The American Journal of Sports Medicine

Background: Overuse lower limb injury is common in incidence and morbidity. Many risk factors, gait related and biomechanical, have been identified, although little conclusive evidence has been found in terms of injury prevention to date.

Hypothesis: Orthoses, as produced by proprietary software interpretation of plantar pressures, are able to reduce injury rates in an “at risk” military population.

Study Design: Randomized controlled trial; Level of evidence, 1.

Methods: Four hundred military officer trainees were assessed by means of pressure plate recording of their contact foot pressures during walking. Participants were risk assessed and randomized to receive or not receive customized orthoses using the D3D system. Both cohorts were followed up for injury through their basic training at the 7-week point.

Results: The orthotic intervention group sustained 21 injuries in total (1 injury per 4666 hours of training), whereas the control group sustained 61 injuries in total (1 injury per 1600 hours of training) (P < .0001), thereby demonstrating an absolute risk reduction of 0.49 from use of the orthoses (P < .0001, chi square; confidence interval, 1.7, 2.4).

Conclusion: In this military trainee population, orthoses were effective in the prevention of overuse lower limb injury. This is the first study to identify a positive preventive role of orthoses.

Background: Animal studies have shown that local application of platelet-rich plasma (PRP) stimulates tendon repair. Preliminary results from a retrospective case series have shown faster return to sports.

Hypothesis: Autologous PRP stimulates healing of acute Achilles tendon ruptures.

Study Design: Randomized controlled trial; Level of evidence, 2.

Methods: Thirty patients were recruited consecutively. During surgery, tantalum beads were implanted in the Achilles tendon proximal and distal to the rupture. Before skin suture, randomization was performed, and 16 patients were injected with 10mL PRP (10 times higher platelet concentration than peripheral blood) whereas 14 were not. With 3-dimensional radiographs (roentgen stereophotogrammetric analysis; RSA), the distance between the beads was measured at 7, 19, and 52 weeks while the patient resisted different dorsal flexion moments over the ankle joint, thereby estimating tendon strain per load. An estimate of elasticity modulus was calculated using callus dimensions from computed tomography. At 1 year, functional outcome was evaluated, including the heel raise index and Achilles Tendon Total Rupture Score. The primary effect variables were elasticity modulus at 7 weeks and heel raise index at 1 year.

Results: The mechanical variables showed a large degree of variation between patients that could not be explained by measuring error. No significant group differences in elasticity modulus could be shown. There was no significant difference in heel raise index. The Achilles Tendon Total Rupture Score was lower in the PRP group, suggesting a detrimental effect. There was a correlation between the elasticity modulus at 7 and 19 weeks and the heel raise index at 52 weeks.

Conclusion: The results suggest that PRP is not useful for treatment of Achilles tendon ruptures. The variation in elasticity modulus provides biologically relevant information, although it is unclear how early biomechanics is connected to late clinical results.

Background: While single-bundle anterior cruciate ligament reconstruction reduces anterior-posterior laxity, studies have demonstrated residual rotational instability. Improved pivot-shift results have been shown with the double-bundle graft; however, no study has compared rotational laxity outcome of these surgical techniques in vivo under quantified, isolated torsional loading.

Hypothesis: The anterior cruciate ligament–deficient knee exhibits greater rotational laxity than the contralateral uninjured knee. The double-bundle reconstruction restores rotational joint stability to a greater extent than single-bundle surgery.

Study Design: Controlled laboratory study.

Methods: Rotational laxity of 32 patients with unilateral anterior cruciate ligament injury was assessed in both knees at full extension and 30° of flexion using a magnetic resonance imaging–compatible torsional loading device. Patients were randomly allocated either a single- or double-bundle reconstruction and reassessed 5 months after surgery.

Results: The anterior cruciate ligament–deficient knees demonstrated greater laxity to internal rotational torque in the extended position, but not in the 30° flexed position. No significant differences in rotational laxity were found between single- and double-bundle reconstructions. In extension, excessive internal rotational laxity of injured compared with contralateral knees was reduced by anterior cruciate ligament reconstruction. The single-bundle reconstruction did not affect internal rotation compared with contralateral or preoperative groups. In response to internal rotational torque in the flexed knee position, the double-bundle reconstruction reduced laxity to 10.8° from the pre-operative value of 15.3° (P = .058); postoperative rotation was also significantly less than the contralateral laxity of 16.4° (P = .022).

Conclusion: The ruptured anterior cruciate ligament resulted in increased internal rotational laxity only in the extended position. The single-bundle reconstruction did not affect rotational restraint compared with contralateral or preoperative groups. The double-bundle procedure significantly reduced internal laxity in the flexed position when compared with normal.

Clinical Relevance: As the anterior cruciate ligament is not the primary restraint to rotation, its contribution to joint stability is limited under isolated torsional load. While the double-bundle graft demonstrates superior rotational constraint, this may be excessive for isolated anterior cruciate ligament rupture.

