.0. CONCLUSIONS It has been shown anatomically that the posterolateral rim has variable morphology. We have shown that posterolateral rim morphology can be delineated on lateral plain film images. Radiographic type 1 rims correlate with distinct posterolateral rim morphology. Radiographic type 2 rims correlate with indistinct posterolateral rim morphology. CLINICAL RELEVANCE For surgeons who reference the posterolateral rim for femoral tunnel placement during anterior cruciate ligament reconstruction, indistinct posterolateral rim morphology may result in errant tunnel placement. Improved awareness of posterolateral rim morphology preoperatively may help avoid technical errors with placement of the femoral tunnel.

Sonographic assessment of the medial ulnar collateral ligament distal ulnar attachment.

The purpose of this study was to determine whether the long distal attachment of the medial ulnar collateral ligament (MUCL) can be delineated on sonography.

Anterior Cruciate Ligament Graft Isometry Is Affected by the Orientation of the Femoral Tunnel

PURPOSE The purpose of this study was to compare anterior cruciate ligament (ACL) graft length and tension throughout knee range of motion with transtibial, anteromedial (AM) portal, and all-epiphyseal drilling techniques with suspensory and apical femoral fixation. METHODS The three different femoral tunnel drilling techniques using the same intra-articular starting point within the center of the femoral footprint were performed on fresh-frozen cadaveric specimens. All groups underwent standard tibial drilling in the center of the ACL tibial footprint. FiberWire (Arthrex Inc., Naples, FL) was used to simulate anatomic single bundle reconstructions. Changes in graft length and tension were measured at knee flexion angles of 0, 30, 60, 90, 120, and 135 degrees. RESULTS Graft length and tension decreased from 0 through 60 degrees and subsequently increased from 90 to 135 degrees for all groups. The transtibial, AM portal suspensory, and apical fixation groups were similar. However, the all-epiphyseal tunnel with suspensory fixation had a significantly increased change in length (90, 120, and 135 degrees) and tension (120 and 135 degrees). CONCLUSION Transtibial and AM portal suspensory fixation and apical fixation demonstrate similar changes in length and tension throughout knee range of motion. The all-epiphyseal tunnel with suspensory fixation was associated with greater length and tension changes at higher degrees of knee flexion. All techniques demonstrated decreased graft length and tension with knee flexion to 60 degrees after which they increased with further knee flexion. CLINICAL RELEVANCE ACL graft length and tension change throughout knee range of motion and also depend on femoral tunnel orientation and fixation type. The use of an all-epiphyseal tunnel with suspensory fixation should be studied further for evidence of graft elongation.

The Effect of Peroneus Brevis Tendon Anatomy on the Stability of Fractures at the Fifth Metatarsal Base

Background: Nonunion of classic Jones fractures has typically been attributed to the precarious vascular anatomy of the proximal fifth metatarsal. Despite this theory, the operative treatment of these fractures utilizes biomechanical solutions. The purpose of the present study was to evaluate the influence of the peroneus brevis (PB) tendon on the stability of fractures of the proximal fifth metatarsal. Methods: We utilized 5 matched pairs (10 specimens) of fresh-frozen cadaveric specimens. We used 2 loading conditions: (1) a simulated fracture distal to the PB insertion (Jones equivalent) and (2) a simulated fracture within the footprint of the PB insertion (avulsion equivalent). Following the creation of the fracture, each lower extremity was statically loaded through the Achilles and PB tendons. Our primary outcome measure was the degree of fracture diastasis with loading of the PB. Anteroposterior images with and without loading were obtained to evaluate fracture separation. We utilized a paired Student t test and the intraclass correlation coefficient (ICC) for all statistical analyses. Results: The average length of the PB footprint was 15.2 mm. The simulated Jones fractures demonstrated greater fracture widening following loading of the PB tendon compared to the simulated avulsion fractures. The simulated avulsion fractures widened 0.4 mm on loading compared to 1.1 mm of widening in the simulated Jones fractures (P = .02). Intraobserver reliability for all radiographic measurements showed substantial agreement (ICC = 0.91). Conclusion: The PB exerted a deforming force on the proximal fragment of simulated Jones fractures. This deforming force was less pronounced in the simulated avulsion fractures. The principal findings of this study were that proximal fifth metatarsal fractures distal to the PB insertion were significantly more unstable than more proximal fractures. Clinical Relevance: Our findings help support the notion that a mechanical component may contribute to the poor healing potential of Jones fractures secondary to deformation exerted by the PB tendon.

