Loss of extension following anterior cruciate ligament reconstruction: analysis of incidence and etiology using IKDC criteria

Manipulation Under Anesthesia and Lysis of Adhesions Are the Most Commonly Reported Treatments for Arthrofibrosis of the Knee After Arthroscopy or Anterior Cruciate Ligament Reconstruction in Both Pediatric and Adult Patients

Purpose

To systematically review the literature and provide a detailed summary of the current treatments and outcomes for arthrofibrosis following knee arthroscopy and anterior cruciate ligament reconstruction (ACLR) and to compare the treatment strategies in pediatric and adult populations.

Methods

A systematic review was performed in March 2022 using PubMed, EMBASE, and Cochrane Library Databases per Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Search terms consisted of variations of the following: ("arthrofibrosis" OR "stiffness" OR "stiff" OR "complications") AND ("arthroscopy" OR "arthroscop" OR "ACL" OR "anterior cruciate") AND ("treat" OR "care" OR "management" AND "knee"). The inclusion criteria were studies that were written in English, were published since 2000, and that reported outcomes of knee arthroscopy or ACLR for treatment of arthrofibrosis of the knee. The study quality was assessed, and data about the patients and treatments were recorded. Treatments were compared between pediatric and adult patients.

Results

A total of 1,208 articles were identified in the initial search, 42 (3.48%) of which met eligibility criteria, involving treatment regimens for arthrofibrosis following knee arthroscopy or ACLR. Of the 42 studies included, 29 (69.0%) were reported data for adults and 13 (31.0%) reported data for pediatric patients. Thirty-nine studies (92.8%) discussed manipulation under anesthesia and/or lysis of adhesions (LOA) as treatment for arthrofibrosis of the knee, whereas 2 (4.8%) described the use of medications.

Conclusions

Within orthopaedic sports medicine literature, there is variability in the reported treatment options for arthrofibrosis of the knee. Most studies identified manipulation under anesthesia and/or LOA as the treatment among both adult and pediatric patients. Other variants include notchplasty, open posterior arthrolysis, total graft resection, removal of hardware with LOA, dynamic splinting, casting in extension, bracing, and medications.

Level of Evidence

Level IV, systematic review of Level I-IV studies.

Risk Factors of Loss of Knee Range of Motion after Primary Anterior Cruciate Ligament Reconstruction following Preoperative Recovery of Knee Range of Motion

The loss of knee range of motion (ROM) is not an uncommon complication after anterior cruciate ligament reconstruction (ACLR). However, the risk factors of loss of knee ROM remain debatable. The purpose of this study was to evaluate the incidence and risk factors of loss of knee ROM at 12 months after primary ACLR performed after regaining full knee ROM preoperatively. Consecutive patients who underwent primary ACLR after regaining full ROM between January 2014 and January 2020 were retrospectively reviewed. Patients who received a surgical arthrolysis within 12 months after ACLR or those who had a loss of knee ROM at 12 months postoperatively were defined as the loss of ROM group. Possible risk factors of loss of knee ROM, including patient demographic, preoperative, surgical, and postoperative factors, were assessed. The notch wide index and radiographic parameters of the tibial spines; medial tibial spine height/tibial length (TL), lateral tibial spine height (LTSH)/TL, and tibial spine width (TSW)/TL, were also assessed. A total of 141 patients (141 knees) were included (mean age, 25.8 ± 11.4 years; male/female, 56/85). Of the 141 patients, three received surgical arthrolysis within 12 months, and 23 had a loss of knee ROM at 12 months after ACLR. On comparing patients with and without loss of knee ROM, significant differences were found in the age (p = 0.04), LTSH/TL (p = 0.02), and TSW/TL (p = 0.02). A multivariate regression analysis showed that the age (odds ratio [OR]; 1.05, 95% confidence interval [CI]: 1.01-1.09, p = 0.02), LTSH/TL (OR: 1.44, 95% CI: 1.01-2.1, p = 0.04), and TSW/TL (OR: 0.79, 95% CI: 0.65-0.97, p = 0.02) were identified as significant independent risk predictors of loss of knee ROM. This study showed that the incidence of loss of knee ROM at 12 months after primary ACLR was 18.4% (26/141). An older age, a higher LTSH/TL, and a smaller TSW/TL may be associated with loss of knee ROM at 12 months after ACLR.

Isokinetic Training Program to Improve the Physical Function and Muscular Performance of an Individual with Partial Injury of the Medial Meniscus: A Case Report

Background and Purpose

One of the best alternatives for the treatment of meniscal injuries in relation to surgical procedures, is exercise. This case report aimed to describe the effects of isokinetic training and a neuromuscular/proprioceptive exercise program on muscle performance and physical function in an individual after a rupture of the posterior horn of the medial meniscus.

Study Design

Case report.

Case Description

A 40-year-old man injured his right knee during a soccer match, with a partial lesion of the medial meniscus confirmed by magnetic resonance imaging. He completed an isokinetic training program in addition to exercises that targeted proprioception (22 sessions, 11 weeks) to improve physical function and performance, which were assessed before and after treatment and at a six-month follow-up. An individual with similar anthropometric characteristics was chosen to be used as a control for understanding the patient's assessment values.

Outcomes

Muscular performance of the knee flexors and extensors was evaluated isokinetically using the Biodex System-4 in a concentric mode at angular velocities of 60, 120, and 300 °/s . The main results indicated that after 11 weeks, the peak torque normalized to body mass (PT/BM), at 60 °/s of the knee extensors remained unchanged (2.54 N.m/kg) (below the control value - 3.06 N.m/kg), and at the six-month follow-up, increased by approximately 20% (3.08 N.m/kg). For the hamstrings, at 60 °/s, an increase of 18 % occurred after intervention (1.98 N.m/kg) and by approximately 30 % at the six-month follow-up (2.12 N.m/kg) - values much higher than the control 1.55 N.m/kg). This increase in the PT/BM was also reflected in the Hamstrings:Quadriceps ratio (78 %) after treatment which improved at follow-up (68 %).

Discussion

The results showed that the isokinetic training and neuromuscular/proprioceptive exercises improved the muscle performance of the knee flexors and extensors, after eleven weeks of intervention, and remained (or continued to improve) at the six-month follow-up.

Level of evidence

5, single case report.

Intervention of Refractory Arthrofibrosis After Anterior Cruciate Ligament Reconstruction: A Case Report

OBJECTIVES

Although nonsurgical and surgical management of knee arthrofibrosis has been reported in the literature, there is little information on the effect of procedural treatment modalities of refractory arthrofibrosis on clinical outcomes. The purpose of this case report is to describe the intervention of refractory knee arthrofibrosis after anterior cruciate ligament reconstruction and investigate long-term clinical outcomes after procedural intervention.

METHODS

A 27-year-old male presented with decreased range of motion (ROM), patellar mobility, strength, and knee joint function following anterior cruciate ligament reconstruction of his left knee. After failed conservative management, the patient underwent manipulation under anesthesia (MUA) to release scar tissue. Following MUA, the emphasis of comprehensive physiotherapy was on decreasing inflammation, relieving pain, and maintaining patellar mobility while increasing knee joint ROM and strength. Knee ROM, patellofemoral motion, gait, and quadriceps recruitment were measured 3, 6, 12, and 24 months after MUA.

RESULTS

At 2-year follow-up after MUA, the patient continued to present with decreased ROM and quadriceps strength compared to the contralateral knee, but had returned to a running program and reported knee joint dysfunction no longer interfered with his daily activities.

CONCLUSIONS

This case report demonstrates signs and symptoms that could indicate knee arthrofibrosis and introduces procedural intervention for refractory arthrofibrosis after anterior cruciate ligament reconstruction.

