Search

Synopsis The anterior cruciate ligament (ACL) is an important stabilizer of the knee against translational and rotational forces. The goal of anatomic reconstruction of the ACL-deficient knee is to re-create a stable knee that will allow for return to sport and prevent recurrent injury. Multiple graft options exist for ACL reconstruction, and each option has unique advantages and disadvantages. With appropriate patient selection, each graft can be utilized to optimize patient outcomes. Allograft options limit morbidity following ACL reconstruction, but care must be taken with surgical technique and postoperative rehabilitation to allow for graft incorporation. An understanding of the surgical technique and differences between graft options will allow the patient, surgeon, and physical therapist to maximize outcomes following ACL reconstruction. Level of Evidence Therapy, level 5. J Orthop Sports Phys Ther 2012;42(3):196–207, Epub 25 January 2012. doi:10.2519/jospt.2012.4083

We elucidated the gender and condylar effects on distal femur morphology (DFM) while evaluating a newly developed computational framework that enables fully automated analyses of DFM in an objectively defined sagittal plane. Ninety high-resolution CT-acquired distal femur models from 51 males and 39 females were analyzed. The models were accurately characterized (mean least-squares fitting residual

Background: Evidence suggests that single-bundle anterior cruciate ligament (ACL) reconstruction does not reliably prevent the development of knee osteoarthritis (OA). Purpose: This study was conducted to determine the overall prevalence of and risk factors for the development of radiographic knee OA after single-bundle ACL reconstruction. Study Design: Case control study; Level of evidence, 3. Methods: There were 249 individuals who had undergone primary single-bundle ACL reconstruction included in this retrospective cohort study. Follow-up radiographs were scored by a single orthopaedic surgery sports medicine fellow using the Kellgren-Lawrence (KL) scale to determine the degree of OA in the medial, lateral, and patellofemoral compartments. Radiographic OA of the involved knee was considered to be present if, compared with the noninvolved knee, there was at least a 2-grade difference in the KL score in at least 1 compartment or a 1-grade difference in at least 2 compartments. Predictors of OA that were explored included patient age, sex, body mass index (BMI), smoking status activity level, meniscectomy before or concurrent with ACL reconstruction, chondral injury present at the time of ACL reconstruction, graft type and source, tibial and femoral tunnel positions, need for revision, and length of follow-up. Univariable and stepwise multivariable logistic regressions were used to identify factors that were associated with radiographic knee OA. Results: Thirty-nine percent of the patients had radiographic OA an average of 7.8 years after surgery. Female sex, BMI, time from injury to surgery, medial and patellofemoral compartment chondrosis, prior medial or lateral meniscectomy, concurrent medial meniscectomy, and length of follow-up were associated with radiographic knee OA after ACL surgery. Stepwise multivariable logistic regression indicated that prior medial meniscectomy (95% confidence interval [CI], 1.39-6.85), grade 2 or greater medial chondrosis (95% CI, 1.27-6.73), length of follow-up (95% CI, 1.07-1.24), and BMI (overweight 95% CI, 1.08-3.84; obese 95% CI, 1.34-7.80) were the best set of predictors of knee OA. Conclusion: Despite reduced laxity and instability and improved activity and participation, individuals who have undergone ACL reconstruction are still at high risk for developing knee OA compared with the general population. The strongest predictors of knee OA after ACL reconstruction were obesity and grade 2 or greater chondrosis in the medial compartment. These results may aid in identifying patients at risk for OA after ACL reconstruction.

We performed this study to investigate the therapeutic role of vascular endothelial growth factor (VEGF) in medial collateral ligament (MCL) healing. Murine muscle derived stem cells (MDSCs) obtained via the preplate technique were retrovirally transduced to express: (1) VEGF and nLacZ (MDSC-VEGF), (2) soluble fms-like tyrosine kinase-1 (sFLT1, a VEGF-specific antagonist) and nLacZ (MDSC-sFLT1), and (3) nLacZ (MDSC-nLacZ). After transecting the MCL of immunodeficient rats, 5 × 105 cells of each of the transduction groups list above were transplanted into the MCL injury site. A control group was injected with phosphate-buffered saline (PBS) only. Immunohistochemical staining demonstrated that there were more Isolectin B4 and β-galactosidase double positive cells in the rats transplanted with MDSC-VEGF transduced cells than the other groups at week 1. Capillary density was significantly higher in the MDSC-VEGF group than the other groups at week 2; however, there were no significant differences in the biomechanical assessment between the MDSC-VEGF and MDSC-nLacZ groups. On the other hand, the MDSC-sFLT1 group revealed a lower capillary density than the other two groups and the functional ligament healing of the MDSC-sFLT1 group was significantly decreased compared to the other groups when assessed biomechanically. The findings of the present study suggest that angiogenesis plays a critical role in the healing process of injured MCL. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:627–633, 2012

Knee dislocations are relatively rare injuries but necessitate immediate and appropriate management. The prompt reduction of the dislocation and detailed evaluation of the neurovascular status of the limb are required to avoid limb-threatening complications. Although there remains considerable controversy over the ideal management of the multiple-ligamentous injured knee, here we present our preferred approach to the treatment of this injury. Important principles begin with a detailed and specific diagnosis, including the timing, grade, and associated injuries. Next, operative management should be performed only after thorough preoperative planning, timed electively, and performed within an inpatient setting. Although we still operate on complete grade III lateral corner and medial collateral ligament injuries acutely, delayed and/or staged surgery is acceptable in many cases of cruciate reconstruction. Generally speaking, the postoperative rehabilitation and return to work/sports is slower in these patients compared with those undergoing primary anterior cruciate ligament surgery. Nevertheless, adherence to strict surgical principles of anatomic repair/reconstruction of all ligamentous injuries can result in regaining adequate knee function. We present important considerations in surgical indications, timing, graft selections, anatomic reconstruction, and postoperative rehabilitation.

