Blood Flow Restriction Training Can Improve Peak Torque Strength in Chronic Atrophic Postoperative Quadriceps and Hamstrings Muscles.

PURPOSE: To report a prospective study of patients who underwent blood flow restriction training (BFRT) for marked quadriceps or hamstring muscle deficits after failure to respond to traditional rehabilitation after knee surgery. METHODS: The BFRT protocol consisted of 4 low resistance exercises (30% of 1 repetition maximum): leg press, knee extension, mini-squats, and hamstring curls with 60% to 80% limb arterial occlusion pressure. Knee peak isometric muscle torque (60° flexion) was measured on an isokinetic dynamometer. RESULTS: Twenty-seven patients (18 females, 9 males; mean age, 40.1 years) with severe quadriceps and/or hamstrings deficits were enrolled from April 2017 to January 2020. They had undergone a mean of 5.3 ± 3.5 months of outpatient therapy and 22 ± 10 supervised therapy visits and did not respond to traditional rehabilitation. Prior surgery included anterior cruciate ligament reconstruction, partial or total knee replacements, meniscus repairs, and others. All patients completed 9 BFRT sessions, and 14 patients completed 18 sessions. The mean quadriceps and hamstrings torque deficits before BFRT were 43% ± 16% and 38% ± 14%, respectively. After 9 BFRT sessions, statistically significant improvements were found in muscle peak torque deficits for the quadriceps (P = .003) and hamstring (P = .02), with continued improvements after 18 sessions (P = .004 and P = .002, respectively). After 18 BFRT sessions, the peak quadriceps and hamstring peak torques increased > 20% in 86% and 76% of the patients, respectively. The failure rate of achieving this improvement in peak quadriceps and hamstring torque after 18 BFRT sessions was 14% and 24%, respectively. CONCLUSIONS: BFRT produced statistically significant improvements in peak quadriceps and hamstring torque measurements after 9 and 18 sessions in a majority of patients with severe quadriceps and hamstring strength deficits that had failed to respond to many months of standard and monitored postoperative rehabilitation. LEVEL OF EVIDENCE: Level IV therapeutic case series.

Low-impact sports activities are feasible after meniscus transplantation: a systematic review.

PURPOSE: To determine sports activities achieved after meniscus transplantation and if associations exist between sports activity levels and transplant failure or progression of tibiofemoral osteoarthritis (OA). METHODS: A systematic search was performed using PubMed and Cochrane online databases. Inclusionary criteria were English language, clinical trials published from 1996 through May 2017, minimum 2 years of follow-up, and sports activity data reported. RESULTS: Twenty-eight studies were included in which 1521 menisci were implanted into 1497 patients. The mean age was 34.3 ± 6.7 years, and the mean follow-up was 5.0 ± 3.7 years. Details on sports activities were provided in 7 studies (285 patients) that reported 70-92% of patients returned to a wide variety of sports activities. Mean Tegner activity scores were reported in 24 investigations. The mean score was <5 in 58% of these studies, indicating many patients were participating in light recreational activities. There was no association between mean Tegner scores and transplant failure rates. A moderate correlation was found between failure rates and mean follow-up time (R = 0.63). The effect of sports activity levels on progression of tibiofemoral OA could not be determined because of limited data. Only two studies determined whether symptoms occurred during sports activities; these reported 1/38 (3%) and 5/69 (7%) patients had knee-related problems. CONCLUSIONS: It appeared that the majority of individuals returned to low-impact athletic activities after meniscus transplantation. The short-term follow-up did not allow for an analysis on the effect of return to high-impact activities on transplant failure rates or progression of OA. LEVEL OF EVIDENCE: IV.

A systematic review of the incidence and clinical significance of postoperative meniscus transplant extrusion.