Preoperative Loss of Knee Extension Affects Knee Extension Deficit in Patients After Anterior Cruciate Ligament Reconstruction

Background

Loss of knee extension (LOE) after anterior cruciate ligament reconstruction (ACLR) is associated with limited knee joint function and increased risk for knee osteoarthritis.

Hypothesis

Preoperative LOE will affect postoperative LOE for up to 12 months after ACLR.

Study Design

Cohort study; Level of evidence, 2.

Methods

Included were patients who underwent anatomic ACLR between June 2014 and December 2018. In all patients, the postoperative rehabilitation protocol was the same. A heel height difference (HHD) ≥2 cm between the affected and the contralateral leg was used as a measure of LOE. Based on preoperative HHD, patients were divided into LOE and no-LOE groups. The HHD was reevaluated at 1, 3, 4, 6, 9, and 12 months postoperatively. Proportional hazards analysis was used, with the dependent variable being whether a postoperative HHD <2 cm was achieved; the independent variables being the presence or absence of preoperative LOE; and the adjusted variables being age, sex, time to surgery, and presence of meniscal sutures.

Results

A total of 389 patients (208 female, 181 male; median age, 21.0 years) were included in the study. There were 55 patients in the LOE group and 334 patients in the no-LOE group. The incidence of LOE at 12 months after ACLR was 13.8% in the no-LOE group and 38.2% in the LOE group (P < .001), with an absolute risk difference of 24.4%. The hazard ratio for achieving postoperative HHD <2 cm was 2.79 for the LOE group versus the no-LOE group (P < .001).

Conclusion

Patients with preoperative LOE were nearly 3 times more likely than those without LOE to have LOE at 12 months after ACLR.

Persistent knee extension deficits are common after anterior cruciate ligament reconstruction: a systematic review and meta-analysis of randomised controlled trials

PURPOSE

Knee extension deficits complicate recovery from ACL injury and reconstruction; however, the incidence of knee extension loss is not well defined. The aim of this review was to identify the incidence of loss of extension (LOE) following ACL rupture and reconstruction, explore the definitions of knee extension deficits reported and identify prognostic factors affecting LOE incidence.

METHODS

A systematic search was conducted in Medline, Cochrane Library and PEDro for studies in publication up to November 2021, with no restrictions on publication year. References were screened and assessed for inclusion using predetermined eligibility criteria. Randomised controlled trials (RCTs) that quantified knee angle, loss of extension or incidence of extension deficit were included for quality assessment and data extraction. Statistical summaries were generated and meta-analyses performed in two parts to examine: (i) the probability of a datapoint being zero incidence compared to a nonzero incidence and (ii) the relationship between the predictors and nonzero LOE incidence.

RESULTS

A sample of 15,494 studies were retrieved using the search criteria, with 53 studies meeting eligibility criteria. The pooled results from 4991 participants were included for analysis, with 4891 participants who had undergone ACLR. The proportion of included studies judged at an overall low risk of bias was small (7.8%). The observed group and study were the most important predictors for whether a datapoint reported an incidence of extension deficit. Time to follow-up (P < 0.001) and graft type (P = 0.02) were found to have a significant influence on nonzero LOE incidence (%). Covariate adjusted estimates of average LOE indicated 1 in 3 patients presenting with LOE at 12 month follow-up, reducing to 1 in 4 at 2 years.

CONCLUSIONS

This review examined the definitions for the measurement and interpretation of postoperative knee extension and established the trajectory of knee extension deficit after ACL injury and reconstruction. While factors associated with loss of extension were identified, the exact trajectory of knee extension deficits was difficult to infer due to discrepancies in measurement techniques and patient variation. On average, 1 in 3 patients may present with loss of extension of at least 3 degrees at 12-month follow-up, decreasing to 1 in 4 at 2 years. These results may be used by clinicians as an upper threshold for acceptable complication rates following ACLR. Future work should focus on LOE as a clinically relevant complication of ACL injury and treatment with appropriate attention to standardisation of definitions, measurements and better understanding of natural history.

PROSPERO REGISTRATION NUMBER

CRD42018092295.

LEVEL OF EVIDENCE

Level I.

Localized Anterior Arthrofibrosis After Soft-Tissue Quadriceps Tendon Anterior Cruciate Ligament Reconstruction Is More Common in Patients Who Are Female, Undergo Meniscal Repair, and Have Grafts of Larger Diameter

PURPOSE

To determine factors associated with localized anterior arthrofibrosis (cyclops lesion), such as graft size, warranting early reoperation for lysis of adhesions after anterior cruciate ligament reconstruction (ACLR) with all-soft tissue quadriceps tendon (ASTQT) autograft.

METHODS

All primary ASTQT autograft ACLRs within a single surgeon's prospectively collected registry with minimum 6-month follow-up were included. Patients who underwent multiligament knee reconstruction or cartilage restoration procedures were excluded. Localized anterior arthrofibrosis was defined as the requirement for a second procedure to achieve debridement and lysis of adhesions owing to the inability to regain terminal extension within 6 months of ACLR. The sex-specific incidence of arthrofibrosis was evaluated relative to age, weight, femoral and tibial tunnel sizes, meniscal repair, and meniscectomy by a binary logistic regression.

RESULTS

This study included 721 patients (46% female patients). There were 52 cases of localized anterior arthrofibrosis (7.2%). Female patients had a greater incidence of arthrofibrosis than male patients. Male patients with a femoral tunnel diameter of 9.25 mm or greater had an increased incidence of arthrofibrosis compared with those with a diameter of less than 9.25 mm, whereas a similar cutoff was not found to be statistically significant for female patients. Concomitant meniscal repair was associated with an increased risk of arthrofibrosis.

CONCLUSIONS

Female sex and concomitant meniscal repair were associated with an increased localized anterior arthrofibrosis incidence. Furthermore, ASTQT with a femoral tunnel diameter of 9.25 mm or greater in male patients was associated with an increased incidence of arthrofibrosis. LEVEL OF EVIDENCE: Level III, retrospective, comparative prognostic trial.

Complications following all-inside anterior cruciate ligament reconstruction

PURPOSE

We conducted a comprehensive analysis of possible perioperative complications following all-inside anterior cruciate ligament reconstruction (ACLR). Additional techniques and tips are proposed to prevent and manage complications.

METHODS

Complications following all-inside ACLR performed between December 2015 and December 2020 were retrospectively analysed. Altogether, 348 operations were performed and 275 patients were enrolled with a minimum 12-month follow-up period. Only semitendinosus autograft was utilised in most patients, and semitendinosus-gracilis autograft and allograft were used in five and 31 patients, respectively. Simultaneous meniscal repair, partial meniscectomy, and chondral surgery were performed in 29.5%, 21.1%, and 4.4% of patients, respectively. Complications were observed based on the patient's clinical condition, plain film, and magnetic resonance imaging. Clinical outcomes were assessed pre-operatively and at 12 months post-operatively, using the International Knee Documentation Committee form, Lysholm and Tegner activity scores, and KT1000 side-to-side difference.

RESULTS

Intraoperative and post-operative complications developed in 65 patients (23.6%). The most common complication was cortical button malposition on the femoral side (19.3%). Intra-operative breakage of the retrograde drill was found in two cases (0.73%), with three cases (1.1%) of over-drilling with destruction of the outer cortex. Post-operatively, four (1.5%), 13 (4.7%), and 16 (5.8%) cases of infection, full-thickness re-rupture, and loss of extension, respectively, were recorded. Functional outcome scales showed significant post-operative improvement.

CONCLUSION

Cortical button malposition was the most common but easily preventable complication. All-inside ACLR could be safe and promising after the suggested additional operative techniques and proper perioperative management which decrease complication rates and improve favourable outcomes.

