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In August 2011, orthopaedic surgeons from more than 20 countries attended a summit on anatomic anterior cruciate ligament (ACL) reconstruction. The summit offered a unique opportunity to discuss current concepts, approaches, and techniques in the field of ACL reconstruction among leading surgeons in the field. Five panels (with 36 panellists) were conducted on key issues in ACL surgery: anatomic ACL reconstruction, rehabilitation and return to activity following anatomic ACL reconstruction, failure after ACL reconstruction, revision anatomic ACL reconstruction, and partial ACL injuries and ACL augmentation. Panellists’ responses were secondarily collected using an online survey. Thirty-six panellists (35 surgeons and 1 physical therapist) sat on at least one panel. Of the 35 surgeons surveyed, 22 reported performing “anatomic” ACL reconstructions. The preferred graft choice was hamstring tendon autograft (53.1 %) followed by bone-patellar tendon-bone autograft (22.8 %), allograft (13.5 %), and quadriceps tendon autograft (10.6 %). Patients generally returned to play after an average of 6 months, with return to full competition after an average of 8 months. ACL reconstruction “failure” was defined by 12 surgeons as instability and pathological laxity on examination, a need for revision, and/or evidence of tear on magnetic resonance imaging. The average percentage of patients meeting the criteria for “failure” was 8.2 %. These data summarize the results of five panels on anatomic ACL reconstruction. The most popular graft choice among surgeons for primary ACL reconstructions is hamstring tendon autograft, with allograft being used most frequently employed in revision cases. Nearly half of the surgeons surveyed performed both single- and double-bundle ACL reconstructions depending on certain criteria. Regardless of the technique regularly employed, there was unanimous support among surgeons for the use of “anatomic” reconstructions using bony and soft tissue remnant landmarks. V.

The use of platelet-rich plasma (PRP) is becoming more attractive given its favourable side effect profile and autologous nature, leading to rapid clinical adoption in the absence of high-level evidence. We are presenting three patients who developed a progression of patellar tendinitis following treatment, which to our knowledge is the first report of worsening of patellar tendinitis following PRP therapy. The records of three patients with symptom exacerbation of patellar tendinitis following treatment with PRP were reviewed. IRB exemption was obtained. Clinical and operative records, radiographs, and MR imaging were reviewed for all patients. Three patients reported to our clinic for a second opinion with symptoms of anterior knee pain consistent with patellar tendinitis. Each patient had previously been treated with PRP therapy due to prolonged symptoms. Clinical and radiological findings following treatment included patellar tendon thickening, worsening pain, discontinuation of athletic participation in all three patients, and osteolysis of the distal pole of the patella in one patient identified during surgical intervention. Growing interest in the use of autologous products for the management of chronic tendinopathies has led to widespread clinical implementation with minimal scientific support. It is tempting to apply a new treatment for management of a difficult clinical entity, especially when the risk/benefit ratio appears favourable. However, caution must be exercised as unexpected results may be encountered. Case reports, Level V.

The aim of this study was to examine clinical and patient-reported outcomes as well as return to sport in athletes younger than 25 following ACL reconstruction with either bone-patellar tendon-bone (BTB) or hamstring (HS) autografts using a matched-pairs case-control experimental design.Twenty-three matched pairs were obtained based on gender (57% women), age (18 ± 3 years BTB vs. 18 ± 3 HS), and length of follow-up (5 ± 2 years BTB vs. 4 ± 2 HS). Patients reported participating in very strenuous (soccer, basketball, etc.) or strenuous (skiing, tennis, etc.) sporting activity 4-7 times/week prior to their knee injury. Patient-reported outcomes included return to play data, the IKDC, SAS, ADLS, and SF-36 forms. Clinical outcomes included knee range of motion, laxity, and hop/jump testing.The majority of patients in both groups were able to participate in very strenuous or strenuous sporting activity 4-7 times per week following surgery [17 (74%) BTB vs. 16 (70%) HS]. However, only 13 (57%) of the BTB subjects and 10 (44%) of the HS patients were able to return to pre-injury activity levels (P = n.s.). HS patients showed higher ADLS (P 0.01) and SAS (P 0.01) scores, better restoration of extension (P 0.05), and less radiographic evidence of osteoarthritis (P 0.05).Hamstring and bone-patellar tendon-bone autografts allow approximately 70% of young athletes to return to some degree of strenuous or very strenuous sporting activity, while only approximately half of patients were able to return to their pre-injury sporting activity level. Hamstring grafts lead to better preservation of extension, higher patient-reported outcome scores, and less radiographic evidence of osteoarthritis.Therapeutic (case-control study) Level III.