PURPOSE: To determine the incidence and clinical significance of postoperative meniscus transplant extrusion. METHODS: A systematic search was performed using PubMed and Cochrane online databases. Inclusionary criteria were English language, clinical trials of meniscus transplantation published from 1984 to 2014, and meniscus extrusion measured on magnetic resonance imaging (MRI). RESULTS: Twenty-three studies were included, in which 814 menisci were implanted into 803 patients. MRIs were obtained from 2 days to 10 years postoperatively. Eighteen studies used fresh-frozen meniscus transplants implanted with bone (n = 612) or suture fixation (n = 116); four studies, cryopreserved transplants; and one, irradiated transplants. Three measurements assessed extrusion: absolute millimeters of extrusion (0-8.8 mm), relative percentage of extrusion (0-100%), and the percent of transplants that were extruded (0-100 %). Relationships between transplant extrusion and clinical rating scales, joint space narrowing on standing radiographs, and arthrosis progression were inconclusive. Non-anatomic placement of lateral meniscus transplants and suture fixation of medial and lateral transplants were associated with greater extrusion in two studies. CONCLUSIONS: Inconsistencies among studies prevent conclusions regarding the incidence and clinical significance of meniscus transplant extrusion. Even so, the short- to mid-term results were encouraging for knee function with daily activities and low rates of failure requiring transplant removal. A postoperative MRI showing more than 3-mm extrusion occurring in some studies suggested technique and/or implant sizing problems that required correction. Future studies should report absolute transplant extrusion, relative percent of extrusion, percent of transplant within the tibiofemoral compartment, and the percent of transplants that are extruded. LEVEL OF EVIDENCE: IV.

Neuromuscular retraining intervention programs: do they reduce noncontact anterior cruciate ligament injury rates in adolescent female athletes?

PURPOSE: The purpose of this study was to identify neuromuscular training intervention programs that significantly reduced the incidence of noncontact anterior cruciate ligament (ACL) injury rates in female adolescent athletes. METHODS: A systematic search of PubMed was conducted to determine the outcome of ACL neuromuscular retraining programs in a specific population. The inclusion criteria were English language, published from 1994-2013, original clinical trials, all evidence levels, female athletes aged 19 years or younger, and noncontact ACL injury incidence rates determined by athlete-exposures. RESULTS: Of 694 articles identified, 8 met the inclusion criteria. Three training programs significantly reduced noncontact ACL injury incidence rates in female adolescent athletes. These were the Sportsmetrics, Prevent Injury and Enhance Performance, and Knee Injury Prevention programs. The estimated number of athletes who needed to train to prevent 1 ACL injury in these 3 studies ranged from 70 to 98, and the relative risk reduction ranged from 75% to 100%. Five programs did not significantly reduce noncontact ACL injury incidence rates. The ACL injury incidence rates for control subjects were lower in these studies (0.03 to 0.08 per 1,000 athlete-exposures) than in those investigations that had a significant effect (0.21 to 0.49 per 1,000 athlete-exposures). There was wide variability among all programs in the frequency, duration, and timing of training; how training was conducted, supervised, or controlled; the components of the program; how exposure data were calculated; noncontact ACL injury incidence rates in the control groups; and compliance with training. CONCLUSIONS: Three ACL intervention programs successfully reduced noncontact ACL injury incidence rates in female adolescent athletes. Pooling of data of all ACL intervention programs is not recommended because of numerous methodologic differences among studies. LEVEL OF EVIDENCE: Level II, systematic review of Level I and II studies.

Clinical healing rates of meniscus repairs of tears in the central-third (red-white) zone.

PURPOSE: To determine the clinical healing rate of repairs of meniscus tears that extend into the central one-third region and the factors that affect the outcome. METHODS: A systematic search of PubMed was conducted to determine the outcome of meniscus repairs in the red-white (R/W) zone. Inclusion criteria were as follows: English language, clinical trials published from 1996 to 2013, R/W tears analyzed separately from tears in other zones, arthroscopic suture-based repairs, and all evidence levels. RESULTS: Of 344 articles identified, 23 met the inclusion criteria. There were 1,232 patients who had 1,326 meniscus repairs, of which 767 were in the R/W zone. Concurrent anterior cruciate ligament reconstruction was performed in 955 patients (78%). The mean age was 25 years, and the mean follow-up was 4 years. Evaluation criteria included clinical examination in 22 studies, follow-up arthroscopy in 15, magnetic resonance imaging in 6, weight-bearing radiographs in 3, and the International Knee Documentation Committee subjective score in 1. Overall, 637 (83%) of the repairs were considered clinically healed because no additional surgery was required and no obvious clinical meniscus symptoms were detected. This included 382 of 470 inside-out suture repairs (81%) and 255 of 297 all-inside suture repairs (86%). Twenty-two factors were assessed in 13 studies to determine their influence on the outcome, with varying results. Authors generally found that patient age, chronicity of injury, involved tibiofemoral compartment, gender, and concurrent anterior cruciate ligament reconstruction did not adversely affect the results. Insufficient data existed to assess the healing rates according to the type of meniscus tear except for single longitudinal tears. Complications were reported in 3% of the patients in this review. Long-term assessment of a chondroprotective effect of the repairs was conducted in only 2 studies. CONCLUSIONS: An acceptable midterm clinical healing rate was found for R/W meniscus repairs, supporting this procedure when appropriately indicated. Long-term studies assessing the chondroprotective effect in the involved tibiofemoral compartment using magnetic resonance imaging and radiographs are needed. LEVEL OF EVIDENCE: Level IV, systematic review of Level I-IV studies.