Background: In Switzerland, the national accident insurance company registered a total of 42 262 soccer injuries, resulting in costs of approximately 145 million Swiss francs (~US$130 million) in 2003. Research on injury prevention has shown that exercise-based programs can reduce the incidence of soccer injuries.

Purpose: This study was conducted to assess the implementation and effects of a countrywide campaign to reduce the incidence of soccer injuries in Swiss amateur players.

Study Design: Cohort study; Level of evidence, 3.

Methods: All coaches of the Schweizerischer Fussballverband (SFV) received information material and were instructed to implement the injury prevention program “The 11” in their training of amateur players. After the instruction, the coaches were asked to rate the quality and the feasibility of “The 11.” Before the start of the intervention and 4 years later, a representative sample of about 1000 Swiss soccer coaches were interviewed about the frequency and characteristics of injuries in their teams. Teams that did or did not practice “The 11” were compared with respect to the incidence of soccer injuries.

Results: A total of 5549 coaches for amateur players were instructed to perform “The 11” in the training with their teams. The ratings of the teaching session and the prevention program were overall very positive. In 2008, 80% of all SFV coaches knew the prevention campaign “The 11” and 57% performed the program or most parts of it. Teams performing “The 11” had an 11.5% lower incidence of match injuries and a 25.3% lower incidence of training injuries than other teams; noncontact injuries in particular were prevented by the program.

Conclusion: “The 11” was successfully implemented in a countrywide campaign and proved effective in reducing soccer injuries in amateur players. An effect of the prevention program was also observed in the population-based insurance data and health-care costs.

Background: The management of degenerative arthritis of the knee in the younger, active patient presents a challenge to the orthopaedic surgeon. Surgical treatment options include high tibial osteotomy (HTO), unicompartmental knee arthroplasty, and total knee arthroplasty.

Purpose: To examine the long-term survival of closing wedge HTO in a large series of patients up to 19 years after surgery.

Study Design: Case series; Level of evidence, 4.

Methods: Four hundred fifty-five consecutive patients underwent lateral closing wedge HTO for medial compartment osteoarthritis between 1990 and 2001. Between 2008 and 2009, patients were contacted via telephone, and assessment included incidence of further surgery, current body mass index (BMI), Oxford Knee Score, and British Orthopaedic Association Patient Satisfaction Scale. Failure was defined as the need for revision HTO or conversion to unicompartmental knee arthroplasty or total knee arthroplasty. Survival analysis was completed using the Kaplan-Meier method.

Results: High tibial osteotomy survival was determined in 413 patients (91%). Of the 397 remaining living patients at the time of final review, 394 (99%) were contacted for follow-up via telephone interview. The probability of survival for HTO at 5, 10, and 15 years was 95%, 79%, and 56%, respectively. Multivariate regression analysis showed that age under 50 years (P = .001), BMI less than 25 (P = .006), and ACL deficiency (P = .03) were associated with better odds of survival. Mean Oxford Knee Score was 40 of 48 (range, 17-48). Overall, 85% of patients were enthusiastic or satisfied, and 84% would undergo HTO again at a mean 12 years of follow-up.

Conclusion: High tibial osteotomy can be effective for periods longer than 15 years; however, results do deteriorate over time. Age less than 50 years, normal BMI, and ACL deficiency were independent factors associated with improved long-term survival of HTO.

Background: The value of arthroscopic revision shoulder stabilization after failed instability repair is still a matter of debate.

Hypothesis: Arthroscopic revision shoulder stabilization using suture anchors provides equivalent subjective and objective results compared with initial arthroscopic instability repair.

Study Design: Cohort study; Level of evidence, 3.

Methods: Twenty consecutive patients who underwent arthroscopic revision shoulder stabilization using suture anchors (group 2) were matched for age, gender, and handedness (dominant or nondominant) with 20 patients who had initial arthroscopic instability repair using the same technique (group 1). At the time of follow-up, a complete physical examination of both shoulders and evaluation with the Rowe score, Walch-Duplay score, Melbourne Instability Shoulder Score, Western Ontario Shoulder Instability Index, and the Subjective Shoulder Value were performed. In addition, standard radiographs (true AP and axillary views) were taken to evaluate signs of osteoarthritis.

Results: After a minimum follow-up of 24 months, no recurrent dislocations were observed in either group. The apprehension sign was positive in 2 cases of revision surgery (0 vs 2; P > .05). No significant differences in the Rowe score (89 vs 81.8 points) were found between groups 1 and 2 (P > .05). However, group 2 revealed significantly lower scores in the Walch-Duplay score (85.3 vs 75.5 points), Melbourne Instability Shoulder Score (90.2 vs 73.7 points), Western Ontario Shoulder Instability Index (89.8% vs 68.9%), and Subjective Shoulder Value (91.8% vs 69.2%) (P < .05). Signs of instability arthropathy were found more often in patients with arthroscopic revision surgery (2 vs 5; P > .05).