The clinical implications of using irradiation to sterilize allograft bone-patellar tendon-bone (BPTB) remains unknown. The purpose of this study was to compare the clinical outcome of anterior cruciate ligament (ACL) reconstruction with irradiated allograft versus autograft BPTB. We hypothesized that patients undergoing ACL reconstruction with irradiated BPTB allograft would have no significant differences in patient-reported and objective parameters compared to those undergoing autograft BPTB reconstruction. Patients who underwent ACL reconstruction with either irradiated allograft or autograft BPTB from 1996 to 2002 were eligible for this study. One hundred and two patients (39 allograft, 63 autograft) met the study criteria and were available for follow-up. The BPTB allografts were obtained from a single tissue bank and were sterilized with 2.5 Mrad of irradiation prior to distribution. Participants completed the International Knee Documentation Committee (IKDC) subjective knee form and returned for physical and radiographic examinations, instrumented measurement of laxity, and functional testing. Patients were evaluated at an average follow-up of 4.2 years (range 1.8-8.4). Those undergoing allograft reconstruction were older (44+/-8.4 vs. 25.3+/-9.3 years, p0.001) and had a longer median time from injury to surgery (17.1 weeks vs. 9.7 weeks, p=0.04). There was no difference in IKDC Subjective Knee Scores between groups (86.7 allograft vs. 88.0 autograft, p=0.65). The average maximum manual KT-1000 side-to-side difference was 1.3 and 2.2 mm for allograft and autograft, respectively (p=0.04); however, after adjusting for age, this difference was no longer significant. 90.6% of the allograft and 82.8% of the autograft had normal/nearly normal overall IKDC physical examination rating (p=0.37). 66.7% of the allograft and 77.8% of the autograft returned to the same or more strenuous level of sports (p=0.25). Patients undergoing ACL reconstruction with irradiated allograft BPTB had similar clinical outcomes compared to those reconstructed with autograft BPTB. These data suggest that irradiation can be used to sterilize BPTB allograft without adversely affecting clinical outcome.

The objective of this study was to evaluate the effects of the biceps femoris tenodesis and popliteofibular ligament reconstruction on knee biomechanics. Ten human cadaveric knees were tested in the intact, posterolateral corner (PLC)-deficient, and PLC-reconstructed conditions using a robotic/universal force moment sensor testing system. The knees were subjected to: (1) a 134 N posterior tibial load, and (2) a 10 Nm external tibial torque applied to the tibia at full extension, 30 degrees and 90 degrees of flexion. External tibial rotation of the intact knee ranged from 18.3+/-4.6 degrees at full extension to 27.9+/-4.6 degrees at 30 degrees under the 10 Nm external tibial torque. These values increased after sectioning the PLC by 2.8 degrees -7.5 degrees at 30 degrees and 90 degrees respectively. After the popliteofibular ligament reconstruction, external tibial rotation values were not significantly different from those for the intact knee at any angle tested, while values following the biceps tenodesis were as much as 5.7 degrees greater than the intact knee. Under the 134 N posterior tibial load, there were minimal decreases in posterior tibial translation of up to 0.9 mm with the biceps tenodesis and up to 1.6 mm with the popliteofibular ligament reconstruction compared to the intact knee. The in situ forces in the biceps tenodesis were not significantly different than the intact PLC at full extension or 30 degrees, while the in situ forces in the popliteofibular graft were not significantly different at any flexion angle. Our data suggests that by restoring external tibial rotation the popliteofibular ligament reconstruction more closely reproduces the primary function of the PLC as compared to the biceps tenodesis.

In May 2000 over 50 surgeons representing 18 different countries and 5 continents assembled in Pittsburgh, Pennsylvania, USA, for the Eighth Panther Sports Medicine Symposium. Entitled “From Robotics to Gene Therapy: Sports Medicine in the New Millennium,” the symposium focused on both current perspectives and new and emerging technologies in the field of orthopedic sports medicine. Topics covered ranged from cruciate ligament reconstruction and meniscal transplantation to future directions and outcomes measurements in orthopedic sports medicine. The symposium also offered the unique opportunity of obtaining “a global perspective” on the current approaches used around the world for various sports related injuries. Eight global panels were held to provide an international viewpoint on topics such as cruciate ligament and posterolateral corner reconstruction, the dislocated knee, osteotomies about the knee, and return to play following ACL reconstruction. For each topic, each panelist gave a 6-min presentation describing his or her practice setting and patient profile, current techniques or approaches, and clinical outcomes. A 20-min question and answer session was then held (Fig.1). Finally, the session moderator presented the panel “consensus” in which the results were summarized and tabulated. The feedback that we received in response to these panels from both conferKNEE Knee Surg, Sports Traumatol, Arthrosc (2001) 9 :330–336