Advanced patellofemoral cartilage lesions in patients younger than 50 years of age: is there an ideal operative option?

PURPOSE: The purpose of this review was to determine if there is an ideal operation for large symptomatic articular cartilage lesions on the undersurface of the patella in young patients. METHODS: A systematic search of PubMed was conducted to determine the outcome of operations performed for large patellar lesions in young patients. Inclusionary criteria were English language, original clinical trials published from 1992 to 2012, patellar lesions 4 cm(2) or larger, mean patient age 50 years or younger, and all evidence levels. RESULTS: Of 991 articles identified, 18 met the inclusionary criteria, encompassing 840 knees in 828 patients. These included 613 knees that underwent autologous chondrocyte implantation (ACI) (11 studies), 193 knees that had patellofemoral arthroplasty (PFA) (5 studies), and 34 knees that underwent osteochondral allografting (OA) (2 studies). The mean patient age was 37.2 years and the mean follow-up was 6.2 years. Long-term follow-up (>10 years) was available in only 4 studies (2 PFA, 1 ACI, 1 OA). All studies except one were Level IV and none were randomized or had a control group. Twenty-one outcome instruments were used to determine knee function. When taking into account knees that either failed or had fair/poor function, the percentage of patients who failed to achieve a benefit averaged 22% after PFA and 53% after OA and ranged from 8% to 60% after ACI. In addition, all 3 procedures had unacceptable complication and reoperation rates. CONCLUSIONS: The combination of failure rates and fair/poor results indicated that all 3 procedures had unpredictable results. We concluded that a long-term beneficial effect might not occur in one of 3 ACI and PFA procedures and in 2 of 3 OA procedures. We were unable to determine an ideal surgical procedure to treat large symptomatic patellar lesions in patients 50 years or younger. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

A training program to improve neuromuscular and performance indices in female high school soccer players.

The purpose of this study was to determine if a sports-specific anterior cruciate ligament injury prevention training program could improve neuromuscular and performance indices in female high school soccer players. We combined components from a published knee ligament intervention program for jump and strength training with other exercises and drills to improve speed, agility, overall strength, and aerobic fitness. We hypothesized that this program would significantly improve neuromuscular and athletic performance indices in high school female soccer players. The supervised 6-week program was done 3 d·wk(-1) for 90-120 minutes per session on the soccer fields and weight room facilities in area high schools. In phase 1, 62 athletes underwent a video drop-jump test, t-test, 2 vertical jump tests, and a 37-m sprint test before and upon completion of the training program. In phase 2, 62 other athletes underwent a multistage fitness test before and after training. There were significant improvements in the mean absolute knee separation distance (p < 0.0001), mean absolute ankle separation distance (p < 0.0001), and mean normalized knee separation distance (p < 0.0001) on the drop-jump, indicating a more neutral lower limb alignment on landing. Significant improvements were found in the t-test (p < 0.0001), estimated maximal aerobic power (p < 0.0001), 37-m sprint test (p = 0.02), and in the 2-step approach vertical jump test (p = 0.04). This is the first study we are aware of that demonstrated the effectiveness of a knee ligament injury prevention training program in improving athletic performance indices in high school female soccer players. Future studies will determine if these findings improve athlete compliance and team participation in knee ligament injury intervention training.

Treatment of meniscus tears during anterior cruciate ligament reconstruction.