Conclusion: Arthroscopic revision shoulder stabilization is associated with a lower subjective outcome compared with initial arthroscopic stabilization. The objective results found in this study may overestimate the clinical outcome in this patient population.

Background: The increase in anterior laxity and slippage is greater with metal interference screw fixation of a hamstring anterior cruciate ligament (ACL) graft than a bone-patellar tendon-bone graft.

Hypothesis: When slippage-resistant fixation is used with a soft tissue graft, early recovery of function does not result in a clinically important increase in anterior laxity and slippage

Study Design: Case series; Level of evidence, 4.

Methods: Nineteen subjects were treated with a single-tunnel, single-looped, tibialis allograft with slippage-resistant, cortical fixation. An examiner, different from the treating surgeon, used stereophotogrammetric analysis to compute the increase in anterior laxity at a 150 N anterior force and slippage between the day of surgery and each monthly follow-up interval, and determined recovery of function and motion.

Results: Anterior laxity did not increase between the day of surgery and 1 year (P = .23). Total slippage plateaued after 1 month, but increased 1.5 mm between the day of surgery and 1 month (P < .05). Extension and flexion plateaued after 2 months (P < .0001 and P < .02, respectively); activity level (Tegner score) plateaued after 3 months (P < .05), function (Lysholm score) plateaued after 4 months (P < .002), and subjective satisfaction (International Knee Documentation Committee score) plateaued after 6 months (P < .02).

Conclusion: Early recovery of function after ACL reconstruction with a soft tissue allograft did not result in a clinically important increase in anterior laxity and slippage at 1 year. We believe the avoidance of an increase in anterior laxity was related to the use of a transtibial technique designed to place the femoral and tibial tunnels without roof and posterior cruciate ligament impingement, the use of cortical fixation devices designed to resist slippage, the use of an aseptically harvested fresh-frozen tibialis allograft that was not irradiated or chemically processed, and the use of a self-administered rehabilitation program designed to encourage an early return of motion and function.

Background: Few studies report the long-term results of anterior cruciate ligament rupture and single-incision endoscopic reconstructive surgery. Outcomes are often clouded by concomitant meniscal, chondral, or ligament injuries.

Purpose: To determine the 15-year outcomes of anterior cruciate ligament ruptures treated with endoscopic anterior cruciate ligament reconstruction using middle-third patellar tendon autograft.

Study Design: Case series; Level of evidence, 4.

Methods: Between January 1993 and April 1994, 333 consecutive patients underwent anterior cruciate ligament reconstruction. Patients with associated ligamentous injury requiring surgery, previous meniscectomy, or meniscal injury requiring more than one-third meniscectomy; chondral injury diagnosed at arthroscopy; and an abnormal contralateral knee were excluded. Ninety patients met the inclusion criteria. Outcomes included range of motion, Lachman and pivot-shift tests, instrumented ligament testing, single-legged hop test, Lysholm Knee Score, the International Knee Documentation Committee evaluation, and radiographic assessment.

Results: Thirty percent of patients had further anterior cruciate ligament injury. Twenty-four percent of patients (n = 22) sustained contralateral anterior cruciate ligament ruptures, and 8% (n = 7) ruptured the graft (P = .009). Graft rupture was associated with a graft inclination angle <17° (P = .02). Contralateral anterior cruciate ligament rupture was associated with age <18 years at time of primary injury (P = .001). All patients had normal or nearly normal (International Knee Documentation Committee evaluation) Lachman and instrumented testing, and 91% had a negative pivot-shift result. Seventy percent of patients had kneeling pain. Median subjective International Knee Documentation Committee evaluation was 91 of 100. Fifty-one percent of patients had radiographic evidence of osteoarthritis (41% grade B; 10% grade C).

Conclusion: Good results are maintained at 15 years after surgery with respect to ligamentous stability, subjective outcomes, and range of motion. Kneeling pain remains a significant problem. Concern remains regarding the incidence of further anterior cruciate ligament injury and the increasing number of patients with radiographic and clinical signs of osteoarthritis despite surgical stabilization.

Background: A posterior root tear of the medial meniscus disrupts hoop tension and causes extrusion of the meniscus, which results in progressive cartilage degeneration.

Purpose: To identify the structural integrity of healing after arthroscopic repair of a posterior root tear of the medial meniscus by second-look arthroscopy and to determine the clinical relevance of the findings.

Study Design: Case series; Level of evidence, 4.

Methods: From December 2006 to August 2008, 21 consecutive patients underwent arthroscopic pullout suture repair for a posterior root tear of the medial meniscus. Eleven were available for second-look arthroscopy evaluation (mean, 13.4 months; range, 10 to 22 months). The healing status of the repaired meniscus was classified as complete healing, lax healing, scar tissue healing, and failed healing. Chondral lesions were reviewed using arthroscopic photographs, and clinical evaluation was based on the Lysholm knee scores and the Hospital for Special Surgery scores.