Background High tibial osteotomy is technically demanding. Risks include injury to the popliteal neurovascular bundle. The present goal was to further define this risk. Hypothesis The distance from the posterior tibia to the popliteal artery increases with increasing knee flexion. A saw angle perpendicular to the coronal plane can injure the popliteal artery. Study Design Descriptive laboratory study. Methods Seven fresh-frozen cadaveric lower extremities were used. Lateral radiographs at knee flexion angles of 90°, 60°, 45°, 30°, and 0° were taken to measure the distance from the anterior border of the popliteal artery to the posterior cortex of the tibia 5.0 mm and 2.0 cm below the joint line. After an opening wedge high tibial osteotomy was made, qualitative assessments were made of the depth of a saw blade inserted into the kerf and the relative encroachment of the saw blade on the popliteal artery. The interval through which the space anterior to the popliteus can be accessed was identified by gross dissection in all specimens. Results The distance from the posterior tibia to the popliteal artery increased with knee flexion. At 5.0 mm and 2.0 cm below the joint line, the mean distance at 90° was significantly greater than at all other angles. The popliteal artery could be injured by the oscillating saw at angles greater than 30° to the coronal plane. A protective device inserted anterior to the popliteus protects the neurovascular structures. Conclusion The popliteal artery is farthest from the posterior tibia at 90° of knee flexion. Saw angles greater than 30° from the coronal plane put the popliteal neurovasculature at risk of injury. Clinical Relevance To perform a safe osteotomy, the knee should be positioned in 90° of flexion with the saw angled less than 30° from the coronal plane. A protective device deep to the popliteus may protect against popliteal injury.

Background: Tears of the posterior root of the medial meniscus are becoming increasingly recognized. They can cause rapidly progressive arthritis, yet their biomechanical effects are not understood. The goal of this study was to determine the effects of posterior root tears of the medial meniscus and their repairs on tibiofemoral joint contact pressure and kinematics. Methods: Nine fresh-frozen cadaver knees were used. An axial load of 1000 N was applied with a custom testing jig at each of four knee-flexion angles: 0°, 30°, 60°, and 90°. The knees were otherwise unconstrained. Four conditions were tested: (1) intact, (2) a posterior root tear of the medial meniscus, (3) a repaired posterior root tear, and (4) a total medial meniscectomy. Fuji pressure-sensitive film was used to record the contact pressure and area for each testing condition. Kinematic data were obtained by using a robotic arm to record the position of the knees for each loading condition. Three-dimensional knee kinematics were analyzed with custom programs with use of previously described transformations. The measured variables were axial rotation, varus angulation, lateral translation, and anterior translation. Results: In the medial compartment, a posterior root tear of the medial meniscus caused a 25% increase in peak contact pressure compared with that found in the intact condition (p < 0.001). Repair restored the peak contact pressure to normal. No difference was detected between the peak contact pressure after the total medial meniscectomy and that associated with the root tear. The peak contact pressure in the lateral compartment after the total medial meniscectomy was up to 13% greater than that for all other conditions (p = 0.026). Significant increases in external rotation and lateral tibial translation, compared with the values in the intact knee, were observed in association with the posterior root tear (2.98° and 0.84 mm, respectively) and the meniscectomy (4.45° and 0.80 mm, respectively), and these increases were corrected by the repair. Conclusions: This study demonstrated significant changes in contact pressure and knee joint kinematics due to a posterior root tear of the medial meniscus. Root repair was successful in restoring joint biomechanics to within normal conditions. Clinical Relevance: This study provides a biomechanical rationale for surgical repair of posterior root tears of the medial meniscus. Clinical studies are required to define the appropriate patient population for, and to determine the clinical efficacy of, surgical treatment of this injury.

Purpose The purpose of this study was to identify preoperative and intraoperative factors that predict patient-oriented outcome as measured by the International Knee Documentation Committee (IKDC) Subjective Knee Form after anterior cruciate ligament (ACL) reconstruction. Methods We identified 402 subjects who had undergone primary single-bundle arthroscopic ACL reconstruction at a mean follow-up of 6.3 years (range, 2 to 15 years). The IKDC Subjective Knee Form was used to measure patient-reported outcome and was dichotomized as above or below the patient-specific age- and gender-matched population mean. Potential predictor variables included subject demographics, activity level before surgery, previous meniscectomy, and surgical variables. Multivariate logistic regression analysis was performed to identify the best subset of predictors for determining the likelihood that the IKDC score was better than the age- and gender-matched population mean. Results The dichotomized IKDC score was associated with body mass index (BMI), smoking status, education, previous medial meniscectomy, and medial chondrosis at the time of ACL reconstruction. The multivariate model containing only factors known before surgery included BMI and smoking status. Subjects with a BMI greater than 30 kg/m 2 had 0.35 times the odds of success as subjects with a normal BMI. Subjects who smoked had 0.36 times the odds of success as subjects who did not smoke. A model including medial chondrosis at the time of surgery had a slightly higher discriminatory power (area under the receiver operating characteristic curve, 0.65 v 0.61) and negative predictive value (71.4% v 60.0%) but similar positive predictive power (86.3% v 85.9%). Conclusions Lower patient-reported outcome after ACL reconstruction was strongly associated with obesity, smoking, and severe chondrosis at the time of surgery. Level of Evidence Level III, prognostic case-control study.

Reconstruction has become a common, safe, and very effective treatment for the ruptured anterior cruciate ligament. During the past 3 decades there have been numerous advancements in the treatment of this very common injury. Although there is still debate over the best treatment, here we present our preferred approach to anterior cruciate ligament reconstruction. The following describes a single-bundle reconstruction with the use of predominantly bone-patellar tendon-bone graft. The technique is based on the medial portal technique vs transtibial for femoral tunnel placement. In addition, a brief overview of augmentation technique is also described.

Posterolateral corner injury, an increasingly recognized entity, is commonly associated with concomitant ligament disruptions. Prompt recognition is critical for several reasons. Missed posterolateral corner injuries increase the failure rates for both anterior and posterior cruciate ligament reconstructions. Also, untreated posterolateral corner injuries lead to chronic disability. Acute (ie, immediate) surgical intervention results in superior outcomes compared with chronic (ie, late) reconstruction. Although no universal classification system has been adopted, attention to both varus and rotational stability is critical. Multiple options exist for posterolateral corner reconstruction, although recent trends have shifted toward anatomic reconstruction techniques.