PURPOSE: To define the incidence of meniscectomy, meniscus repair, and meniscus tears left in situ during anterior cruciate ligament (ACL) reconstruction. METHODS: A systematic search of PubMed and 7 sports medicine journal databases was performed to determine the treatment of meniscus tears during ACL reconstruction. Inclusion criteria were English language, publication in the last 10 years, clinical trials, all evidence levels, and skeletally mature or immature knees. Exclusion criteria were revision ACL reconstruction, concomitant ligament reconstruction, and studies with exclusion or inclusion criteria regarding meniscus surgery during ACL reconstruction. RESULTS: Of 634 articles identified, 159 met the inclusion criteria, encompassing 19,531 patients. There were 11,711 meniscus tears; they were treated by meniscectomy in 65% (7,621 tears), treated by repair in 26% (3,022 tears), or left in situ in 9% (1,068 tears). Only 19 studies analyzed the treatment of meniscus tears according to the tibiofemoral compartment. These reported medial compartment tears were treated by meniscectomy in 63%, treated by repair in 27%, and left in situ in 9%. Lateral compartment tears were treated by meniscectomy in 71%, treated by repair in 14%, and left in situ in 14%. Only 24 studies identified the type of meniscus repair procedure performed. In 33 studies (21%) repair was performed more frequently than meniscectomy. CONCLUSIONS: Meniscectomy is performed 2 to 3 times more frequently than meniscus repair during ACL reconstruction. We were unable to analyze the effect of the location and type of meniscus tear, sex, age, or chronicity of injury on the treatment of meniscus tears. The number of potentially repairable meniscus tears that were treated by resection could not be identified. CLINICAL RELEVANCE: This study found that meniscectomy was performed in 65% of meniscus tears. This is concerning because studies have shown that, regardless of knee stability obtained after ACL reconstruction, meniscectomy accelerates degenerative joint changes. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

A training program to improve neuromuscular and performance indices in female high school basketball players.

The purpose of this study was to determine if a sports-specific training program could improve neuromuscular and performance indices in female high school basketball players. We combined components from a published anterior cruciate ligament injury prevention program for jump and strength training with other exercises and drills to improve speed, agility, overall strength, and aerobic conditioning. We hypothesized that this sports-specific training program would lead to significant improvements in neuromuscular and performance indices in high school female basketball players. Fifty-seven female athletes aged 14-17 years participated in the supervised 6-week program, 3 d·wk(-1) for approximately 90-120 minutes per session. The program was conducted on the basketball court and in weight room facilities in high schools. The athletes underwent a video drop-jump test, multistage fitness test, vertical jump test, and an 18-m sprint test before and upon completion of the training program. All the subjects attended at least 14 training sessions. After training, a significant increase was found in the mean estimated VO2max (p < 0.001), with 89% of the athletes improving this score. In the drop-jump video test, significant increases were found in the mean absolute knee separation distance (p < 0.0001) and in the mean normalized knee separation distance (p < 0.0001), indicating a more neutral lower limb alignment on landing. A significant improvement was found in the vertical jump test (p < 0.0001); however, the effect size was small (0.09). No improvement was noted in the sprint test. This program significantly improved lower limb alignment on a drop-jump test and estimated maximal aerobic power and may be implemented preseason or off-season in high school female basketball players.

Factors used to determine return to unrestricted sports activities after anterior cruciate ligament reconstruction.

PURPOSE: Anterior cruciate ligament (ACL) reconstruction is commonly performed in athletes, with the goal of return to sports activities. Unfortunately, this operation may fail, and the rates of either reinjuring an ACL-reconstructed knee or sustaining an ACL rupture to the contralateral knee range from 3% to 49%. One problem that exists is a lack of information and consensus regarding the appropriate criteria for releasing patients to unrestricted sports activities postoperatively. The purpose of this study was to determine the published criteria used to allow athletes to return to unrestricted sports activities after ACL reconstruction. METHODS: A systematic search was performed to identify the factors investigators used to determine when return to athletics was allowed after primary ACL reconstruction. Inclusion criteria were English language, publication within the last 10 years, clinical trial, all adult patients, primary ACL reconstruction, original research investigation, and minimum 12 months' follow-up. RESULTS: Of 716 studies identified, 264 met the inclusion criteria. Of these, 105 (40%) failed to provide any criteria for return to sports after ACL reconstruction. In 84 studies (32%) the amount of time postoperatively was the only criterion provided. In 40 studies (15%) the amount of time along with subjective criteria were given. Only 35 studies (13%) noted objective criteria required for return to athletics. These criteria included muscle strength or thigh circumference (28 studies), general knee examination (15 studies), single-leg hop tests (10 studies), Lachman rating (1 study), and validated questionnaires (1 study). CONCLUSIONS: The results of this systematic review show noteworthy problems and a lack of objective assessment before release to unrestricted sports activities. General recommendations are made for quantification of muscle strength, stability, neuromuscular control, and function in patients who desire to return to athletics after ACL reconstruction, with acknowledgment of the need for continued research in this area. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