Range of Motion, Strength, and Function After ACL Reconstruction Using a Contralateral Patellar Tendon Graft

BACKGROUND

Regaining preinjury levels of activity and progressing rehabilitation factors after anterior cruciate ligament (ACL) reconstruction have shown mixed results.

PURPOSE

To evaluate the timing and rate of return for knee range of motion (ROM), stability, strength, and subjective scores after ACL reconstruction with contralateral patellar tendon graft (PTG).

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Included were 2148 patients (1238 male patients, 910 female patients) who underwent primary ACL reconstruction with a contralateral PTG between 1995 and 2017 and had complete objective data through 3 months of follow-up. All patients participated in a rehabilitation program specific to goals for each knee. Patients were evaluated objectively with goniometric measurement of ROM, isokinetic quadriceps strength testing, and laxity with a KT-2000 arthrometer. Subjective data were collected at 2 and 5 years.

RESULTS

Normal extension on the reconstructed knee was attained for 95% of patients at 1 week postoperatively; normal flexion on the reconstructed knee was reached by 77% of patients by 3 months. At 3 months postoperatively, mean limb symmetry index strength was 104%, and the strength on the ACL-reconstructed and graft-donor knees was 87% and 86% of their respective preoperative strength. Mean manual maximum side-to-side difference in laxity was 2.0 mm at 1 month. Most patients (90%) returned to level 8 sports or higher and did so at an average of 5.7 months. Mean International Knee Documentation Committee scores for the ACL-reconstructed and graft-donor knees were 89 and 91 at 2 years (n = 1015 patients) and 84 and 90 at 5 years (n = 1275 patients), respectively. Mean Cincinnati Knee Rating Scale scores for the ACL-reconstructed and graft-donor knees were 92 and 96 at 2 years (n = 1184) and 88 and 94 at 5 years (n = 1236), respectively.

CONCLUSION

For patients who underwent ACL reconstruction with a contralateral PTG, postoperative ROM and strength were restored quickly by splitting the rehabilitation into different goals between the two knees. Using a contralateral PTG, this structured rehabilitation plan can lead to a relatively quick return to sport and good subjective long-term outcomes.

Early Identification of Arthrofibrosis in Adolescents Following Anterior Cruciate Ligament Reconstruction Is Associated With the Need for Subsequent Surgery: A Matched Case-Control Study

PURPOSE

To identify the postoperative characteristics associated with the need for subsequent surgical intervention in pediatric anterior cruciate ligament reconstruction (ACLR).

METHODS

Patients ≤18 years old who received operative treatment for arthrofibrosis following ACLR versus age- and sex-matched controls with a satisfactory postoperative course were retrospectively reviewed. The range of knee motion preoperatively and at each postoperative visit was recorded. Based on the typical post-operative protocols, visits were categorized into 3 groups: first (first 4 weeks), second (weeks 5-8), and third (weeks 9-16) visits. The deficit in the total arc of range of motion (ROM) in the operative knee relative to the nonoperative knee and the change in ROM between visits were compared. Receiver operating characteristic analysis was performed to determine the time point in which a diagnosis of arthrofibrosis could be predicted with the greatest accuracy.

RESULTS

In total, 18 patients with arthrofibrosis (mean age 14.2 ± 2.7 years, 9 male) and 36 control patients were included in the final analysis. Arthrofibrosis patients had significantly larger ROM deficits at all visits, 93° vs 69° for the first, 69° vs 24° for the second, and 56° vs 2º for the third, compared with controls (P < .001 for all). Pairwise comparisons showed that in arthrofibrosis cases, the total ROM did not change significantly between the second and third visits (P = .77), contrary to the controls. Receiver operating characteristic analysis revealed that the total ROM deficit of 50.7° at the second postoperative visit is 89% sensitive and 92.5% specific for development of arthrofibrosis.

CONCLUSIONS

We found that patients who go on to need manipulation of the knee under anesthesia/arthroscopic lysis of adhesions do not experience a significant improvement in ROM after the first 5-8 weeks, and that a ROM deficit of >50° at the 5- to 8-week mark postoperatively, is associated with ultimately needing operative intervention for arthrofibrosis. Based on these findings, it may be appropriate to intervene earlier if a patient still has a ROM deficit exceeding 50° by the second postoperative month.

LEVEL OF EVIDENCE

Level III, retrospective comparative prognostic trial.

Adolescent Athletes Demonstrate Inferior Objective Profiles at the Time of Return to Sport After ACLR Compared With Healthy Controls

Background:

Athletes display persistent muscle deficits and altered limb-loading mechanics at the time of return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR).

Purpose:

To compare an objective profile of adolescent athletes at RTS after ACLR to matched healthy controls.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

Included were 124 participants; 62 patients who underwent ACLR (15.4 ± 1.7 years) and 62 healthy controls (15.3 ± 1.7 years). Motion capture and force plates were used to capture joint motions during jump landing (JL) and single-limb squat (SLS) tasks. Energy absorption contribution (EAC) was calculated, and repeated-measures analysis of variance was used to assess for EAC differences between groups. Participants completed an International Knee Documentation Committee (IKDC) Subjective Knee Form, and isokinetic quadriceps and hamstring strength testing was performed on each limb. Independent t tests were run to examine age, height, weight, and IKDC scores as well as compare differences between groups for quadriceps and hamstring strength.

Results:

A significant group × joint interaction was found for JL (P < .001) and SLS (P < .001). For JL, patients who underwent ACLR utilized significantly greater hip (P < .001) and significantly less knee (P < .001) EAC on the surgical limb compared with controls. During SLS, patients who underwent ACLR utilized significantly greater hip (P < .001) and significantly less knee (P < .001) EAC on the surgical limb compared with controls. The ACLR cohort demonstrated lower IKDC scores (P < .001) and significantly lower quadriceps strength on the surgical limb (P < .001) than controls. There were no differences in surgical limb hamstring strength between the ACLR cohort and healthy controls (P = .701).

Conclusion:

Compared with matched healthy controls, the participants who underwent ACLR in this study demonstrated an inferior objective profile at RTS, consisting of deficits in surgical limb loading, self-reported outcomes, and strength.

In Vivo Knee Kinematics in Patients With Arthrofibrosis After Anterior Cruciate Ligament Reconstruction

Context: Arthrofibrosis after anterior cruciate ligament (ACL) reconstruction can be detrimental to the knee joint function and patient outcomes. However, the effects of arthrofibrosis on the in vivo tibiofemoral and patellofemoral joint kinematics after ACL reconstruction remain unclear. Objective: The objective of this study was to quantify the in vivo knee kinematics during a dynamic lunge task in the knee with arthrofibrosis after ACL reconstruction. Methods: Eleven patients with arthrofibrosis in one knee after ACL reconstruction participated in this study. Computed tomography and dual fluoroscopic imaging were used to evaluate in vivo kinematics of affected and contralateral knees during a lunge task. Differences in 6 degrees of freedom tibiofemoral kinematics and patellar tracking between limbs were assessed via repeated-measures analysis of variance. Results: Internal tibial rotation (5.2° vs 7.5°, respectively; P < .001) and inferior patellar shift (24.6 mm vs 28.9 mm, respectively; P < .001) were significantly lower in the arthrofibrotic knee compared with the contralateral knee from 15° to 75° of knee flexion. The patella in the arthrofibrotic knee significantly less flexed by 9.1° (P = .009) throughout the measured ROM and less laterally tilted by 3° (P = .017) compared with the contralateral knee from 30° to 75° of knee flexion. Conclusions: A significant superior shift and medial tilt of the patella were found in the affected knee compared with those in the contralateral knee during the dynamic lunge. Decreased internal tibial rotation and patellar flexion were found in knees with arthrofibrosis following ACL reconstruction; whether these kinematic changes are caused by arthrofibrosis need further investigation.