A more complete biomechanical understanding of a combined posterior cruciate ligament and posterolateral corner knee reconstruction may help surgeons develop uniformly accepted clinical surgical techniques that restore normal anatomy and protect the knee from premature arthritic changes. We identified the in situ force patterns of the individual components of a combined double-bundle posterior cruciate ligament and posterolateral corner knee reconstruction. We tested 10 human cadaveric knees using a robotic testing system by sequentially cutting and reconstructing the posterior cruciate ligament and posterolateral corner. The knees were subjected to a 134-N posterior tibial load and 5-Nm external tibial torque. The posterior cruciate ligament was reconstructed with a double-bundle technique. The posterolateral corner reconstruction included reattaching the popliteus tendon to its femoral origin and reconstructing the popliteofibular ligament. The in situ forces in the anterolateral bundle were greater in the posterolateral corner-deficient state than in the posterolateral corner-reconstructed state at 30 degrees under the posterior tibial load and at 90 degrees under the external tibial torque. We observed no differences in the in situ forces between the anterolateral and posteromedial bundles under any loading condition. The popliteus tendon and popliteofibular ligament had similar in situ forces at all flexion angles. The data suggest the two bundles protect each other by functioning in a load-sharing, codominant fashion, with no component dominating at any flexion angle. We believe the findings support reconstructing both posterior cruciate ligament bundles and both posterolateral corner components.

The medial and lateral menisci possess different morphologic characteristics. The medial meniscus is crescent shaped and covers approximately one-third of the tibial plateau (Fig. 50.1). The medial meniscus root attachments are more anterior and posterior than those of the lateral meniscus, with the posterior root attachment adjacent to the posterior cruciate ligament (PCL) tibial insertion (Fig. 50.2). The medial meniscus also has a capsular attachment to the deep medial collateral ligament (MCL). In contrast, the lateral meniscus is semicircular in shape and covers greater than 50 % of the lateral tibial plateau [3] (Fig. 50.1). The anterior and posterior lateral meniscal root attachments are closely associated with the anterior cruciate ligament (ACL) [11, 19] (Fig. 50.2). Additional attachments of the lateral meniscus include the meniscofemoral ligaments of Wrisberg and Humphrey, the popliteomeniscal fascicles, and the coronary ligaments [9, 17]. The meniscofemoral ligaments contribute significantly to lateral meniscal stability as their cross-sectional area averages approximately 7–35 % of the cross-sectional area of the PCL [8]. Despite these attachments, the lateral meniscus is more mobile than the medial meniscus [3]. The semicircular shape of the lateral meniscus, with root attachments in close proximity to each other, differs from the crescent shape of the medial meniscus; this feature plays a role in possible transplantation techniques. In the procedure section of this chapter, a bone bridge technique for lateral meniscus transplantation will be discussed. However, a bone block technique is more difficult for medial meniscus transplantations, because the tibial root attachment sites are far apart. Further, a bone block technique for medial meniscus transplantation requires the removal of the medial tibial spine and a small portion of the articular cartilage of the medial tibial plateau.

The hamstrings musculature is a vital component of an intricate dynamic knee joint restraint mechanism. However, there is evidence based on research studies suggesting potential deficits to this complex mechanism due to donor site morbidity resulting from harvest of the ipsilateral semitendinosus and gracilis autograft (ISGA) for anterior cruciate ligament reconstruction (ACLR). The purpose of this retrospective research study was to investigate the effects of ISGA ACLR on neuromuscular and biomechanical performance during a single-leg vertical drop landing (VDL), a functional task and associated mechanism of anterior cruciate ligament disruption during physical activity. Fourteen physically active participants 22.5 +/- 4.1 years of age and 21.4 +/- 10.7 months post ISGA ACLR underwent bilateral neuromuscular, biomechanical and isokinetic strength and endurance evaluations matched to 14 control participants by sex, age, height and mass. Kinetic and kinematic data was obtained with 3-D motion analyses utilizing inverse dynamics while performing single-leg VDLs from a height of 30 cm. Integrated surface electromyography (SEMG) assessments of the quadriceps, hamstrings and gastrocnemius musculature were also conducted. Additionally, knee joint flexion strength (60 degrees s(-1)) and endurance (240 degrees s(-1)) measurements were tested via isokinetic dynamometry. No significant differences existed in hip and net summated extensor moments within or between groups. The ISGA ACLR participants recorded significantly decreased peak vertical ground reaction force (VGRF) landing upon the involved lower extremity compared to uninvolved (P = 0.028) and matched (P < 0.0001) controls. Participants having undergone ISGA ACLR also displayed greater peak hip joint flexion angles landing upon the involved lower extremity compared to uninvolved (P = 0.020) and matched (P = 0.026) controls at initial ground contact. The ISGA ACLR group furthermore exhibited increased peak hip joint flexion angles landing upon the involved lower extremity compared to uninvolved (P = 0.019) and matched (P = 0.007) controls at peak VGRF. Moreover, ISGA ALCR participants demonstrated greater peak knee (P = 0.005) and ankle (P = 0.017) joint flexion angles when landing upon the involved lower extremity compared to the matched control at peak VGRF. The ISGA ACLR group produced significantly greater reactive muscle activation of the vastus medialis (P = 0.013), vastus lateralis (P = 0.008) and medial hamstrings (P = 0.024) in the involved lower extremity compared to the matched control. The ISGA ACLR participants also exhibited greater preparatory (P = 0.033) and reactive (P = 0.022) co-contraction muscle activity of the quadriceps and hamstrings landing upon the involved lower extremity compared to the matched control. In addition, the ISGA ACLR group produced significantly less preparatory (P = 0.005) and reactive (P = 0.010) muscle activation of the gastrocnemius in the involved lower extremity compared to the uninvolved control. No significant differences were present in hamstrings muscular strength and endurance. Harvest of the ISGA for purposes of ACLR does not appear to result in significant neuromuscular, biomechanical or strength and endurance deficiencies due to donor site morbidity. However, it is evident that this specific population exhibits unique neuromuscular and biomechanical adaptations aimed to stabilize the knee previously subjected to ACL trauma and safeguard the ISGA ACLR joint. Co-contraction of quadriceps and hamstrings as well as inhibition of gastrocnemius muscle activation may serve to moderate excessive loads exposed to the intra-articular ISGA during single-leg VDLs. Furthermore, greater muscle activation of the hamstrings in conjunction with increased peak hip, knee and ankle joint flexion angles may assist in enhancing acceptance of VGRF transferred through the kinetic chain following single-leg VDLs.

Anterior cruciate ligament (ACL) injuries are the most common complete ligamentous injury to the knee. The optimal graft should be able to reproduce the anatomy and biomechanics of the ACL, be incorporated rapidly with strong initial fixation, and cause low graft-site morbidity. This article reviews the literature comparing the clinical outcomes following allograft and autograft ACL reconstruction and examines current issues regarding graft choice.