Anterior cruciate ligament graft placement recommendations and bone-patellar tendon-bone graft indications to restore knee stability.

The anterior cruciate ligament (ACL) resists the combined abnormal motions of anterior tibial translation and internal tibial rotation that occur in the pivot-shift phenomenon. The placement of a single ACL graft high and proximal at the femoral attachment and posterior at the tibial attachment results in a vertical graft orientation. This graft position has a limited ability to provide rotational stability. A more oblique ACL graft orientation in the sagittal and coronal planes achieved from a central anatomic femoral and tibial location provides an orientation that is better in resisting the pivot-shift phenomenon. Tibial and femoral tunnels are drilled independently; transtibial drilling of the femoral tunnel is not recommended. The meticulous surgical technique for ACL reconstruction includes identifying the appropriate landmarks to achieve correct graft placement. There are insufficient experimental and clinical data to recommend the more complex double-bundle ACL graft technique over a central anatomic single graft in terms of restoring knee rotational stability. Allografts are used only in select knees for which autograft tissue is not available. The postoperative rehabilitation program takes into account the condition of the menisci and articular cartilage and associated reconstructive procedures.

Repair of complex and avascular meniscal tears and meniscal transplantation.

A functional meniscus is critical to the long-term health of the knee joint. The repair of meniscal tears that extend into the central avascular region requires understanding the appropriate indications, contraindications, surgical techniques, and postoperative rehabilitation protocols. An inside-out repair technique using multiple vertical divergent sutures with an accessory posteromedial or posterolateral incision is recommended for optimal stability. In young, active patients, the risk of repair failure and the need for revision are outweighed by the benefit of meniscal preservation. Although many meniscal tears are repairable, not all are salvageable, especially if considerable tissue damage has occurred. The goals of transplantation of human menisci are to restore partial load-bearing meniscal function, decrease patient symptoms, and provide chondroprotective effects. Clinical studies have shown that meniscal transplantation decreases tibiofemoral joint pain in the short term. The procedure remains in an evolving state with an unpredictable long-term outcome; however, most meniscal transplants gradually deteriorate, tear, or shrink in size over time, thereby losing the ability to provide function. The current goal is to provide short-term benefits to the patient until a superior meniscal transplant is clinically available.

A training program to improve neuromuscular indices in female high school volleyball players.

The purpose of this study was to determine if a sports-specific training program could improve neuromuscular indices in female high school volleyball players. We combined components from a previously published knee ligament injury prevention intervention program for jump and strength training with additional exercises and drills to improve speed, agility, overall strength, and aerobic conditioning. We hypothesized that this sports-specific training program would lead to significant improvements in neuromuscular indices in high school female volleyball players. Thirty-four athletes (age 14.5 years ± 1.0) participated in the supervised 6-week program, 3 d·wk(-1) for approximately 90-120 minutes per session. The program was conducted on the school's volleyball court and weight room facilities. The athletes underwent a video drop-jump test, multistage fitness test, vertical jump test, and sit-up test before and after training. A significant increase was found in the mean VO2max score (p < 0.001), where 73% of the athletes improved this score. A significant improvement was found in the sit-up test (p = 0.03) and in the vertical jump test (p = 0.05), where 68% of the athletes increased their scores. In the drop-jump video test, significant increases were found in both the mean absolute knee separation distance (p = 0.002) and in the mean normalized knee separation distance (p = 0.04), indicating improved lower limb alignment on landing. No athlete sustained an injury or developed an overuse syndrome during training. This program significantly improved lower limb alignment on a drop-jump test, abdominal strength, estimated maximal aerobic power, and vertical jump height and may be implemented in high school female volleyball programs.