Post-traumatic osteoarthritis progression is diminished by early mechanical unloading and anti-inflammatory treatment in mice

OBJECTIVE

Post-traumatic osteoarthritis (PTOA) is a degenerative joint disease initiated by injury. Early phase (0-7 days) treatments often include rest (unloading) and anti-inflammatory medications, but how those early interventions impact PTOA progression is unknown. We hypothesized that early unloading and anti-inflammatory treatment would diminish joint inflammation and slow PTOA progression.

DESIGN

Mice were injured with non-invasive ACL rupture followed by hindlimb unloading (HLU) or normal cage activity (ground control: GC) for 7 days, after which all mice were allowed normal cage activity. HLU and GC mice were treated with daily celecoxib (CXB; 10 mg/kg IP) or vehicle. Protease activity was evaluated using in vivo fluorescence imaging, osteophyte formation and epiphyseal trabecular bone were quantified using micro-computed tomography, and synovitis and articular cartilage were evaluated using whole-joint histology at 7, 14, 21, and 28 days post-injury.

RESULTS

HLU significantly reduced protease activity (-22-30% compared to GC) and synovitis (-24-50% relative to GC) at day 7 post-injury (during unloading), but these differences were not maintained at later timepoints. Similarly, trabecular bone volume was partially preserved in HLU mice at during unloading (-14-15% BV/TV for HLU mice, -21-22% for GC mice relative to uninjured), but these differences were not maintained during reloading. Osteophyte volume was reduced by both HLU and CXB, but there was not an additive effect of these treatments (HLU: -46%, CXB: -30%, HLU + CXB: -35% relative to vehicle GC at day 28).

CONCLUSIONS

These data suggest that early unloading following joint injury can reduce inflammation and potentially slow PTOA progression.

Gender differences in knee kinematics during weight-bearing knee flexion for patients with arthrofibrosis after anterior cruciate ligament reconstruction

Background

Knowledge of tibiofemoral and patellofemoral joint kinematics is important for understanding gender-related dimorphism in developing knee arthrofibrosis and advancement of related treatments. The objective of our study was to investigate gender differences existing in tibiofemoral kinematics and patellar tracking in patients with arthrofibrosis after anterior cruciate ligament (ACL) reconstruction during weight-bearing knee flexion.

Methods

The tibiofemoral and patellofemoral joint kinematics were measured in 30 patients (15 male and 15 female) with arthrofibrosis after ACL reconstruction during a lunge task, using computed tomography and dual fluoroscopic imaging system. These data were analyzed for gender differences.

Results

The range of tibial rotation, patellar inferior shift, tilt, and flexion were significantly decreased in the affected knee compared to the contralateral knee from 15° to 75° of knee flexion (P ≤ 0.04). Statistically significant difference was detected for medial tibial translation between male and female patients at 60° (P = 0.04) and 75° of knee flexion (P = 0.02). The tibial rotation was significantly decreased at 60° (P = 0.03) and 75° of knee flexion (P < 0.01) in females. The inferior patellar shift in females was significantly lower than that in males at 15° (P = 0.04) and 30° of knee flexion (P = 0.01). The patellar tilt was significantly lower at 60° (P = 0.02) and 75° of knee flexion (P < 0.01) in females compared to males.

Conclusions

The results indicated a significant effect of gender on knee kinematics in patients with arthrofibrosis after ACL reconstruction during weight-bearing knee flexion. These gender differences in tibiofemoral kinematics and patellar tracking may warrant further investigations to determine implications for making gender-specific surgical treatments and rehabilitation programs.

Early cost estimating model for new bioabsorbable orthopedic implant candidates: A theoretical study

An early health technology assessment (HTA) study was performed to assess the need for developing a new bioabsorbable implant for the treatment of specific orthopedic injuries. The Anterior Cruciate Ligament Reconstruction (ACLR) procedure was selected based on the need and potential impact of bioabsorbable implants in the treatment of ACL injuries. The economic model considers the possible health events after an ACLR (failures and other complications such as stiffness and pain). A decision tree approach was used, and several sensitivity analyses were performed using a Monte Carlo simulation. A cost estimating model was applied comparatively for currently available metal and bioabsorbable implants against a potential new bioabsorbable implant with improved performance. A reduction in stiffness and pain symptoms were considered as targets for these new implants performance, with reduced inflammation resulting from the use of materials with appropriate biological and mechanical properties. The current study estimates that, under the assumptions made, the introduction of a new bioabsorbable implant in ACLR surgeries may generate yearly cost savings. The model estimates positive cost-benefits of the new implant when it reduces the probability of failure by more than 30%, or reduces at least 14% the probability of complications of an inflammatory nature. The development of a new bioabsorbable orthopedic implant for ACLR is encouraged by this study identifying the need for new bioabsorbable implants with improved biological and mechanical performance. The results of this early HTA have made it possible to anticipate design needs and objectives for the research and development of new orthopedic bioabsorbable implants.

Accuracy of Measuring Knee Flexion after TKA through Wearable IMU Sensors

Wearable sensors have the potential to facilitate remote monitoring for patients recovering from knee replacement surgery. Using IMU sensors attached to the patients' leg, knee flexion can be monitored while the patients are recovering in their home environment. Ideally, these flexion angle measurements will have an accuracy and repeatability at least on par with current clinical standards. To validate the clinical accuracy of a two-sensor IMU system, knee flexion angles were measured in eight subjects post-TKA and compared with other in-clinic angle measurement techniques. These sensors are aligned to the patients' anatomy by taking a pose resting their operated leg on a box; an initial goniometer measurement defines the patients' knee flexion while taking that pose. The repeatability and accuracy of the system was subsequently evaluated by comparing knee flexion angles against goniometer readings and markerless optical motion capture data. The alignment pose was repeatable with a mean absolute error of 1.6 degrees. The sensor accuracy through the range of motion had a mean absolute error of 2.6 degrees. In conclusion, the presented sensor system facilitates a repeatable and accurate measurement of the knee flexion, holding the potential for effective remote monitoring of patients recovering from knee replacement surgery.

Knee Extensor Mechanism Strength and Its Relationship to Patellofemoral Kinematics in Individuals With Arthrofibrosis Within 6 Months After Anterior Cruciate Ligament Reconstruction

CONTEXT

Performance in strength and assessment of patellar tracking is important for patients with arthrofibrosis after anterior cruciate ligament (ACL) reconstruction.

OBJECTIVE

The study was to examine the difference of patellofemoral kinematics between the affected and the contralateral limb and to evaluate the relationship between knee extensor strength and patellofemoral kinematics in patients with arthrofibrosis after ACL reconstruction.

DESIGN

Cohort study (diagnosis); level of evidence, 3.

SETTING

Laboratory.

PATIENTS

A prospective cohort of 20 patients with arthrofibrosis after ACL reconstruction was recruited.

INTERVENTIONS

A total of 20 patients who underwent arthroscopic reconstruction of the double-bundle ACL with a hamstring tendon autograft received standardized patellofemoral kinematics testing and knee extensor strength testing within 6 months after primary ACL reconstruction. Computed tomography and dual fluoroscopic imaging were used to evaluate in vivo patellofemoral kinematics of affected and contralateral knees during a lunge task. Knee extensor mechanism strength was measured using a handheld dynamometer.

MAIN OUTCOME MEASURES

A limb symmetry index of knee strength and patellar mobility was calculated and satisfactory performance defined as ≥90%.