Results: There was no case with complete healing. Five knees had lax healing (symptomatic in 2 and asymptomatic in 3); 4, scar tissue healing (asymptomatic in all 4); and 2, failed healing (symptomatic in 1 and asymptomatic in 1). Progression of the chondral lesion was found in 1 case. Mean Lysholm scores improved from 56.1 preoperatively (range, 41 to 71) to 83.0 at follow-up (range, 69 to 91; P = .003); mean Hospital for Special Surgery score also significantly increased, from 64.1 (range, 50 to 76) to 87.4 (range, 77 to 95; P = .003).

Conclusion: Complete healing was not observed in this retrospective case series of posterior horn meniscus repairs performed by 2 surgeons using a single technique. Further research is needed to clarify why all patients showed clinical improvement despite findings of incomplete or failed healing on second-look arthroscopy. Treatment modalities for managing posterior root tears of the medial meniscus require further investigation to determine their efficacy.

Nilsson-Helander K, Thomeé R, Grävare-Silbernagel K, Thomeé P, Faxén E, Eriksson BI, Karlsson J. The Achilles tendon Total Rupture Score (ATRS): development and validation. Am J Sports Med. 2007;35(3):421-426. (Original 10.1177/0363546506294856)

In the above article, there should not be a hyphen between the middle and surnames for Karen Grävare-Silbernagel. The correct citation format is as shown below:

Silbernagel KG

The updated article citation is:

Nilsson-Helander K, Thomeé R, Silbernagel KG, Thomeé P, Faxén E, Eriksson BI, Karlsson J. The Achilles tendon Total Rupture Score (ATRS): development and validation. Am J Sports Med. 2007;35(3):421-426.

Background: Current trends in anterior cruciate ligament reconstruction (ACLR) have been toward anatomical reconstruction that restores the normal size and location of the anterior cruciate ligament insertions and its 2 bundles, the posterolateral (PL) and anteromedial (AM) bundles. This has resulted in a more individualized approach to ACLR. Several studies have shown that the size of the anterior cruciate ligament insertion sites is variable; however, these studies are limited by use of relatively small sample sizes and cadaveric specimens.

Purpose: This study was undertaken to evaluate the in vivo size variability of the anterior cruciate ligament insertion sites and its AM and PL bundles during arthroscopy in a large series of patients and to correlate these findings with individuals’ physical characteristics (height, weight, and body mass index).

Study Design: Cross-sectional study; Level of evidence, 3.

Methods: In 137 patients undergoing ACLR during the first 6 months after injury, the femoral and tibial anterior cruciate ligament insertion sites and the 2 bundles were identified, marked with electrocautery, and measured with an arthroscopic ruler. Additionally, physical characteristics of the patients, including self-reported height, weight, and body mass index, were recorded.

Results: The tibial anterior cruciate ligament insertion site had a mean length of 17.0 ± 2.0 mm. The tibial AM bundle length was 9.1 ± 1.2 mm and the width was 9.2 ± 1.1 mm. The tibial PL bundle insertion site length averaged 7.4± 1.0 mm and the width averaged 7.0 ± 1.0 mm. The femoral insertion sites had a mean length of 16.5 ± 2.0 mm. The length of the femoral AM bundle insertion site averaged 9.2 ± 1.2 mm and the width averaged 8.9 ± 0.9 mm. The femoral PL bundle insertion site length averaged 7.1 ± 1.1 mm and the width averaged 6.9 ± 1.0 mm. There were significant positive correlations between patient height and weight (P < .05) with femoral and tibial anterior cruciate ligament insertion site length, tibial PL bundle insertion site length, femoral AM bundle insertion site length, and tibial AM bundle and PL bundle insertion site areas. However, the coefficients of determination values were low (1.0% to 19.4%).

Conclusion: There is a large variation in size of the anterior cruciate ligament insertion sites and the AM and PL bundles. Additionally, there are significant but weak correlations between the size of the insertions and height, weight, and body mass index of the individual patient.

Background: There are conflicting reports in the literature regarding the outcome of superior labral anterior posterior (SLAP) repairs in overhead athletes and a paucity of data demonstrating ability to return to prior level of competition.

Hypothesis: Kerlan-Jobe Orthopaedic Clinic shoulder and elbow score provides more accurate assessment of shoulder function and ability to return to previous level of athletic competition after SLAP lesion repair than does the conventional American Shoulder and Elbow Surgeons scoring system.

Study Design: Cohort study; Level of evidence, 3.

Methods: Twenty-three elite (collegiate or professional) overhead athletes who were more than 1-year status postarthroscopic repair of type II SLAP lesions were evaluated using both the Kerlan-Jobe Orthopaedic Clinic shoulder and elbow score and American Shoulder and Elbow Surgeons score. P values were computed using the analysis of variance model. Postoperative American Shoulder and Elbow Surgeons and Kerlan-Jobe Orthopaedic Clinic scores from subjects were compared with control values obtained from a healthy athletic cohort; the relationship between the scores was investigated using the linear regression model and assessed using Pearson correlations.