Objective criteria for return to athletics after anterior cruciate ligament reconstruction and subsequent reinjury rates: a systematic review.

OBJECTIVE: To review anterior cruciate ligament (ACL) clinical studies to assess the objective functional criteria used to determine when patients can return to athletics postoperatively, and to determine the rates of reinjury to either knee when these criteria are applied. METHODS: A literature search was conducted using the Medline database. The inclusionary criteria were the English language, publication between April 2001 and April 2011, original clinical trials, all levels of evidence, primary ACL reconstruction, skeletal maturity, minimum 2 years of follow-up, and ≥1 objective test used to allow release to sports activities. The exclusionary criteria were revision ACL reconstructions or dislocated knees; studies that specifically excluded patients with ACL graft failure or reinjuries; major concomitant procedures such as high tibial osteotomy, meniscus allograft, other knee ligament reconstructions; and case reports, abstracts, review articles, and technical notes. RESULTS: Three objective criteria were used to allow release to sports activities. The most common were lower extremity muscle strength, followed by lower limb symmetry, and knee examination parameters of range of knee motion and effusion. Twelve studies listed 1 criterion for release to sports, 8 studies listed 2 criteria, and 1 study recommended 3 criteria. Failure rates of the ACL reconstructions ranged from 0% to 3% in 7 studies, from 4% to 6% in 6 studies, from 7% to 10% in 4 studies, and from 14% to 24% in 4 studies. There were no injuries in the contralateral ACL in 14 studies (67%); in the other 7 studies, contralateral injury was reported in 2% to 15% of patients. CONCLUSIONS: Few objective functional criteria are used to determine when patients return to unrestricted sports activities. Clinically feasible recommendations are made for measurement of muscle strength, lower limb symmetry, lower limb neuromuscular control, and ligament function in patients who desire to return to athletics after ACL reconstruction. Future studies are required to determine whether the demonstration of normal lower limb function before return to sports is effective in reducing reinjury rates.

A six-week neuromuscular training program for competitive junior tennis players.

This study evaluated the effectiveness of a tennis-specific training program on improving neuromuscular indices in competitive junior players. Tennis is a demanding sport because it requires speed, agility, explosive power, and aerobic conditioning along with the ability to react and anticipate quickly, and there are limited studies that evaluate these indices in young players after a multiweek training program. The program designed for this study implemented the essential components of a previously published neuromuscular training program and also included exercises designed to improve dynamic balance, agility, speed, and strength. Fifteen junior tennis players (10 girls, 5 boys; mean age, 13.0 +/- 1.5 years) who routinely participated in local tournaments and high-school teams participated in the 6-week supervised program. Training was conducted 3 times a week, with sessions lasting 1.5 hours that included a dynamic warm-up, plyometric and jump training, strength training (lower extremity, upper extremity, core), tennis-specific drills, and flexibility. After training, statistically significant improvements and large-to-moderate effect sizes were found in the single-leg triple crossover hop for both legs (p < 0.05), the baseline forehand (p = 0.006) and backhand (p = 0.0008) tests, the service line (p = 0.0009) test, the 1-court suicide (p < 0.0001), the 2-court suicide (p = 0.02), and the abdominal endurance test (p = 0.01). Mean improvements between pretrain and posttrain test sessions were 15% for the single-leg triple crossover hop, 10-11% for the baseline tests, 18% for the service line test, 21% for the 1-court suicide, 10% for the 2-court suicide, and 76% for the abdominal endurance test. No athlete sustained an injury or developed an overuse syndrome as a result of the training program. The results demonstrate that this program is feasible, low in cost, and appears to be effective in improving the majority of neuromuscular indices tested. We accomplished our goal of developing training and testing procedures that could all be performed on the tennis court.

The drop-jump video screening test: retention of improvement in neuromuscular control in female volleyball players.