RESULTS

There was a statistically significant decrease in the range of patellar inferior shift (P = .020; d = 0.81), flexion (P = .026; d = 0.95), lateral tilt (P = .001; d = 1.04), and lateral rotation (P < .001; d = 0.89) in the affected knee compared with the contralateral knee from 15° to 75° of knee flexion. There was a strong positive linear correlation between knee extensor strength and patellar inferior shift (r = .747; P = .008). A knee extensor strength limb symmetry index <90% was 89% sensitive and 9% specific for limited patellar inferior shift.

CONCLUSIONS

Patients with arthrofibrosis after ACL reconstruction presented decreased patellar mobility in the arthrofibrotic knee compared with the contralateral knee. The strong correlation between knee extensor strength and patellar inferior shift of the arthrofibrotic knee demonstrates the importance of knee extensor strength in the diagnosis and treatment of patients with knee arthrofibrosis. The knee extensor mechanism strength has high sensitivity but low specificity in identifying a decrease in patellar inferior shift in patients with arthrofibrosis after ACL reconstruction.

Knee Loading After ACL-R Is Related to Quadriceps Strength and Knee Extension Differences Across the Continuum of Care

Background:

Quadriceps strength and knee extension are believed to be important in the ability to effectively load the knee after anterior cruciate ligament (ACL) reconstruction (ACL-R).

Purpose:

To compare quadriceps strength (QUADS), side-to-side knee extension difference (ExtDiff), and knee energy absorption contribution (EAC) in patients preoperatively, 12 weeks postoperatively, and at return to sport (RTS). A secondary aim was to determine how the factors of QUADS and ExtDiff contributed to the ability to load the knee (knee EAC) at each of the 3 time points.

Study Design:

Case series; Level of evidence, 4.

Methods:

Overall, 41 individuals (mean ± SD age, 15.95 ± 1.63 years) were enrolled in this study. QUADS, ExtDiff, and knee EAC during a double-limb squat were collected preoperatively, 12 weeks postoperatively, and at RTS. Isokinetic QUADS was collected at 60 deg/s, normalized to body mass, and averaged across 5 trials. Knee extension was measured with a goniometer, and ExtDiff was calculated for analyses. Knee EAC was measured during double-limb squat descent and was calculated as a percentage of total energy absorption for the limb. Observations were obtained from both the surgical and nonsurgical limbs at the 3 time points. A mixed regression model with random intercept to compare change over the 3 time points was used, and a model selection was conducted with Akaike information criteria. Significance was set at P < .05.

Results:

Surgical limb QUADS was significantly lower preoperatively (mean ± SD, 1.37 ± 0.49 N·m/kg; P = .0023) and at 12 weeks (1.11 ± 0.38 N·m/kg; P < .0001) than at RTS (1.58 ± 0.47 N·m/kg). Nonsurgical limb QUADS was also significantly lower preoperatively (2.01 ± 0.54 N·m/kg; P < .0256) and at 12 weeks (2.03 ± 0.48 N·m/kg; P < .0233) than at RTS (2.18 ± 0.54 N·m/kg). Knee EAC for the surgical limb was significantly lower at 12 weeks than at RTS (40.98% ± 13.73% vs 47.50% ± 12.04%; P < .0032), and ExtDiff was significantly greater preoperatively than at RTS (–2.68° ± 3.19° vs –0.63° ± 1.43°; P < .0001). Preoperatively, QUADS for both the surgical (P < .0003) and nonsurgical (P = .0023) limbs was a significant predictor of surgical limb knee EAC, explaining 33.99% of the variance. At 12 weeks, surgical limb QUADS was a significant predictor (P < .0051) of surgical limb knee EAC, explaining 18.83% of the variance. At RTS, ExtDiff was a significant predictor (P = .0201) of surgical limb knee EAC, explaining 12.92% of the variance.

Conclusion:

The ability to load the knee after ACL injury changes across the continuum of care and is related to QUADS and ExtDiff. These results provide clinicians with insight into potential contributing factors that may limit knee loading during the rehabilitation process.

Subsequent Surgery for Loss of Motion After Anterior Cruciate Ligament Reconstruction Does Not Influence Function at 2 Years: A Matched Case-Control Analysis

BACKGROUND

Loss of motion (LOM) remains a common complication after anterior cruciate ligament (ACL) reconstruction and can be detrimental to patient outcomes after surgery. LOM is multifactorial, but nonsurgical and surgical solutions to this complex problem are available. A paucity of quality data exists evaluating clinical outcomes after the surgical treatment of patients with LOM after ACL reconstruction.

HYPOTHESIS

Patients undergoing surgical lysis of adhesions and manipulation under anesthesia for LOM after ACL reconstruction will exhibit decreased function, lower outcome scores, and delayed time of release to play when compared with matched controls without LOM.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A database of 1572 patients undergoing ACL reconstruction was sampled from 2013 to 2017 to identify a total of 58 patients (LOM group [n = 29] vs matched control group [n = 29]). Group comparisons were examined for patients requiring a second surgical procedure for LOM versus matched controls after ACL reconstruction for differences in surgical timing, self-reported International Knee Disability Committee scores, objective function at release to play, and subjective knee function at 2 years with the Single Assessment Numeric Evaluation. The risk of a type I error was set at α = .05 for all statistical analyses.

RESULTS

Patients who underwent lysis of adhesions and manipulation under anesthesia for LOM after ACL reconstruction exhibited no differences in Single Assessment Numeric Evaluation knee function at 2 years when compared with matched controls (85.8 ± 14.9 vs 88.0 ± 10.8, P = .606). All patients met release-to-play criteria. Only International Knee Disability Committee scores (P = .046) and single-legged hop testing (P = .050) reached statistically significant differences, with higher scores in the control group. There was no difference in the time to release to play (P = .034) or level of participation (P = .180) between the control and surgical groups. Subjective function scores at 2 years were not significantly different between groups. Tourniquet time during the index ACL reconstruction was shorter in the control group (P = .034).

CONCLUSION

The findings of this study suggest that patients who undergo surgical treatment for LOM after ACL reconstruction can release to play at similar times but display relative deficits in single-legged-hop symmetry and lower self-reported function when compared with matched controls. Longer surgical times may increase the risk for LOM after ACL reconstruction.

REGISTRATION

NCT03704376 (ClinicalTrials.gov identifier).

Recovery of knee extension and incidence of extension deficits following anterior cruciate ligament injury and treatment: a systematic review protocol

INTRODUCTION

Knee extension deficit or loss of extension (LOE) is a potential complication following ACL reconstruction (ACLR); however, the change in postoperative knee extension during rehabilitation is not well defined. The aim of this review is to establish the trajectory of knee extension recovery and incidence of knee extension deficit during rehabilitation after ACL rupture.

METHODS AND ANALYSIS

A systematic search will be conducted in MEDLINE, Embase, Cochrane Library, Scopus, SPORTDiscus, and relevant trials databases of English language papers in publication as of May 2018, with no restrictions on publication year applied. References will be screened and assessed for eligibility by two independent reviewers as per the PRISMA guidelines. Cohort, cross-sectional or case-controlled studies will be included for the analysis. Data extraction will be conducted using a predefined template and quality of evidence assessed. Statistical summaries and meta-analyses will be performed as necessary.

ETHICS AND DISSEMINATION

This review will provide clearer definitions for the measurement and interpretation of postoperative knee extension and establish its natural history after ACL reconstruction. Evidence of the incidence and factors associated with loss of extension will be identified. The findings of this systematic review will be disseminated in peer-reviewed journals and presented at national/international conferences.

TRIAL REGISTRATION

The protocol was registered on the PROSPERO international prospective register of systematic reviews prior to commencement (registration number CRD42018092295 ).