Results: At a mean 38-month follow-up, 13 athletes were playing pain free at the time of the questionnaire administration, 6 were playing with pain, and 4 were not playing because of pain. Regarding American Shoulder and Elbow Surgeons scores, 22 athletes (96%) had good-excellent scores, whereas 1 (4%) had a fair score. The Kerlan-Jobe Orthopaedic Clinic scores revealed 9 excellent (39%), 3 good (13%), 4 fair (17%), and 7 poor (30%) results for the same study group. Of the 23 patients, 13 (57%) had returned to their pain-free preinjury levels of competition at final follow-up. The inability to return to this level of competition correlated with the presence of a partial-thickness rotator cuff tear (P = .0059). The Kerlan-Jobe Orthopaedic Clinic demonstrated better overall accuracy (85%) than did the American Shoulder and Elbow Surgeons (70%) in evaluating return to pain-free preinjury levels.

Conclusion: Return to preinjury level of competition for elite overhead athletes after type II SLAP lesion repairs was 57%, despite high American Shoulder and Elbow Surgeons scores. Return to play status correlated with the presence of a partial-thickness rotator cuff tear. The Kerlan-Jobe Orthopaedic Clinic score, designed specifically for the evaluation of the overhead athlete, was a more accurate assessment tool than was the American Shoulder and Elbow Surgeons in this population of elite overhead athletes with SLAP tears.

Background: An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain.

Purpose: To compare isometric hip adduction and abduction strength on the dominant and nondominant side in injury-free soccer players.

Study Design: Cross-sectional study; Level of evidence, 3.

Methods: One hundred elite soccer players were included. Maximal unilateral isometric hip adduction and abduction strength on the dominant and nondominant side were measured with a handheld dynamometer, using a reliable test procedure.

Results: The dominant side was stronger than the nondominant side for both isometric hip adduction (2.45 ± 0.54 vs 2.37 ± 0.48 Nm/kg, P = .02) and hip abduction (2.35 ± 0.33 vs 2.25 ± 0.31 Nm/kg, P < .001), corresponding to a 3% and 4% difference, respectively. Isometric hip adduction was greater than isometric hip abduction for both the dominant (2.44 ± 0.53 vs 2.35 ± 0.33 Nm/kg, P = .04) and nondominant (2.37 ± 0.48 vs 2.26 ± 0.33 Nm/kg, P = .03) side. Isometric hip adduction/abduction ratio was not different between the dominant (1.04 ± 0.18) and nondominant (1.06 ± 0.17, P = .40) side. A post hoc analysis showed that isometric hip adduction/abduction ratio was significantly lower in players with groin pain during hip adduction testing compared with players with a pain-free test (0.80 ± 0.14, P < .001)

Conclusion: The marginal difference between the dominant and the nondominant side is within the measurement variation of the test procedure, and contralateral isometric hip adduction strength can therefore be used as a simple clinical reference point of full recovery of hip adduction muscle strength in soccer players. Furthermore, it is suggested that the ipsilateral hip adduction/abduction strength ratio is used as a guideline for evaluating hip adduction strength recovery in soccer players with bilateral groin problems.

Background: Several biomechanical studies have supported placing the femoral tunnel at a low position (10 or 2 o’clock) to achieve anterior and rotational knee stabilities after anterior cruciate ligament (ACL) reconstruction. However, no firm consensus has been reached regarding the merits and demerits of ACL reconstruction using a low femoral tunnel versus a high femoral tunnel (11 or 1 o’clock).

Hypothesis: A low femoral tunnel position during ACL reconstruction provides better intraoperative stability (especially, rotational stability) and clinical outcomes than does a high femoral tunnel position.

Study Design: Cohort study; Level of evidence 2.

Methods: Sixty-two patients who underwent ACL reconstruction were equally allocated to low and high femoral tunnel groups; 58 were followed up for a minimum of 2 years (29 in the each group). After reconstruction and using a navigation system, the authors compared intraoperative anterior, internal rotational, and external rotational stabilities at 0°, 30°, 60°, and 90° of knee flexion and compared clinical outcomes, including Lysholm knee scores, Tegner activity scores, Lachman and pivot-shift test findings, and radiographic stabilities at final follow-up visits.

Results: The low group showed significantly better intraoperative internal rotational stability at 0° and 30° of flexion but not at other angles (60° and 90°). Intraoperatively, no significant intergroup differences were found for anterior and external rotational stabilities at any flexion angle. Furthermore, clinical outcomes, including Lysholm knee and Tegner activity scores, showed no significant differences between the 2 groups at final follow-up visits (P > .05), and Lachman and pivot-shift test stability results and radiological stability data obtained at final follow-up were not significantly different between the 2 groups (P > .05).

Conclusion: The low femoral tunnel group showed better internal rotational stability at time zero during ACL reconstruction but similar anterior and external rotational stabilities. No significant differences were observed between the 2 groups in terms of clinical outcomes and stabilities after a minimum follow-up of 2 years.