A valgus lower limb alignment is commonly documented during noncontact anterior cruciate ligament injuries. We previously developed a videographic drop-jump test to measure overall lower limb alignment in the coronal plane as a screening tool to detect such an abnormal (valgus) position on landing. A neuromuscular retraining program developed for female athletes was shown to be effective in improving lower limb alignment on this test immediately after completion of training. What remained unknown was whether these improvements would be retained for longer periods of time. Therefore, this study was undertaken to determine if these improvements in overall lower limb alignment would be retained up to 1 year after the training. Sixteen competitive, experienced female high-school volleyball players underwent the video drop-jump test and then completed the neuromuscular retraining program. The program consisted of a dynamic warm-up, jump training, speed and agility drills, strength training, and static stretching and was performed 3 times a week for 6 weeks. The athletes repeated the drop-jump test immediately upon completion of training and then 3- and 12-months later. Significant improvements were found in the mean normalized knee separation distance between the pre and posttrained values for all test sessions (p < 0.01). Immediately after training, 11 athletes (69%) displayed significant improvements in the mean normalized knee separation distance that were retained 12 months later. Five athletes failed to improve. The video drop-jump test, although not a risk indicator for a knee ligament injury, provides a cost-effective general assessment of lower limb position and depicts athletes who have poor control on landing and acceleration into a vertical jump.

Reducing the risk of noncontact anterior cruciate ligament injuries in the female athlete.

High school and collegiate female athletes have a significantly increased risk of sustaining a noncontact anterior cruciate ligament injury compared with male athletes participating in the same sport. This review summarizes the current knowledge of the risk factors hypothesized to influence this problem, and the neuromuscular training programs designed to correct certain biomechanical problems noted in female athletes. The risk factors include a genetic predisposition for sustaining a knee ligament injury, environmental factors, anatomical indices, hormonal influences, and neuromuscular factors. The greatest amount of research in this area has studied differences between female and male athletes in movement patterns during athletic tasks; muscle strength, activation, and recruitment patterns; and knee joint stiffness under controlled, preplanned, and reactive conditions in the laboratory. Neuromuscular retraining programs have been developed in an attempt to reduce these differences. The successful programs teach athletes to control the upper body, trunk, and lower body position; lower the center of gravity by increasing hip and knee flexion during activities; and develop muscular strength and techniques to land with decreased ground reaction forces. In addition, athletes are taught to preposition the body and lower extremity prior to initial ground contact to obtain the position of greatest knee joint stability and stiffness. Two published programs have significantly reduced the incidence of noncontact anterior cruciate ligament injuries in female athletes participating in basketball, soccer, and volleyball. Other programs were ineffective, had a poor study design, or had an insufficient number of participants, which precluded a true reduction in the risk of this injury. In order to determine which risk factors for noncontact anterior cruciate ligament ruptures are significant, future investigations should include larger cohorts of athletes in multiple sports, analyze factors from all of the major risk categories, and follow athletes for at least one full athletic season. Future risk assessment studies should incorporate reactive tasks under more realistic sports conditions.

Posterolateral knee reconstruction with an anatomical bone-patellar tendon-bone reconstruction of the fibular collateral ligament.

BACKGROUND: The authors have long advocated a graft reconstruction of the fibular collateral ligament, believing that direct suture repair or augmentation procedures do not provide a stable construct. PURPOSE: To describe an operative technique and determine the clinical outcome of a bone-patellar tendon-bone graft anatomical replacement of the fibular collateral ligament in a consecutive series of knees. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A consecutive group of knees undergoing anatomical posterolateral reconstruction that included a fibular collateral ligament reconstruction with a bone-patellar tendon-bone graft was prospectively followed to determine the functional outcome and failure rate. Thirteen patients (14 posterolateral reconstructions) were observed 2 to 13.7 years postoperatively. All major posterolateral structures were surgically restored. The procedure represented a primary reconstruction in 7 patients and a revision in 6 patients. Anterior cruciate ligament ruptures were found in 7 patients and bicruciate ruptures in 5 patients, all of which were reconstructed. The rehabilitation protocol allowed immediate knee motion from 0 degrees to 90 degrees but included protection against lateral joint loads to prevent graft stretching and failure. The results were determined by a knee examination, stress radiography, KT-2000 arthrometer, the Cincinnati Knee Rating System, and the International Knee Documentation Committee Rating System. RESULTS: Significant improvements were found at follow-up for pain (P = .0001), swelling (P = .02), patient rating of the overall knee condition (P < .001), walking (P < .05), and stair climbing (P < .05). Thirteen of the 14 (93%) reconstructions restored normal or nearly normal lateral joint opening and external tibial rotation and 1 failed. The anterior cruciate ligament reconstructions were normal or nearly normal in 11 knees and abnormal in 1 knee. CONCLUSIONS: The anatomical posterolateral procedure was effective in restoring normal limits to lateral joint opening and external tibial rotation, allowed immediate knee motion, and appeared to protect other soft tissue repairs.