BackgroundPrevious studies have shown that increasing tibial slope can shift the resting position of the tibia anteriorly. As a result, sagittal osteotomies that alter slope have recently been proposed for treatment of posterior cruciate ligament (PCL) injuries.HypothesesIncreasing tibial slope with an osteotomy shifts the resting position anteriorly in a PCL-deficient knee, thereby partially reducing the posterior tibial “sag” associated with PCL injury. This shift in resting position from the increased slope causes a decrease in posterior tibial translation compared with the PCL-deficient knee in response to posterior tibial and axial compressive loads.Study DesignControlled laboratory study.MethodsThree knee conditions were tested with a robotic universal force-moment sensor testing system: intact, PCL-deficient, and PCL-deficient with increased tibial slope. Tibial slope was increased via a 5-mm anterior opening wedge osteotomy. Three external loading conditions were applied to each knee condition at 0°, 30°, 60°, 90°, and 120° of knee flexion: (1) 134-N anterior-posterior (A-P) tibial load, (2) 200-N axial compressive load, and (3) combined 134-N A-P and 200-N axial loads. For each loading condition, kinematics of the intact knee were recorded for the remaining 5 degrees of freedom (ie, A-P, medial-lateral, and proximal-distal translations, internal-external and varus-valgus rotations).ResultsPosterior cruciate ligament deficiency resulted in a posterior shift of the tibial resting position to 8.4 ± 2.6 mm at 90° compared with the intact knee. After osteotomy, tibial slope increased from 9.2° ± 1.0° in the intact knee to 13.8° ± 0.9°. This increase in slope reduced the posterior sag of the PCL-deficient knee, shifting the resting position anteriorly to 4.0 ± 2.0 mm at 90°. Under a 200-N axial compressive load with the osteotomy, an additional increase in anterior tibial translation to 2.7 ± 1.7 mm at 30° was observed. Under a 134-N A-P load, the osteotomy did not significantly affect total A-P translation when compared with the PCL-deficient knee. However, because of the anterior shift in resting position, there was a relative decrease in posterior tibial translation and increase in anterior tibial translation.ConclusionIncreasing tibial slope in a PCL-deficient knee reduces tibial sag by shifting the resting position of the tibia anteriorly. This sag is even further reduced when the knee is subjected to axial compressive loads.Clinical RelevanceThese data suggest that increasing tibial slope may be beneficial for patients with PCL-deficient knees.

Revision anterior cruciate ligament (ACL) reconstruction is a technically demanding procedure with outcomes that generally fail to reach those seen with primary ACL reconstruction. With most index procedures using autograft tissue, it is not uncommon for allograft tissue to be required for revision ACL reconstruction. Compared with autografts, allografts take longer to incorporate and lead to more episodes of instability. In this article, we describe ipsilateral iliotibial band tenodesis performed to augment use of bone-patellar tendon-bone allograft in revision ACL reconstruction. This technique adds rotational stability to protect the allograft tissue while it incorporates.

Background:Currently, placement of the tibial tunnel for arthroscopic transtibial posterior cruciate ligament (PCL) reconstruction relies on a limited arthroscopic view of the native insertion or the use of intraoperative imaging. No widely accepted method exists for intraoperative determination of PCL tibial tunnel placement, and current descriptions are cumbersome.Purpose:To identify the center of the PCL’s anatomic tibial insertion site as a percentage of the PCL facet length on a lateral radiograph of the knee so that it may be reliably located in the sagittal plane during surgical reconstruction.Study Design:Descriptive laboratory study.Methods:Twenty fresh-frozen cadaveric knees were dissected and the tibial insertions of the PCL were digitized with an optical tracing system. The digitized PCL footprints were mapped onto 3-dimensional computed tomography–acquired tibial models, and their center points were determined. A K-wire was then inserted into the center of the PCL’s tibial insertion under direct visualization, a direct lateral radiograph was obtained, and the center point was measured. The center locations for both methods were defined as a percentage of PCL facet length from anterior and proximal to posterior and distal, and intraobserver and interobserver reliability was tested with 4 different observers.Results:The average location of the PCL center on the 3-dimensional bone model method was 71.7% ± 5.6% along the PCL facet from anterior/proximal to posterior/distal. In the lateral radiographic method, the center of the PCL was at an average of 69.7% ± 4.9% of the facet length. There was no significant difference between the percentage measurements of the 2 methods ( P = .13). Interobserver reliability (κ = 0.57) and intraobserver reliability (κ = 0.71) were moderate to strong.Conclusion:Locating the center of the tibial PCL insertion with fluoroscopy at a point that is 70% of the PCL tibial facet length on a true lateral radiograph is a reliable method for locating the PCL tibial insertion.Clinical Relevance:The method described in this study enables clinicians to identify the tibial location of the PCL insertion, which must be accurately determined during PCL reconstruction.

INTRODUCTION The international exchange of German doctors especially in the US makes it important to compare both educational systems. The goal of this article is to discuss the differences and similarities between the German and US American curricula for Orthopaedic Sports Medicine. METHODS The German and US American curricula for Sports Medicine and their education and fellowship programs were compared. RESULTS The title 'Specialist for Sports Medicine' can be obtained in both countries. In Germany the curriculum is not speciality specific but offers a general Sports Medicine education that can be obtained through courses or fellowships. In the US this title can be obtained in two different ways, either through the American Board of Family Medicine (ABFM), or the American Board of Orthopaedic Surgery (ABOS) and their respective fellowship programs. DISCUSSION The Sports Medicine curriculum in Germany and in the US is different with a general Sports Medicine program in Germany and a specific Sports Orthopaedic program in the US.

Purpose: The purpose of our study was to determine the clinical outcomes following isolated lateral meniscal allograft transplantation. Methods: Thirty-two patients were retrospectively reviewed following isolated lateral meniscal allograft transplantation. Twenty-five were available for subjective follow-up, and 17 were available for a complete physical examination and postoperative radiographs. The average duration of follow-up was 3.3 years (range, 2 to 6 years), and the average age of the subjects was 30 years (range, 19 to 45 years). In all, 17 patients had bony fixation and 8 had suture fixation of the anterior and posterior horns of the meniscal allograft. Results: Ninety-six percent of patients believed that their overall function and activity level were improved following surgery. Short Form-36 (SF-36) physical and mental component summary scores for these subjects were higher than age- and sex-matched scores from the US population. Joint space narrowing of the transplanted lateral compartments was not significantly different when compared with the joint space narrowing of the lateral compartment of the contralateral knee. In addition, preoperative and postoperative radiographic joint space measurements of the involved lateral compartment were significantly associated with subjective assessment, symptoms, sports activity score, Lysholm score, and final International Knee Documentation Committee (IKDC) rating at latest follow-up. Finally, patients fixed with the bony technique had significantly better range of motion, according to IKDC criteria at latest follow-up, compared with the suture fixation group. Conclusions: Our results suggest that isolated meniscal allograft transplantation can be a beneficial procedure in properly selected symptomatic patients with a lateral meniscus–deficient knee. The data also suggest that earlier meniscal transplantation, before the onset of significant joint space narrowing, may result in improved outcomes. Finally, bony fixation may have a significant advantage over suture fixation, particularly with regard to knee range of motion. Level of Evidence: Level IV, therapeutic case series.