Association of the Graft Size and Arthrofibrosis in Young Patients After Primary Anterior Cruciate Ligament Reconstruction

INTRODUCTION

This study investigated the association of graft-related surgical factors and patient characteristics with the odds of arthrofibrosis after primary anterior cruciate ligament reconstruction (ACL-R).

METHODS

A retrospective case-control study assessed consecutive patients who underwent primary ACL-R in one tertiary pediatric hospital. Each arthrofibrosis case was matched to three controls for sex, calendar year, and age at the time of ACL-R, as well as the primary surgeon. Conditional multivariable logistic regression assessed the independent association of graft diameter, time from injury to ACL-R, concomitant knee pathologies, and body mass index.

RESULTS

Twenty arthrofibrosis cases of 1,121 ACL-R patients (incidence 1.8%) were matched to 60 controls resulting in the mean age of 14.5 years. An increase of 1 mm graft diameter was associated with 3.2-times increased odds of arthrofibrosis. Other variables were not independently associated with arthrofibrosis.

CONCLUSION

For young patients, the decision on the graft size must consider the possibility of arthrofibrosis with a larger graft versus reinjury with a smaller graft.

Complications and revision surgeries in two extra-articular tenodesis techniques associated to anterior cruciate ligament reconstruction. A case-control study

INTRODUCTION

Numerous techniques of anterior cruciate ligament (ACL) reconstruction associated to extra-articular tenodesis (EAT) have been described, but there have been few comparative studies, especially in terms of complications and revision procedures. The present study sought to compare two ACL reconstruction techniques using the patellar tendon (KJ): associating EAT by fascia lata (KJL2) or by gracilis (KJG). The study hypothesis was that the KJL2 technique incurs no extra risk of complications or surgical revision compared to the KJG technique.

METHOD

A prospective case-control study compared 41 patients undergoing KJL2 and 41 controls undergoing KJG. Complications, reconstruction failure and revision procedures were assessed at a mean 13 months follow-up (range, 6-20 months).

RESULTS

The KJL2 group showed no extra risk of postoperative complications or reconstruction failure compared to the KJG group: 1 versus 2 re-tears, respectively, not requiring revision. Revision surgery was significantly more frequent in the KJG group (31.7% vs. 7.3%), notably for arthrolysis and meniscectomy.

DISCUSSION

The KJL2 technique is reliable, without greater risk of complications or early revision surgery than the KJG technique.

LEVEL OF EVIDENCE

III - Case-control study.

Arthrofibrosis after ACL reconstruction is best treated in a step-wise approach with early recognition and intervention: a systematic review

PURPOSE

Arthrofibrosis is the most common post-operative complication of anterior cruciate ligament (ACL) reconstruction. Risk factors and management strategies for arthrofibrosis remain unclear. The purpose of this review was to: (a) describe existing definitions of arthrofibrosis, and (b) characterize the management strategies and outcomes of arthrofibrosis treatment.

METHODS

MEDLINE, EMBASE, and PubMed were searched from database inception to search date (March 21, 2016) and screened in duplicate for relevant studies. Data regarding patient demographics, indications, index surgery, management strategy, and outcomes were collected.

RESULTS

Twenty-five studies of primarily level IV evidence (88%) were included. A total of 647 patients (648 knees) with a mean age of 28.2 ± 1.8 years (range 14-62 years) were treated for arthrofibrosis following ACL reconstruction and followed for a mean 30.1 ± 16.9 months (range 2 months-9.6 years). Definitions of arthrofibrosis varied widely and included subjective definitions and the Shelbourne classification system. Patients were treated by one or more of: arthroscopic arthrolysis (570 patients), manipulation under anaesthesia (MUA) (153 patients), oral corticosteroids (31 patients), physiotherapy (81 patients), drop-casting (17 patients), epidural therapy combined with inpatient physiotherapy (six patients), and intra-articular interleukin-1 antagonist injection (four patients). All studies reported improvement in range of motion post-operatively, with statistically significant improvement reported for 306 patients (six studies, p range <0.001 to =0.05), and one study (18 patients) reporting significantly better results if arthrofibrosis was treated within 8 months of reconstruction (p < 0.03). The greatest improvements for extension loss were seen with drop-casting (mean 6.2° ± 0.6° improvement), whereas MUA produced the greatest improvement for flexion deficit (mean 47.8° ± 3.3° improvement).

CONCLUSIONS

Arthrofibrosis is poorly defined and outcome measures range varies widely. Amongst the studies included in this review, arthrofibrosis was most commonly managed surgically by arthroscopic arthrolysis, and most patients showed at least some improvement, including six studies that reported statistically significant change in ROM. In studies that used a step-wise approach to treating arthrofibrosis, more than half of patients were successfully treated without an operation. A more well-defined concept of arthrofibrosis, along with large, prospective studies will provide a clearer understanding of how to describe and manage this complication. The issue of arthrofibrosis following ACL reconstruction is clinically relevant as it represents a common complication of a commonly performed operation that nonetheless remains poorly defined and without clear treatment guidelines.

LEVEL OF EVIDENCE

Systematic Review of Level III and IV Studies, Level IV.

Effects of Notchplasty on Anterior Cruciate Ligament Reconstruction: A Systematic Review

Purpose  Notchplasty is a complementary surgical procedure often performed during anterior cruciate ligament reconstruction (ACLR) with the aim to widen the intercondylar notch and to avoid graft impingement. The aim of this review was to analyze the current literature evidence concerning the effects of notchplasty on clinical outcome after primary ACLR.

Methods  Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, and MEDLINE were used to search English language studies, from January 1990 to July 2015, concerning the effects of the notchplasty on ACLR, using the following keywords: “ACL” OR “anterior cruciate ligament” OR “ACL reconstruction” OR “anterior cruciate ligament reconstruction” AND “notch” OR “notchplasty” OR “intercondylar notch”. Randomized and nonrandomized trials, case series, technical notes, biomechanical studies and radiological study were included.

Results  At the final screening 16 studies were included. Despite widely used, the usefulness of notchplasty during ACLR remains unclear. Some concerns emerged regarding potential harmful effects of notchplasty, mostly related to the knee biomechanics and postoperative blood loss. Notchplasty can be useful in the treatment of arthrofibrosis and in presence of bony spurs of the notch both in primary and revision surgery. However, the level of evidence of available literature is poor and there is a strong need for randomized controlled trials investigating the role of notchplasty on ACLR.

Conclusion  We suggest being aware of potential complications following notchplasty during ACLR before deciding to perform notchplasty in primary ACLR, reserving it for the surgical management of arthrofibrosis, treatment of notch osteophytosis and revision ACLR.

Level of Evidence  Level IV, systematic review of level II-IV studies.

The Effect of Femoral Nerve Block on Quadriceps Strength in Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To assess the isokinetic, functional, and patient-reported outcomes of femoral nerve block (FNB) compared with traditional multimodal anesthesia for FNB in anterior cruciate ligament (ACL) reconstruction.

METHODS

A systematic search of PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature, Cochrane Reviews, and Google Scholar was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Effects of FNB on quadriceps function were evaluated by isokinetic testing, functional scoring systems, range of motion, and patient self-report questionnaires. Heterogeneous reporting of outcomes precluded a formal meta-analysis. The methodologic merit of all studies included was evaluated by the Coleman Methodology Score.

RESULTS

Six studies were identified with outcome measures reported between 7 days and 6 months postoperatively. At 6 months, 2 of 4 studies that reported isokinetic testing found significantly greater deficits among patients who received a nerve block; one of the remaining studies showed a deficit at 6 weeks but not 6 months. Limited data showed no significant differences in functional or patient-reported outcomes at 6 months after reconstruction, and data regarding the impact of FNB on return to sport were inconclusive. The mean Coleman Methodology Score for the included studies was 53, indicating poor overall methodologic quality of the available literature.