What Effect Does Anterior Cruciate Ligament Tibial Guide Orientation Have on Tibial Tunnel Length

PURPOSE To evaluate the effects of alteration in tibial guide pin insertion angle and external starting point on tibial tunnel length for anterior cruciate ligament (ACL) reconstruction. METHODS Ten cadaveric tibial specimens were used. One pin was placed at each of variable insertion angles (55°, 50°, and 45°) of the tibial targeting device aimed at the center of the tibial ACL footprint. These 3 pins started externally along the anterior border of the superficial medial collateral ligament. A fourth pin at 50° was placed at a different external tibial starting point 1.5 cm anterior to the anterior border of the superficial medial collateral ligament. The intraosseous length of each pin was measured. Statistic analyses were performed with the Kruskal-Wallis test, with significance set at P < .05. RESULTS The mean length for the 55° tibial tunnel was 50.3 mm (range, 42 to 56 mm); for the 50° tunnel, it was 48.9 mm (range, 44 to 55 mm); for the 50° anterior tunnel, it was 47.6 mm (range, 39 to 55 mm); and for the 45° tunnel, it was 47.3 mm (range, 41 to 52 mm). Changing the angle of the tibial guide did not significantly affect the length of the tibial tunnel (P = .18). Changing the external tibial starting point did not affect the length of the tibial tunnel (P = .39). CONCLUSIONS Changing the tibial guide angle between 45°, 50°, and 55° does not appreciably change tibial tunnel length. Moving the starting point anterior 1.5 cm toward the tibial tubercle also has no effect on the tibial tunnel length. The lack of significant changes in tunnel length with these interventions may reflect the associated changes that occur in proximal tibial morphometry with change in external tibial starting position. CLINICAL RELEVANCE Changing tibial tunnel length in ACL reconstruction likely requires more distalization of the external tibial starting point than is achieved simply by altering the tibial aiming guide angle by 10° or less.

Management of Posterior Cruciate Ligament Tibial Avulsion Injuries: A Systematic Review

Background: Tibial-sided avulsion injuries of the posterior cruciate ligament (PCL) generally require surgical intervention. No consensus exists concerning the optimal surgical treatment approach for these injuries. Purpose: To perform a systematic review investigating the open and arthroscopic surgical treatment modalities, outcomes, and complications of PCL tibial-sided bony avulsions. Study Design: Systematic review; Level of evidence, 4. Methods: The authors performed a systematic review of the literature utilizing PubMed and EMBASE from 1975 to present outlining open versus arthroscopic surgical repair of PCL bony avulsion injuries and comparing subjective and objective postoperative patient-reported outcomes, including Tegner, IKDC (International Knee Documentation Committee), and Lysholm scoring systems, as well as rates of patient complications. The quest was performed in June 2016, and searched terms included posterior cruciate ligament, PCL, bony, avulsion(s), tibial-sided, open, and arthroscopic. Inclusion criteria included English-language studies involving surgical fixation strategies for PCL tibial-sided bony avulsions. Exclusion criteria included non-English language, case studies/case series, and subject matter not pertaining to PCL bony avulsions. Results: Twenty-eight articles comprising 637 patients met the criteria and were included in the final review. PCL injuries with a tibial-sided avulsion were the result of motor vehicle accidents in 68.4% of patients, with 59.0% of these injuries resulting from motorcycle accidents. The arthroscopic group had better IKDC grade A scores (78.9%), indicating a normal knee postoperatively, as compared with the open group (65.9%). The postoperative Lysholm scores were similar between the groups, with a mean of 95.0 in the arthroscopic group and 92.8 in the open group. The arthroscopic group also reported 100% return to preinjury level of activity, compared with 86.2% in the open group. The most common complication in both groups was arthrofibrosis, which was reported more often in the arthroscopic group (0%-35%) versus the open treatment group (0%-25%). Conclusion: In patients with displaced tibial-sided PCL avulsion fractures treated operatively, surgical approaches render similar outcomes and risks. While the arthroscopic group had somewhat higher subjective and objective knee outcome scores, it demonstrated a slightly higher rate of arthrofibrosis. The clear advantage of the arthroscopic approach is that concomitant intra-articular injuries seen on preoperative magnetic resonance imaging, such as meniscal tears or osteochondral loose fragments, can be addressed at the time of the index operation.