Background Single-injection femoral nerve block analgesia and spinal anesthesia have been associated with fewer postoperative nursing interventions and successful same-day discharge after anterior cruciate ligament reconstruction. In the current study, the authors prospectively determined the effect of continuous femoral nerve block on a numeric rating scale (NRS) of pain intensity with movement for 7 postoperative days. Methods Patients undergoing this surgery with no history of previous invasive surgery on the same knee were recruited for this study. After standardized spinal anesthesia, intravenous sedation, and perioperative multimodal analgesia, patients received a femoral nerve catheter with (1) saline bolus (30 ml) plus saline infusion (270 ml at 5 ml/h, placebo group); (2) levobupivacaine (0.25%) bolus with saline infusion (group I), or (3) levobupivacaine (0.25%) bolus and infusion (group II). Patients were surveyed preoperatively and on postoperative days 1-4 and 7 to determine NRS scores (scale 0-10). Results Data from 233 participants were analyzed. On days 1-2, 50% of placebo patients had NRS scores of 5 or above, whereas among group II patients, only 25% had scores of 5 or above (P < 0.001). In regression models for NRS scores during days 1-4, group II was the only factor predicting lower pain scores (odds ratios, 0.3-0.5; P = 0.001-0.03). Overall, patients with preoperative NRS scores greater than 2 were likely to report higher NRS scores during days 1-7 (odds ratios, 3.3-5.2; P < 0.001). Conclusions Femoral nerve block catheters reliably keep NRS scores below the moderate-to-severe pain threshold for the first 4 days after anterior cruciate ligament reconstruction.

Participants of contact sports are at risk for outbreaks of skin and soft tissue infection. Causes of reported outbreaks include Staphylococcus aureus, herpes simplex virus, Streptococcus pyogenes, and several fungi. Although once thought of solely as a nosocomial pathogen, methicillin-resistant Staphylococcus aureus has been identified as an emerging problem in the community, particularly in the athletic population. Despite a recent increase in reported outbreaks of community-acquired methicillin-resistant Staphylococcus aureus soft tissue infection in athletic teams, many sports medicine physicians are unfamiliar with the epidemiology of this pathogen. It is spread via person-to-person contact and is harbored within the anterior nares and on the skin of carriers. Outbreaks of community-acquired methicillin-resistant Staphylococcus aureus soft tissue infection are not treated by traditional β-lactam antibiotics, and they can be difficult to eradicate. Such infections have been associated with significant morbidity, with up to 70% of involved team members requiring hospitalization and intravenous antibiotics. A thorough understanding of community-acquired methicillin-resistant Staphylococcus aureus is essential for the sports medicine physician to properly identify, treat, and control infectious outbreaks.

Purpose: The purpose of this study was to evaluate the clinical outcomes after arthroscopic single-bundle posterior cruciate ligament (PCL) reconstruction in patients with isolated grade III PCL injuries. Type of Study: Retrospective review. Methods: Twenty-one patients who underwent an isolated arthroscopic single-bundle PCL reconstruction for the treatment of a grade III PCL injury between 1989 and 1998 were included in the study. There were 15 male and 6 female patients with an average age of 38 years (range, 20 to 62 years). The length of follow-up was 5.9 years (range, 2.6 to 11 years), and the average time from injury to surgery was 4.5 years (median, 1.3 years; range, 2 weeks to 25 years). All patients completed a subjective evaluation and 14 patients returned for a physical examination and radiographs. One patient underwent an acute reconstruction ( 3 months) reconstruction. The anterolateral bundle of the PCL was reconstructed using an Achilles tendon allograft passed through femoral and tibial bone tunnels. Results: The overall average Activities of Daily Living Scale (ADLS), Sports Activities Scale (SAS), and SF-36 scores were 79.3, 71.6, and 98 points, respectively. There was a significant difference identified when the ADLS (91.3 v 75.6) and the SAS (90.4 v 65.8) scores of the subacute/acute group were compared with those of the chronic reconstruction group. Using the International Knee Documentation Committee (IKDC) subjective assessment, 57% of the patients had normal/near normal knee function, and 62% had a normal/near normal activity level. The average extension and flexion losses were 1° and 5°, respectively. Instrumented laxity examination revealed that 62% had less than a 3-mm and 31% had a 3- to 5-mm side-to-side difference in corrected posterior displacement. Radiographs at follow-up showed that 75% had normal/near normal findings according to IKDC guidelines. Conclusions: The clinical outcomes after arthroscopic single-bundle PCL reconstruction in this study produced a satisfactory return of function and improvement in symptoms. All patients in this study had improved laxity of at least 1 grade. When compared with chronic reconstructions, acute reconstructions had statistically significant better ADLS and SAS scores. Level of Evidence: IV, case series.

The ideal graft for use in anterior cruciate ligament reconstruction should have structural and biomechanical properties similar to those of the native ligament, permit secure fixation and rapid biologic incorporation, and limit donor site morbidity. Many options have been clinically successful, but the ideal graft remains controversial. Graft choice depends on surgeon experience and preference, tissue availability, patient activity level, comorbidities, prior surgery, and patient preference. Patellar tendon autograft, the most widely used graft source, appears to be associated with an increased incidence of anterior knee pain compared with hamstring autograft. Use of hamstring autograft is increasing. Quadriceps tendon autograft is less popular but has shown excellent clinical results with low morbidity. Improved sterilization techniques have led to increased safety and availability of allograft, although allografts have a slower rate of incorporation than do most types of autograft. No graft has clearly been shown to provide a faster return to play. However, in general, patellar tendon autografts are preferable for high-performance athletes, and hamstring autografts and allografts have some relative advantages for lower-demand individuals. No current indications exist for synthetic ligaments.