Background: Several techniques have been described for reconstruction of the medial patellofemoral ligament (MPFL). The anatomical insertion of the MPFL has been defined; however, there are no reports describing the accuracy of femoral graft positioning assessed postoperatively.

Purpose: To analyze our femoral tunnel positioning for MPFL reconstruction in correlation with our clinical results.

Study Design: Case series; Level of evidence, 4.

Methods: The authors reported a prospective series of 29 MPFL reconstructions with a minimum follow-up of 24 months. The tunnel positioning analysis was performed using plain radiographs and magnetic resonance imaging at 1-year follow-up.

Results: Twenty-nine femoral tunnels were analyzed; 20 femoral tunnels (69%) were considered to be in good position on plain radiographs. On magnetic resonance imaging, the authors found 19 femoral tunnels (65%) in a proper location, 5 (17.5%) in a high position, and 5 in an anterior and/or high position.

Conclusion: The study highlights the difficulty of reproducible MPFL reconstruction. The surgical procedure continues to be improved and finding a reliable technique to anatomically place the graft remains challenging. Verifying femoral tunnel placement radiographically may be recommended during surgery.

Background: The medial patellofemoral ligament (MPFL) is the most important factor for stabilizing the patella and preventing lateral patellar dislocation. Medial patellofemoral ligament reconstruction is an accepted surgical technique to restore patellofemoral stability after lateral patellar dislocation. The authors recently developed a new anatomical MPFL reconstruction method using a cylindrical bone plug and grafted semitendinosus tendon at the anatomical femoral attachment site to mimic the native MPFL. This study evaluated the new technique for stabilizing recurrent patellar dislocation.

Hypothesis: This new MPFL reconstruction technique will improve knee symptoms and function with excellent clinical results.

Study Design: Case series; Level of evidence, 4.

Method: Thirty-one knees were evaluated from 29 cases of recurrent patellar dislocation that were surgically treated using the anatomical MPFL reconstruction technique. The average patient age was 22.2 years (range, 12-34 years); postsurgery follow-up was 2 to 5 years (average, 3.2 years). The patients were clinically evaluated based on the Kujala score, range of motion, and signs of apprehension. The Merchant view was used to measure congruence and tilting angles.

Results: Of the 31 knees, 30 showed good clinical results after surgery, while 1 patient showed remaining signs of apprehension. The Kujala score improved from an average of 64 points (range, 35-70) initially to an average of 94.5 points (range, 79-100) at the final follow-up. Range of motion improved for all patients, with an average knee extension of 0° ± 2° and knee flexion of 145° ± 3° at final follow-up. No patellar redislocation was reported. Radiological assessment indicated significant improvement to the congruence angle from 13° ± 4° before surgery to −5° ± 5° at the final follow-up, while the tilting angle went from 8° ± 7° before surgery to 7° ± 4° at the final follow-up.

Conclusion: This study demonstrated excellent results using the new procedure for recurrent dislocation of the patella, with instability in only 1 of 31 knees (3.2%).

Background: Chronic proximal hamstring tendinopathy is an overuse syndrome that is usually managed by nonoperative methods. Shockwave therapy has proved to be effective in many tendinopathies.

Hypothesis: Shockwave therapy may be more effective than other nonoperative treatments for chronic proximal hamstring tendinopathy.

Study Design: Randomized controlled clinical study; Level of evidence, 1.

Methods: Forty professional athletes with chronic proximal hamstring tendinopathy were enrolled between February 1, 2004, and September 30, 2006. Patients were randomly assigned to receive either shockwave therapy, consisting of 2500 impulses per session at a 0.18 mJ/mm² energy flux density without anesthesia, for 4 weeks (SWT group, n = 20), or traditional conservative treatment consisting of nonsteroidal anti-inflammatory drugs, physiotherapy, and an exercise program for hamstring muscles (TCT group, n = 20). Patients were evaluated before treatment, and 1 week and 3, 6, and 12 months after the end of treatment. The visual analog scale (VAS) score for pain and Nirschl phase rating scale (NPRS) were used as primary outcome measures.

Results: The patients were observed for a mean of 10.7 months (range, 1-12 months). Six patients were lost to follow-up because they underwent a surgical intervention: 3 (all in TCT group) were lost at 3 months; 2 (1 in each group), at 6 months; and 1 (in the TCT group), at 12 months. Primary follow-up was at 3 months after the beginning of treatment. The VAS scores in the SWT and TCT groups were 7 points before treatment (P = .84), and 2 points and 5 points, respectively, 3 months after treatment (P < .001). The NPRS scores in the SWT and TCT groups were 5 points in either group before treatment (P = .48), and 2 points and 6 points, respectively, 3 months after treatment (P < .001). At 3 months after treatment, 17 of the 20 patients (85%) in the SWT group and 2 of the 20 patients (10%) in the TCT group achieved a reduction of at least 50% in pain (P < .001). There were no serious complications in the SWT group.