CONCLUSIONS

The limited data available suggest that FNB causes a measurable deficit in quadriceps isokinetic strength during the early postoperative period but has no effect on functional outcomes or return to sport at 6 months after ACL reconstruction. However, current clinical evidence is not sufficient to draw any valid or definitive conclusions regarding the effect of FNB on postoperative outcomes after ACL reconstruction.

LEVEL OF EVIDENCE

Level IV, systemic review of Level I through IV studies.

Hamstring Activity in the Anterior Cruciate Ligament Injured Patient: Injury Implications and Comparison With Quadriceps Activity

PURPOSE

To investigate the potential causes of diminished knee extension after acute anterior cruciate ligament (ACL) injury using both surface electromyography (sEMG) analysis of the quadriceps and hamstrings, and gait analysis to assess muscle action and tone.

METHODS

Consecutive patients with an acute ACL tear underwent sEMG and gait analysis within 2 weeks of injury, before ACL reconstruction. Standard motion analysis techniques were used and sEMG data were collected simultaneously with gait data. T-tests were used to determine differences between the ACL-deficient and control subjects in knee flexion angles, peak external knee joint moments, and total time that a muscle was activated ("on") during gait. External knee moments were expressed as a percentage of body weight times height.

RESULTS

Ten patients (mean age 24 ± 4 years) were included at a mean 10.2 days between injury and analysis; 10 uninjured, matched control subjects were included for comparison. There were significant increases in minimum flexion angle at heel strike (5.92 ± 3.39 v -3.49 ± 4.55, P < .001) and midstance (14.1 ± 6.23 v 1.20 ± 4.21, P < .001) in the injured limb compared with controls. There were significantly lower maximum external extension moments at heel strike (-0.99 ± 0.46 v -2.94 ± 0.60, P < .001) and during the second half of stance in the injured limb compared with controls (-0.56 ± 1.14 v -3.54 ± 1.31, P < .001). The rectus femoris was "on" significantly less during gait in the injured leg compared with controls (49.1 ± 7.76% v 61.0 ± 14.8%, P = .044). There were no significant differences in hamstring activity "on" time during gait (P > .05).

CONCLUSIONS

In patients with acute ACL injury, the ACL-deficient limb does not reach as much extension as controls. Although the rectus femoris is "on" for shorter periods during the gait cycle, there is no difference in hamstring time on during gait. This information may help clinicians better understand muscle function and gait patterns in the acute time period after ACL injury.

LEVEL OF EVIDENCE

Level III, case control study.

Editorial Commentary: Postoperative Anterior Cruciate Ligament Reconstruction Protocols Are Like Snowflakes; No 2 Are Alike

Postoperative rehabilitation after arthroscopic and related surgery should follow guidelines that emphasize time (tissue healing) and performance (motion and strength) milestones. These guidelines are often missing in traditional protocols, which assume that all patients arrive in the same condition at the same point in time. The real challenge for the allied health professional will be demonstrating that milestone-based protocols that use the best available evidence are effective, and as a start, we need to eliminate treatments proven ineffective.

The Importance of Patient Sex in the Outcomes of Anterior Cruciate Ligament Reconstructions: A Systematic Review and Meta-analysis

BACKGROUND

One of the well-studied epidemiological phenomena of anterior cruciate ligament (ACL) injuries is the 2- to 9-fold increase in the relative risk of ACL rupture in female athletes compared with male athletes. However, the influence of patient sex on the outcome after ACL reconstruction remains unclear, with some authors reporting inferior outcomes in females and others noting no significant difference.

PURPOSE

To provide a comprehensive systematic review and meta-analysis to examine the possible association between patient sex and the subjective and objective outcomes after ACL reconstruction.

METHODS

This study was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. All studies that reported clinical outcomes after ACL reconstruction in males and females independently were included in the review. A quantitative random-effects meta-analysis was performed to compare outcomes between sexes. For outcomes with considerable heterogeneity, meta-regression was used to identify potential moderators. Articles were evaluated qualitatively when quantitative data were not reported.

RESULTS

A total of 135 publications were included in the review. Females had inferior outcomes in instrumented laxity (standardized mean difference [SMD], 0.24; 95% CI, 0.11-0.37), revision rate (relative risk [RR], 1.15; 95% CI, 1.02-1.28), Lysholm score (SMD, -0.33; 95% CI, -0.55 to -0.11), Tegner activity scale (SMD, -0.37; 95% CI, -0.49 to -0.24), and incidence of not returning to sports (RR, 1.12; 95% CI, 1.04-1.21), all of which were statistically significant. Other outcomes were comparable between sexes, including anterior drawer test, Lachman test, pivot-shift test, timed single-legged hop test, single-legged hop test, quadriceps testing, hamstring testing, extension loss, flexion loss, development of cyclops lesion, and International Knee Documentation Committee (IKDC) knee examination score. Females and males were equally likely to develop anterior knee pain and osteoarthritis after ACL reconstruction. The graft rupture and graft failure rates did not differ significantly between sexes.

CONCLUSION

There were comparable or inferior results for females compared with males in all outcomes analyzed. No statistically significant sex difference was identified in most of the objective parameters. However, subjective and functional outcomes, including Lysholm score, Tegner activity scale, and ability to return to sports, have been shown to be poorer in females.

Patient Outcomes and Predictors of Success After Revision Anterior Cruciate Ligament Reconstruction

Background:

Patient outcomes and predictors of success after revision anterior cruciate ligament (ACL) reconstruction are currently limited in the literature. Existing studies either have a small study size or are difficult to interpret because of the multiple surgeons involved in the care of the study sample.

Purpose:

To determine patient outcomes and predictors of success or failure after a single-stage revision ACL reconstruction by a single fellowship-trained senior surgeon at a single institution.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 78 patients who underwent revision ACL reconstruction by a single surgeon from 2010 to 2014 were contacted and available for follow-up. The mean time from revision procedure to follow-up was 52 months. Those patients who were able to participate in the study sent in a completed Tegner activity level scale, International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, and IKDC Current Health Assessment Form. The patients’ medical records were also thoroughly reviewed.

Results:

Five patients had subsequent failure after revision surgery. The median Tegner score was 6 at follow-up, and the mean subjective IKDC score was 72.5. There was no statistically significant difference in outcome scores when comparing revision graft type, body mass index, sex, need for bone grafting, and time from failure to revision. Patients with failures after primary ACL reconstruction secondary to a traumatic event were found to have statistically significantly higher IKDC scores (mean, 76.6) after revision when compared with nontraumatic failures (mean, 67.1), even when controlling for confounders (P < .017).

Conclusion:

Revision ACL reconstruction is effective in improving patient activity levels and satisfaction. However, the subjective IKDC results are quite variable and likely based on multiple factors. Patients with traumatic injuries contributing to graft failure after primary ACL reconstruction had a statistically significantly, although not clinically significant, higher IKDC score after revision surgery compared with nontraumatic failures. These data may be useful when counseling a patient on whether to pursue revision ACL reconstruction surgery.

Knee Extension Range of Motion at 4 Weeks Is Related to Knee Extension Loss at 12 Weeks After Anterior Cruciate Ligament Reconstruction

Background:

The anterior cruciate ligament (ACL) is commonly torn, and surgical reconstruction is often required to allow a patient to return to their prior level of activity. Avoiding range of motion (ROM) loss is a common goal, but little research has been done to identify when ROM loss becomes detrimental to a patient’s future function.