Complete anterior cruciate ligament (ACL) ruptures can lead to recurrent knee instability, meniscal tears, and articular cartilage degeneration. ACL reconstruction typically has been performed using a single-bundle reconstruction technique that attempts to recreate the normal biomechanical properties of the native ACL. A critical review of the literature reveals that the success rates of single-bundle ACL reconstruction vary between 69% and 95%. The variability of the results may be attributed to the different techniques and styles of the individual surgeon, as there is variability in operative technique, fixation method, graft choice, and rehabilitation protocol. Our technique uses the medial portal technique and intraoperative radiographic analysis to more accurately recreate the anatomic insertion sites of the ACL femoral and tibial tunnels, respectively. Advantages of using the medial portal technique include the following: (1) femoral tunnel and tibial tunnels are placed independently of each other; (2) femoral tunnel is placed more anatomically on the ACL femoral insertion; (3) allows for easy preservation of any remaining ACL fibers (augmentation); and (4) tunnel placement is independent of graft type, fixation devices, or tunnel guides. We present our current technique for anatomic arthroscopic ACL reconstruction using a single-bundle graft.

BACKGROUND: The evaluation and management of knee dislocations remain variable and controversial. The purpose of this study was to describe our method of surgical treatment of knee dislocations with use of a standardized protocol and to report the clinical results. METHODS: Forty-seven consecutive patients presented with an occult (reduced) or grossly dislocated knee. Fourteen of these patients were not included in this series because of confounding variables: four had an open knee dislocation, five had vascular injury requiring repair, three were treated with external fixation, and two had associated injury. The remaining thirty-three patients underwent surgical treatment for the knee dislocation with our standard approach. Anatomical repair and/or replacement was performed with fresh-frozen allograft tissue. Thirty-one of the thirty-three patients returned for subjective and objective evaluation with use of four different knee-rating scales at a minimum of twenty-four months after the operation. RESULTS: Nineteen of the thirty-one patients were treated acutely (less than three weeks after the injury) and twelve, chronically. The mean Lysholm score was 91 points for the acutely reconstructed knees and 80 points for the chronically reconstructed knees. The Knee Outcome Survey Activities of Daily Living scores averaged 91 points for the acutely reconstructed knees and 84 points for the chronically reconstructed knees. The Knee Outcome Survey Sports Activity scores averaged 89 points for the acutely reconstructed knees and 69 points for the chronically reconstructed knees. According to the Meyers ratings, twenty-three patients had an excellent or good score and eight had a fair or poor score. Sixteen of the nineteen acutely reconstructed knees and seven of the twelve chronically reconstructed knees were given an excellent or good Meyers score. The average loss of extension was 1°, and the average loss of flexion was 12°. There was no difference in the range of motion between the acutely and chronically treated patients. Four acutely reconstructed knees required manipulation because of loss of flexion. Laxity tests demonstrated consistently improved stability in all patients, with more predictable results in the acutely treated patients. CONCLUSIONS: Surgical treatment of the knee dislocations in our series provided satisfactory subjective and objective outcomes at two to six years postoperatively. The patients who were treated acutely had higher subjective scores and better objective restoration of knee stability than did patients treated three weeks or more after the injury. Nearly all patients were able to perform daily activities with few problems. However, the ability of patients to return to high-demand sports and strenuous manual labor was less predictable.

Background Failure to address both components of a combined posterior cruciate ligament and posterolateral corner injury has been implicated as a reason for abnormal biomechanics and inferior clinical results. Hypothesis Combined double-bundle posterior cruciate ligament and posterolateral corner reconstruction restores the kinematics and in situ forces of the intact knee ligaments. Study Design Controlled laboratory study Methods Ten fresh-frozen human cadaveric knees were tested using a robotic testing system through sequential cutting and reconstructing of the posterior cruciate ligament and posterolateral corner. The knees were subjected to a 134-N posterior tibial load and a 5-N.m external tibial torque at multiple flexion angles. The double-bundle posterior cruciate ligament reconstruction was performed using Achilles and semitendinosus tendons. The posterolateral corner reconstruction consisted of reattaching the popliteus tendon to its femoral origin and reconstructing the popliteofibular ligament with a gracilis tendon. Results Under the posterior load, the combined reconstruction reduced posterior translation to within 1.2 - 1.5 mm of the intact knee. The in situ forces in the posterior cruciate ligament grafts were significantly less than those in the native posterior cruciate ligament at all angles except full extension. Conversely, the forces in the posterolateral corner grafts were significantly higher than those in the native structures at all angles. Under the external torque with the combined reconstruction, external rotation as well as in situ forces in the posterior cruciate ligament and posterolateral corner grafts were not different from the intact knee. Conclusions A combined posterior cruciate ligament and posterolateral corner reconstruction can restore intact knee kinematics at time zero. In situ forces in the intact posterior cruciate ligament and posterolateral corner were not reproduced by the reconstruction; however, the posterolateral corner reconstruction reduced the loads experienced by the posterior cruciate ligament grafts. Clinical Relevance By addressing both structures of this combined injury, this technique restores native kinematics under the applied loads at fixed flexion angles and demonstrates load sharing among the grafts creating a potentially protective effect against early failure of the posterior cruciate ligament grafts but with increased force in the posterolateral corner construct.

In the past several decades, there have been many advances in the diagnosis, surgical care, and rehabilitation of anterior cruciate ligament (ACL) injuries. However, there are few data in the literature as to whether these advances have successfully improved clinical outcomes following anterior cruciate ligament reconstruction. Thus, future research efforts should focus on the valid evaluation of clinical outcomes after ACL reconstruction. This article reviews the relevant clinical outcome measures for the evaluation of patients with anterior cruciate ligament injuries. The outcome evaluation of anterior cruciate ligament injuries should include measures of structure and function of the knee as well as measures of activity and participation of the individual. Measures of structure and function of the knee most directly related to injury of the ACL include measures of laxity and degeneration of the joint over time. Activity and participation can be measured by observing performance of the individual during a variety of activities or through the use of general and knee-specific a patient-reported measures of health related quality of life. When evaluating clinical outcomes following ACL injury, validated measures with established reliability and responsiveness must be used.