The objective of this study was to determine the effects of sectioning the posterolateral structures (PLS) on knee kinematics and in situ forces in the posterior cruciate ligament (PCL) in response to external and simulated muscle loads. Ten human cadaveric knees were tested using a robotic/universal force-moment sensor testing system. The knees were subjected to three loading conditions: (a) 134-N posterior tibial load, (b) 5-Nm external tibial torque, and (c) isolated hamstring load (40 N biceps/40 N semimembranosus). The knee kinematics and in situ forces in the PCL for the intact and PLS-deficient knee conditions were determined at full extension, 30 degrees, 60 degrees, 90 degrees, and 120 degrees of knee flexion. Under posterior tibial loading posterior tibial translation with PLS deficiency increased significantly at all flexion angles by 5.5+/-1.5 mm to 0.8+/-1.2 mm at full extension and 90 degrees, respectively. The corresponding in situ forces in the PCL increased by 17-19 N at full extension and 30 degrees of knee flexion. Under the external tibial torque, external tibial rotation increased significantly with PLS deficiency by 15.1+/-1.6 degrees at 30 degrees of flexion to 7.7+/-3.5 degrees at 90 degrees, with the in situ forces in the PCL increasing by 15-90 N. The largest increase occurred at 60 degrees to 120 degrees of knee flexion, representing forces two to six times of those in the intact knee. Under the simulated hamstring load, posterior tibial translation and external tibial and varus rotations also increased significantly at all knee flexion angles with PLS deficiency, but this was not so for the in situ forces in the PCL. Our data suggest that injuries to the PLS put the PCL and other soft tissue structures at increased risk of injury due to increased knee motion and the elevated in situ forces in the PCL.

Thirty patients having had anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) autograft and thirty patients having had ACL reconstruction with hamstring (HS) autograft were enrolled. All procedures were performed using an endoscopic technique with identical postoperative rehabilitation, such that the only variable was the type of graft and its fixation. Lateral and 45 degrees posteroanterior (PA) weightbearing radiographs were performed in each patient at 6-12 (mean 9) months postoperatively in the HS group and 9-22 (mean 13) months postoperatively in the PT group. The sclerotic margins of the tunnel were measured at the widest dimension of the tunnel by a single observer and were compared with the initially drilled tunnel size after correction for radiographic magnification. For the BPTB group, all bone plugs appeared to be incorporated radiographically. On the femoral side, the bone plug was incorporated at the roof of the intercondylar notch, such that no tunnel measurement could be made. Well-defined sclerotic margins were always present at the tibial and femoral tunnels for the HS group and at the tibial tunnel for the BPTB group. The mean percentage increase in tunnel size in the PA view was 9.7%+/-14.7% for the BPTB tibial tunnel, 20.9%+/-13.4% for the HS tibial tunnel, and 30.2%+/-17.2% for the HS femoral tunnel. The mean percentage increase in tunnel size in the lateral view was 14.4%+/-16.1% for the BPTB tibial tunnel, 25.5%+/-16.7% for the HS tibial tunnel, and 28.1%+/-14.7% for the HS femoral tunnel. The difference in HS and BPTB tibial tunnel expansion on both the PA and lateral views was statistically significant (P = 0.003 and P = 0.01, respectively). Inter-observer variability was excellent with an intra-class correlation coefficient of 0.92. Tunnel expansion was significantly greater following ACL reconstruction using HS autografts than in those using BPTB autografts. The points of fixation for the HS grafts are at a greater distance from the normal insertion site and biomechanical point of action of the ACL than the points of fixation for BPTB grafts. We believe that this greater distance creates a potentially larger force moment during graft cycling which may lead to greater expansion of bone tunnels.

The meniscofemoral ligaments (MFL) of 26 human cadaver knees were studied to determine their structural importance. The incidence of at least one MFL in each of the specimens studied was 100%, and 46% of the specimens had both MFL ligaments (Humphry and Wrisberg). Another 23% had a single Humphry ligament, and the remaining 31% had a single Wrisberg ligament. A laser micrometer system was used to measure cross-sectional shape and area. The average cross-sectional areas of the Humphry and Wrisberg ligaments were 7.8 +/- 4.7 mm2 and 6.7 +/- 4.1 mm2, respectively. In specimens with both a Humphry and Wrisberg ligament, the larger ligament area was on average 100% greater than the smaller ligament area. The average ratios of the cross sectional areas of Wrisberg and Humphry to that for the PCL within the same knee were 12.0% +/- 7.7% and 11.9% +/- 5.7%, respectively. The structural properties of the MFL bone-ligament-meniscus complex and the mechanical properties of the MFL midsubstance were determined by uniaxial tensile testing. The average stiffness, ultimate load, and energy absorbed at failure were, respectively, 49.0 +/- 18.4 N/mm, 297.4 +/- 141.4 N and 1125.4 +/- 735.8 N/mm. The tangent modulus between 4% and 7% strain was 355.1 +/- 234.0 MPa. Our findings suggest that the MFL is a significant biomechanical structure in the knee because of its size, stiffness, and strength.