Effect of Fatigue Protocols on Lower Limb Neuromuscular Function and Implications for Anterior Cruciate Ligament Injury Prevention Training: A Systematic Review.

BACKGROUND: Approximately two-thirds of anterior cruciate ligament (ACL) tears are sustained during noncontact situations when an athlete is cutting, pivoting, decelerating, or landing from a jump. Some investigators have postulated that fatigue may result in deleterious alterations in lower limb biomechanics during these activities that could increase the risk of noncontact ACL injuries. However, prior studies have noted a wide variation in fatigue protocols, athletic tasks studied, and effects of fatigue on lower limb kinetics and kinematics. PURPOSE: First, to determine if fatigue uniformly alters lower limb biomechanics during athletic tasks that are associated with noncontact ACL injuries. Second, to determine if changes should be made in ACL injury prevention training programs to alter the deleterious effects of fatigue on lower limb kinetics and kinematics. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review of the literature using MEDLINE was performed. Key terms were fatigue, neuromuscular, exercise, hop test, and single-legged function tests. Inclusion criteria were original research studies involving healthy participants, use of a fatigue protocol, study of at least 1 lower limb task that involved landing from a hop or jump or cutting, and analysis of at least 1 biomechanical variable. RESULTS: Thirty-seven studies involving 806 athletes (485 female, 321 male; mean age, 22.7 years) met the inclusion criteria. General fatigue protocols were used in 20 investigations, peripheral protocols were used in 17 studies, and 21 different athletic tasks were studied (13 single-legged, 8 double-legged). There was no consistency among investigations regarding the effects of fatigue on hip, knee, or ankle joint angles and moments or surface electromyography muscle activation patterns. The fatigue protocols typically did not produce statistically significant changes in ground-reaction forces. CONCLUSION: Published fatigue protocols did not uniformly produce alterations in lower limb neuromuscular factors that heighten the risk of noncontact ACL injuries. Therefore, justification does not currently exist for major changes in ACL injury prevention training programs to account for potential fatigue effects. However, the effect of fatigue related to ACL injuries is worthy of further investigation, including the refinement of protocols and methods of analysis.

Anterior cruciate ligament revision reconstruction: results using a quadriceps tendon-patellar bone autograft.

BACKGROUND: The quadriceps tendon is a viable graft source for revision anterior cruciate ligament reconstruction. PURPOSE: To determine the functional results and graft failure rates in knees in which the patellar tendon had been previously harvested or was unavailable, expanded tunnels precluded the use of a semitendinosus-gracilis graft, or patients requested autogenous tissues instead of allografts for revision reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The authors observed 21 patients for a mean of 49 months postoperatively after revision anterior cruciate ligament reconstruction with a quadriceps tendon graft. The results were determined by KT-2000 arthrometer testing, the Cincinnati Knee Rating System, and the International Knee Documentation Committee Rating System. Fifteen knees required a concurrent procedure, including reconstruction of posterolateral structures in 5 knees, meniscal repairs in 5 knees, and high tibial osteotomy in 2 knees. RESULTS: Significant improvements occurred in symptoms (P < .0001), daily activities (P < .05), sports activities (P < .01), and the overall rating scores (P < .0001). Eighteen patients rated their knee condition as improved. Total mean anterior-posterior displacements decreased from 8.4 +/- 3.1 mm preoperatively to 2.0 +/- 2.3 mm at follow-up (P < .001). On the International Knee Documentation Committee knee ligament rating, 17 knees were graded as normal or nearly normal, 3 were graded as abnormal, and 1 was graded as severely abnormal. CONCLUSION: The revision operation provided reasonable results in this group of complex knees. However, the functional and overall results were inferior to those reported for primary anterior cruciate ligament reconstruction. Many knees (90%) had compounding problems of articular cartilage damage, meniscectomy, varus malalignment, or additional ligamentous injury that most likely affected the results.