Background The tibial inlay technique for posterior cruciate ligament reconstruction has been proposed to provide a more anatomic reconstruction because it eliminates the sharp turn in the graft as it exits the proximal margin of the tibial tunnel in the transtibial technique. Hypothesis Reconstruction of the posterior cruciate ligament using the tibial inlay technique would more closely restore intact knee kinematics and in situ forces in the posterior cruciate ligament than would reconstruction using the transtibial technique. Methods Ten human cadaveric knees were tested in a controlled laboratory study. A robotic/universal force-moment sensor testing system was used to apply a 134-N posterior tibial load at 5 knee flexion angles: 0°, 30°, 60°, 90°, and 120°. Four knee conditions were tested: intact, posterior cruciate ligament–deficient, and the single-bundle tibial inlay reconstruction and transtibial posterior cruciate ligament reconstruction. Results Both reconstruction techniques restored posterior tibial translations to 1.7 to 2.1 mm of the intact knee, with no statistical differences between the techniques. In response to the posterior tibial load, in situ forces in both grafts were between 7 and 39 N less than those in the intact posterior cruciate ligament, with no significant differences between the grafts. Clinical Relevance The study suggests that either technique may be performed with similar biomechanical results at initial fixation under these loading conditions.

Background Anterior cruciate ligament reconstruction is a complex outpatient surgical procedure often associated with pain. Traditionally, the procedure is performed under general anesthesia and often requires the use of the PACU. Refractory pain and/or nausea/vomiting occasionally leads to an unplanned hospital admission. In this study, the authors examine the associations of nerve block analgesia for these patients and its associated reductions in PACU use, hospital admission, and hospital costs. Methods This was an observational, nonrandomized study in which existing data regarding patients' day-of-surgery outcomes were merged with hospital cost data. We reviewed a consecutive sample of 948 men and women who were in good health and underwent anterior cruciate ligament reconstruction in an outpatient surgery unit between July 1995 and June 1999. Results The use of nerve block analgesia was associated with reduced PACU admissions to 18% and decreased unplanned hospital admission rates from 17% to 4%. Multivariate linear regression analysis showed that patients bypassing the PACU had an associated hospital cost reduction of 12% (P = 0.0001), whereas patients who needed hospital admission had an associated hospital cost increase of 11% (P = 0.0003). Conclusions The use of nerve blocks for acute pain management in patients undergoing anterior cruciate ligament reconstruction is associated with PACU bypass and reliable same-day discharge. Although the cost savings for this one procedure are unlikely to generate sufficient cost savings via staffing reductions, extrapolating these results to a large volume of all types of invasive outpatient orthopedic procedures may have the potential to create significant hospital cost savings.

Background: Concomitant meniscal transplantation performed at the time of ligament surgery may help to protect the anterior cruciate ligament graft.Purpose: To determine the objective and subjective clinical outcomes after combined anterior cruciate ligament reconstruction and meniscal allograft transplantation.Study Design: Uncontrolled retrospective review.Methods: Twenty-eight patients who underwent anterior cruciate ligament reconstruction along with meniscal transplantation were retrospectively evaluated postoperatively at an average of 2.8 years (range, 1.8 to 5.6).Results: On the International Knee Documentation Committee overall subjective assessment, 86% had normal or nearly normal scores. The SF-36 physical and mental component summary scores were at higher levels than those of the patients' age- and sex-matched populations. Objectively, nearly 90% had normal or nearly normal Lachman and pivot shift test scores. The KT-1000 arthrometer testing at 30 pounds and maximum manual both demonstrated an average increased anterior translation of 1.5 mm compared with the contralateral knee. Joint space narrowing of the transplanted compartments was not significantly different from that of the contralateral knee.Conclusions: Meniscal transplantation with anterior cruciate ligament reconstruction can be a beneficial procedure in properly selected patients with either chronic anterior cruciate ligament insufficiency or failed anterior cruciate ligament surgery. Restoration of meniscal function may provide protection for the articular cartilage and improve joint stability.

Osteochondritis dissecans of the patella is a relatively rare condition. Treatment recommendations vary significantly from nonoperative treatment to surgical intervention. Surgical management varies from excision of the lesion to a variety of methods of stabilization. We present a case of patellar osteochondritis dissecans successfully treated with arthroscopically assisted retrograde fixation using fluoroscopic guidance. This surgical technique, which we describe in detail, avoids articular cartilage penetration and the need for an arthrotomy and allows for compression of the lesion with the hardware oriented perpendicular to the defect. It uses both fluoroscopic and arthroscopic imaging techniques for reduction and fixation.

Background Outpatient knee surgery has come to involve increasingly complex procedures. The authors present observational data from a nerve block algorithm designed for the care of outpatients undergoing knee surgery. The aim of this report is to demonstrate differences in pain and unplanned hospital admission associated with surgical complexity and nerve blocks used. Methods Day-of-surgery outcomes were studied for 1,200 consecutive outpatients undergoing routine arthroscopy or one of six complex outpatient knee procedures. Nerve blocks were administered on the basis of anticipated pain from open incisions in the femoral and sciatic nerve distributions. Regression analysis was used to determine factors associated with postoperative pain and unplanned hospital admissions, and patients were categorized as having received femoral and sciatic nerve blocks (FSB), femoral nerve block only (FNB), or no nerve blocks. Results Patients undergoing more complex (vs. less invasive) knee surgery were at greater risk for pain (P Conclusions For complex knee surgery, the use of FSB was associated with less pain; the use of FNB or FSB (vs. no block) was associated with fewer hospital admissions.

The menisci provide a vital role in load transmission across the knee joint as well as contribute to knee stability, particularly in the ACL-deficient knee. Loss of the meniscus, in part or in total, significantly alters joint function and predisposes the articular cartilage to degenerative changes, which has been well documented both clinically and radiographically. This study examined clinical and patient-reported outcomes following meniscal allograft transplantation with and without combined ACL reconstruction in a select group of 31 patients with complaints of pain and/or instability (34 meniscal allografts); 11 underwent isolated meniscal transplantation and 20 meniscal transplantation combined with ACL reconstruction. Bony fixation was performed with bone plugs for medial transplants and using a bone bridge for lateral transplants. All patients completed several knee-specific and general measures of health-related quality of life and underwent a comprehensive physical examination. Flexion weightbearing PA radiographs at latest follow-up were compared to those obtained preoperatively. Mean follow-up was 2.9 years (range 2-5.5 years). The Activities of Daily Living and Sports Activities Scale scores were 86+/-11 and 78+/-16, respectively, and the average Lysholm score was 84+/-14. There were no significant differences in these scores based upon which meniscus (medial or lateral) was transplanted, concurrent ACL reconstruction, or the degree of chondrosis at arthroscopy. SF-36 scores indicated that patients were functioning at a level similar to the age- and sex-matched population. Twenty-two patients stated they were greatly improved, 8 were somewhat improved, 1 was without change. All but one patient reported that knee function and level of activity were normal or nearly normal. The average loss of motion compared to the noninvolved side was 3 degrees for extension and 9 degrees for flexion. All but one patient had a negative or 1+ Lachman's test. The remaining patient had a 2+ Lachman's test. Assessment with the KT-1000 arthrometer revealed a side-to-side difference of 2 mm (range -2 mm to 7 mm). Average hop and vertical jump indices were both 85% of the contralateral extremity. No statistically significant joint space narrowing was observed by radiography over time. Meniscal allograft transplantation with and without combined ACL reconstruction in carefully selected patients with complaints of compartmental joint line pain and/or instability appears able to provide relief of symptoms and restore relatively high levels of function, particularly during activities of daily living.