Conclusion: Shockwave therapy is a safe and effective treatment for patients with chronic proximal hamstring tendinopathy.

Background: It is hypothesized that patients with patellofemoral pain syndrome (PFPS) have hip and core muscle weakness leading to dynamic malalignment of the lower extremity. Thus, hip strengthening is a common PFPS treatment approach.

Purpose: To determine changes in hip strength, core endurance, lower extremity biomechanics, and patient outcomes after proximally focused rehabilitation for PFPS patients.

Study Design: Case series; Level of evidence, 4.

Methods: Nineteen women (age, 22.68 ± 7.19 years; height, 1.64 ± 0.07 m; mass, 60.2 ± 7.35 kg) with PFPS participated in an 8-week program to strengthen the hip and core muscles and improve dynamic malalignment. Paired t tests were used to compare the dependent variables between prerehabilitation and postrehabilitation. The dependent variables were pain; functional ability; isometric hip abduction and external rotation strength; anterior, lateral, and posterior core endurance; joint range of motion (ROM; rearfoot eversion, knee abduction and internal rotation, and hip adduction and internal rotation); and peak internal joint moments (rearfoot inversion, knee abduction, and hip abduction and external rotation) during the stance phase of running.

Results: Significant improvements in pain, functional ability, lateral core endurance, hip abduction, and hip external rotation strength were observed. There was also a significant reduction in the knee abduction moment during running, although there were no significant changes in joint ROM.

Conclusion: An 8-week rehabilitation program focusing on strengthening and improving neuromuscular control of the hip and core musculature produces positive patient outcomes, improves hip and core muscle strength, and reduces the knee abduction moment, which is associated with developing PFPS.

Background: Lubricin and hyaluronic acid lubricate articular cartilage and prevent wear. Because lubricin loss occurs after anterior cruciate ligament injury, intra-articular lubricin injections may reduce cartilage damage in the anterior cruciate ligament–deficient knee.

Purpose: This study was conducted to determine if lubricin and/or hyaluronic acid supplementation will reduce cartilage damage in the anterior cruciate ligament–deficient knee.

Study Design: Controlled laboratory study.

Methods: Thirty-six male rats, 3 months old, underwent unilateral anterior cruciate ligament transection. They were randomized to 4 treatments: (1) saline (phosphate-buffered saline [PBS]), (2) hyaluronic acid (HA), (3) purified human lubricin (LUB), and (4) LUB and HA (LUB+HA). Intra-articular injections were given twice weekly for 4 weeks starting 1 week after surgery. Knees were harvested 1 week after the final injection. Radiographs of each limb and synovial fluid lavages were obtained at harvest. Histologic analysis was performed to assess cartilage damage using safranin O/fast green staining. Radiographs were scored for the severity of joint degeneration using the modified Kellgren-Lawrence scale. Synovial fluid levels of sulfated glycosaminoglycan, collagen II breakdown, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and lubricin were measured using enzyme-linked immunosorbent assay (ELISA).

Results: Treatment with LUB or LUB+HA significantly decreased radiographic and histologic scores of cartilage damage (P = .039 and P = .015, respectively) when compared with the PBS and HA conditions. There was no evidence of an effect of HA nor was the LUB effect HA-dependent, suggesting that the addition of HA did not further reduce damage. The synovial fluid of knees treated with LUB had significantly more lubricin in the synovial fluid at euthanasia, although there were no differences in the other cartilage metabolism biomarkers.

Conclusion: Supplemental intra-articular LUB reduced cartilage damage in the anterior cruciate ligament–transected rat knee 6 weeks after injury, while treatment with HA did not.

Clinical Relevance: Although longer term studies are needed, intra-articular supplementation (tribosupplementation) with lubricin after anterior cruciate ligament injury may protect the articular cartilage in the anterior cruciate ligament–injured knee.

Background: The posterolateral corner of the knee consists of static and dynamic stabilizing structures. Knee injuries often include the posterolateral structures. The popliteus muscle-tendon unit is known as the major dynamic stabilizer of the posterolateral corner.

Hypothesis: The dynamic stabilization of the posterolateral structures of the knee via the popliteus muscle-tendon unit during a squatting exercise follows a constant activation pattern.

Study Design: Controlled laboratory study.

Methods: Within the pilot study, 6 volunteers performed 2 exercises to verify the electrode position scheme and to analyze cross-talk. In the main study 2 static exercises (standing and standing with knees flexed 90°) and 2 dynamic exercises (isolated popliteus muscle activation and squats) were recorded in 17 volunteers. Electromyograms were obtained of the popliteus, medial and lateral gastrocnemius, and quadriceps muscles. Knee angle-related muscle activity was recorded.

Results: In the pilot study it was assumed that the chosen electrode position allowed selective measurement of popliteus muscle activity. In the main study the mean popliteus onset angle was 43° ± 14° of flexion; activity lasted through the reversal point of the squat to 58° ± 21° of flexion during extension movement. Popliteus activity during all testing cycles revealed that the activity in the standing position is the smallest. The highest activity was recorded during the squat and the popliteus muscle-tendon unit exercise.