Revision surgery for reconstruction of failed posterior cruciate and multiple-ligament-injured knees is a difficult problem for knee surgeons. The procedure is required much less commonly than revision anterior cruciate ligament (ACL) reconstructions. One of the key steps in managing this challenging problem is determining the cause of failure for the original procedure. Just as in the case of ACL failures, common causes of failure for posterior cruciate ligament (PCL) and multiple ligament injuries (MLI) reconstructions can be divided into three general categories: iatrogenic, biologic, and traumatic. Often unrecognized combined instability, improper graft technique, and abnormal bony architecture influence the success rate of primary and revision reconstructions. In devising a strategy for revision knee ligament surgery, thorough preoperative planning is essential to success.

The meniscal cartilage plays a vital role in maintaining normal knee function. This important structure providesshock absorption, stabilization, lubrication, proprioception, and load sharing to the knee joint. Although it has been shown that an anterior cruciate ligament (ACL) reconstruction can provide symptomatic pain relief in the arthritic knee, the results following ACL reconstruction in a medial meniscus-deficient knee are usually worse than when the medial meniscus is intact. Given these findings, meniscal allograft transplantation with concomitant ACL reconstruction have been performed to provide patients with a more stable and functional knee as well as to forestall the degenerative process. We report our indications, preoperative considerations, surgical technique, postoperative rehabilitation protocol, and results with meniscal allograft transplantation combined with ACL reconstruction. We believe that meniscal transplantation combined with ACL reconstruction, in appropriately selected patients with meniscus- and ACL-deficient knees, offers significant advantages that cannot be accomplished with either procedure alone. Although technically challenging, careful attention to the details outlined will help to avoid pitfalls and will maximize the opportunity for a successful outcome. Our results suggest that this procedure can predictably improve subjective measures of function and symptoms while objectively restoring stability and affording protection to the articular surfaces of the transplanted knee compartment.

Over the past thirty years, the subspecialty of sports medicine has evolved into a major component of the practice of orthopaedic surgery. Since its genesis in the early 1970s, sports medicine has evolved from the province of a small group of orthopaedists covering athletic teams into a major body of knowledge fueled by clinicians, scientists, and industry. Well-established educational curricula defining and prioritizing all areas of sports medicine now exist at the resident, fellowship, and subspecialty-society levels. The purpose of this article is to review and to put into perspective recent scientific and educational advancements in sports medicine. This overview is based on papers presented in 2000 at both the annual and subspecialty meetings of the American Orthopaedic Society for Sports Medicine (AOSSM), the Arthroscopy Association of North America (AANA), the Orthopaedic Research Society (ORS), and the American Academy of Orthopaedic Surgeons (AAOS). Papers published from September 1999 through August 2000 in the American Journal of Sports Medicine (six volumes), Arthroscopy (twelve volumes), and The Journal of Bone and Joint Surgery (twelve volumes) are reviewed, and their major contributions to orthopaedic sports medicine are summarized. This general overview of papers and presentations is followed by a summary of new developments in the study of the knee and shoulder as well as in other aspects of sports medicine, a discussion of emerging technologies in basic-science research, and an update on educational and socioeconomic issues. Between September 1999 and August 2000, research in orthopaedic sports medicine was featured in over 250 oral presentations at the annual and Specialty Day meetings of the American Orthopaedic Society for Sports Medicine, the Arthroscopy Association of North America, the Orthopaedic Research Society, and the American Academy of Orthopaedic Surgeons. Almost two-thirds of the studies focused on surgical techniques or clinical outcomes data, with just over a …

Background: It is commonly accepted that the anterolateral (AL) bundle of the posterior cruciate ligament (PCL) is tight in flexion and that the posteromedial (PM) bundle is tight in extension. However, a recent in vivo study showed that both bundles were tight in extension. Purpose: To investigate the effects of knee flexion angle, rotational torque, and anterior/posterior translational force on the end-to-end distance between the femoral and tibial insertion sites of each bundle of the PCL. Study Design: Descriptive laboratory study. Methods: Cadaveric knees (10 specimens) were mounted on a robotic system, and the relative positional data between the femur and tibia were acquired during passive flexion/extension, with an applied 5-N·m rotational torque and an applied 89-N translational force. The bony surface and PCL insertion data were acquired with a 3-dimensional scanner after gross dissection and were superimposed onto the positional data. The end-to-end distance between the 2 PCL insertion sites of the femur and tibia was measured. Results: The end-to-end distance increased from full extension to 90° for both the AL (9.2 ± 1.8 mm; from 30.0 to 39.2 mm) and PM bundles (5.8 ± 2.2 mm; from 32.0 to 37.7 mm). With an internal rotational torque, the end-to-end distance of the PM bundle increased significantly ( P < .05) at 0°, 30°, and 60° of knee flexion. Under a posterior translational force at 90° of knee flexion, the length of both bundles increased to their longest measurements (AM bundle: 40.6 ± 4.2 mm; PM bundle: 38.4 ± 3.8 mm). Conclusion: The end-to-end distance of the AL and PM bundles of the PCL increased in flexion, and this pattern was maintained during tests with posterior translational force. The PM bundle was more affected by the rotational torque than was the AL bundle. Clinical Relevance: Both bundles of the PCL may serve a greater functional role in flexion than in extension. The PM bundle might be more important for the control of rotation than the AL bundle. Posterior translation at 90° of knee flexion could be the most stressful condition for both bundles of the PCL, which may have implications for an injury mechanism.

Stress fractures of the fifth metatarsal are common injuries in athletes. They are high-risk stress fractures that frequently require surgery. These fractures have a unique classification system, and treatment options are largely dependent on classification as well as patient characteristics. The risk of delayed union and nonunion in these fractures is high if misdiagnosed or treated improperly.