Conclusion: This study demonstrates an activation pattern of the popliteus muscle-tendon unit with high interindividual differences in the onset angles. A constant activation during the reversal phase of the squatting exercise could be observed.

Clinical Relevance: Reconstructive procedures of the posterolateral structures often include reconstruction of the popliteus muscle-tendon unit. Reconstructive procedures are usually done in a static manner, thus not addressing the dynamic stabilizing structure in a true functional way. The findings of the current study may be a useful contribution to the ongoing discussion of this topic.

Background: Rotator cuff tendon-to-bone healing occurs by formation of a scar tissue interface after repair, which makes it prone to failure. Bone morphogenetic protein–13 (BMP-13) has been implicated in tendon and cartilage repair, and thus may augment rotator cuff repairs. The purpose of this study was to determine if the application of mesenchymal stem cells (MSCs) transduced with BMP-13 could improve regeneration of the tendon-bone insertion site in a rat rotator cuff repair model.

Hypothesis: Mesenchymal stem cells genetically modified to overexpress BMP-13 will improve rotator cuff healing based on histologic and biomechanical outcomes.

Study Design: Controlled laboratory study.

Methods: Sixty Lewis rats underwent unilateral detachment and repair of the supraspinatus tendon and 10 rats were used for MSC harvest. Animals were randomized into 2 groups (30 animals/group). The experimental group received 10⁶ MSCs transduced with adenoviral-mediated gene transfer of human BMP-13 (Ad-BMP-13). The second group received untransduced MSCs. Fifteen animals in each group were sacrificed at 2 and 4 weeks. At each time point, 12 animals were allocated for biomechanical testing, and 3 for histomorphometric analysis.

Results: There were no differences in the amount of new cartilage formation or collagen fiber organization between groups at either time point. There were also no differences in the biomechanical strength of the repairs, the cross-sectional area, peak stress at failure, or stiffness.

Conclusion: Application of MSCs genetically modified to overexpress BMP-13 did not improve healing in a rat model of rotator cuff repair.

Clinical Relevance: Further studies are needed to evaluate various growth factors and combinations of growth factors to determine the optimal factor for the biologic augmentation of rotator cuff repairs.

Background: The tissue-suture interface remains the most common site of failure in rotator cuff repairs. Improving stitch strengths may lead to lower failure rates.

Purpose: To compare biomechanical properties of 3 self-cinching stitches to the simple, mattress, modified Mason-Allen, and massive cuff stitches.

Study Design: Controlled laboratory study.

Methods: In sum, 336 sheep infraspinatus tendon grafts were randomized among 7 stitches. Each graft was cyclically loaded on a mechanical testing system from 5 to 30 N for 20 cycles and then loaded to failure. A mixed-effect multivariate regression model was used to test significance of suture type on cyclic elongation, peak-to-peak displacement, and ultimate load. Estimated means and standard deviations are reported from the regression model.

Results: Ultimate load for the simple stitch was significantly lower than for the other stitches. The lasso-loop and mattress stitch demonstrated similar ultimate loads. The double-cinch had a higher ultimate load than the lasso-loop or mattress stitch, although it was significantly weaker than the modified Mason-Allen, lasso-mattress, and massive cuff. The lasso-mattress had a superior ultimate load to the modified Mason-Allen and a similar ultimate load to the massive cuff stitch. One significant difference was found in cyclic elongation (1.42 mm for the simple to 1.80 mm for the double-cinch), and the cinching mechanism accounted for 0.2-mm higher elongation.

Conclusion: Self-cinching stitches lead to superior tissue-holding strength at the tissue-suture interface when compared with equivalent non-self-cinching stitches. Self-cinching stitches have greater elongation values. How these differences in cyclic elongation clinically influence gap formation at the repair site is unknown. The greater displacement seen in the self-cinching stitches is a potential concern because minimal gap formation is desired for a strong repair.

Clinical Relevance: The lasso-loop stitch is a stronger alternative to a simple stitch, and the double-cinch and lasso-mattress stitches are stronger alternatives to a mattress stitch.

Revision reconstruction of the anterior cruciate ligament (ACL) introduces several diagnostic and technical challenges in comparison with primary ACL reconstruction. With the increasing numbers of original reconstructions combined with the continued expectation of high-level athletic participation, revision ACL reconstruction is likely to become more frequent. The purpose of this article was to summarize the causes of failure and the evaluation of the patient with recurrent instability. A review of the literature regarding results after revision ACL reconstruction was performed to assist in the decision-making process and patient counseling. Good results can be obtained in terms of functional stability after revision reconstruction, but chondral and meniscal injury as well as unrecognized associated pathologic instability may play a role in diminished outcomes. In addition, a wide variety of surgical techniques are reviewed to address problems associated with tunnel malposition, widening, and pre-existing hardware.