Purpose:

To determine whether there is a relationship between early knee side-to-side extension difference after ACL reconstruction and knee side-to-side extension difference at 12 weeks. The hypothesis was that early (within the first 8 weeks) knee side-to-side extension difference will be predictive of knee side-to-side extension difference seen at 12 weeks.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Knee side-to-side extension difference measures were taken on 74 patients undergoing ACL reconstruction rehabilitation at the initial visit and 4, 8, and 12 weeks postoperatively. Visual analog scores (VAS) and International Knee Documentation Committee (IKDC) scores were also recorded at these time frames.

Results:

There was a strong relationship between knee extension ROM at 4 and 12 weeks (r = 0.639, P < .001) and 8 and 12 weeks (r = 0.742, P < .001). When the variables of knee extension ROM at initial visit and 4 and 8 weeks were entered into a regression analysis, the predictor variable explained 61% (R² = 0.611) of variance for knee extension ROM at 12 weeks, with 4 weeks (R² = 0.259) explaining the majority of this variance.

Conclusion:

This study found that a patient’s knee extension at 4 weeks was strongly correlated with knee extension at 12 weeks.

Clinical Relevance:

This information may be useful for clinicians treating athletic patients who are anxious for return to sport by providing them an initial goal to work toward in hopes of ensuring successful rehabilitation of their knee.

A Systematic Review of Failed Anterior Cruciate Ligament Reconstruction With Autograft Compared With Allograft in Young Patients

CONTEXT

The advantages of allograft anterior cruciate ligament reconstruction (ACLR), which include shorter surgical time, less postoperative pain, and no donor site morbidity, may be offset by a higher risk of failure. Previous systematic reviews have inconsistently shown a difference in failure prevalence by graft type; however, such reviews have never been stratified for younger or more active patients.

OBJECTIVE

To determine whether there is a different ACLR failure prevalence of autograft compared with allograft in young, active patients.

DATA SOURCES

EMBASE, MEDLINE, Cochrane trials registry.

STUDY SELECTION

Comparative studies of allograft versus autograft primary ACL reconstruction in patients <25 years of age or of high-activity level (military, Marx activity score >12 points, collegiate or semiprofessional athletes).

STUDY DESIGN

Systematic review with meta-analysis.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

Manual extraction of available data from eligible studies. Quantitative synthesis of failure prevalence and Lysholm score (outcomes in ≥3 studies) and I (2) test for heterogeneity. Assessment of study quality using CLEAR NPT and Newcastle-Ottawa Scale (NOS).

RESULTS

Seven studies met inclusion criteria (1 level 1; 2 level 2, 4 level 3), including 788 patients treated with autograft tissue and 228 with various allografts. The mean age across studies was 21.7 years (64% male), and follow-up ranged between 24 and 51 months. The pooled failure prevalence was 9.6% (76/788) for autografts and 25.0% (57/228) for allografts (relative risk, 0.36; 95% CI, 0.24-0.53; P < 0.00001; I (2) = 16%). The number needed to benefit to prevent 1 failure by using autograft was 7 patients (95% CI, 5-10). No difference between hamstrings autograft and patella tendon autograft was noted. Lysholm score was reported in 3 studies and did not differ between autograft and allograft.

CONCLUSION

While systematic reviews comparing allograft and autograft ACLR have been equivocal, this is the first review to examine young and active patients in whom allograft performs poorly.

Controversies in knee rehabilitation: anterior cruciate ligament injury

Controversy in management of athletes exists after anterior cruciate ligament (ACL) injury and reconstruction. Consensus criteria for evaluating successful outcomes following ACL injury include no reinjury or recurrent giving way, no joint effusion, quadriceps strength symmetry, restored activity level and function, and returning to preinjury sports. Using these criteria, the success rates of current management strategies after ACL injury are reviewed and recommendations are provided for the counseling of athletes after ACL injury.

The in vivo relationship between anterior neutral tibial position and loss of knee extension after transtibial ACL reconstruction

BACKGROUND

Restoration of anterior tibial stability while avoiding knee extension deficit are a common goal of anterior cruciate ligament (ACL) reconstruction. However, achieving this goal can be challenging. The purpose of this study was to determine whether side-to-side differences in anterior tibial neutral position and laxity are correlated with knee extension deficit in subjects 2 years after ACL reconstruction.

METHODS

In the reconstructed and contralateral knees of 29 subjects with transtibial reconstruction, anterior tibiofemoral neutral position was measured with MRI and three-dimensional modeling techniques; terminal knee extension at heel strike of walking and during a seated knee extension were measured via gait analysis; and anterior laxity was measured using the KT-1000.

RESULTS

Knees that approached normal anterior stability and anterior tibial position had increased extension deficit relative to the contralateral knee. On average the reconstructed knee had significantly less (2.1±4.4°) extension during active extension and during heel strike of walking (3.0±4.3º), with increased anterior neutral tibial position (2.5±1.7 mm) and anterior laxity (1.8±1.0 mm). There was a significant correlation between side-to-side difference in anterior neutral tibial position with both measures of knee extension (walking, r=-0.711, p<0.001); active knee extension, r=-0.544, p=0.002).

CONCLUSION

The results indicate a relationship between the loss of active knee extension and a change in anterior neutral tibial position following non-anatomic transtibial ACL reconstruction. Given the increasing evidence of a link between altered kinematics and premature osteoarthritis, these findings provide important information to improve our understanding of in vivo knee function after ACL reconstruction.

Preoperative patient and injury factors of successful rehabilitation after anterior cruciate ligament reconstruction with single-bundle techniques

PURPOSE

The aim of this systematic review was to determine which patient determinants and injury factors, before anterior cruciate ligament reconstruction by arthroscopic single-bundle techniques, affect postoperative rehabilitation.

METHODS

A search of PubMed, Embase, and the Cochrane Database of Clinical Trials was performed up to February 2013. After application of our inclusion criteria, a final selection was made based on studies' methodologic score assessed with the Newcastle-Ottawa Scale. Meta-analysis was planned for each prognostic factor when data were considered clinically and statistically homogeneous.

RESULTS

Meta-analysis showed that male patients have better functional outcomes. Qualitative synthesis from 18 high-quality studies showed that patients operated on before 30 years of age reach higher activity levels. Patients with high baseline body mass index have lower activity levels after surgery. Smoking results in more symptoms and lower activity levels and subjective scores. Reconstruction before 3 months results in higher activity levels. Preoperatively, a less than 20% quadriceps strength difference, 50° of tibial external rotation or less, absence of flexion deficits, low knee influence on the patient's activity level, and less anterior knee pain result in higher functional scores. Preoperative anterior laxity difference does not predict functional scores. The prognostic value of preoperative activity and competition level for postoperative functional outcome is controversial. Patients with concomitant meniscal injuries have worse functional outcomes. The prognostic value of concomitant chondral pathology for postoperative functional outcome is controversial. Collateral ligament injury could predict functional scores or activity level.

CONCLUSIONS

Male gender, patient age younger than 30 years, reconstruction before 3 months, and high baseline activity level contribute to better functional outcomes. Smoking, high body mass index, quadriceps strength, and range-of-motion deficits affect rehabilitation negatively. Preoperative anterior laxity does not influence rehabilitation. The role of preoperative prognostic injury factors remains unclear because of limited evidence.

LEVEL OF EVIDENCE

Level III, systematic review of Level II and III studies.

The relationship between peak knee extension at heel-strike of walking and the location of thickest femoral cartilage in ACL reconstructed and healthy contralateral knees

Reports that knee cartilage health is sensitive to kinematic changes, combined with reports of extension loss following ACL reconstruction, underscores the importance of restoring ambulatory knee extension in the context of preventing premature osteoarthritis. The purpose of this study was to test the relationship between individual variations in peak knee extension at heel-strike of walking and the anterior-posterior location of thickest cartilage in the medial and lateral femoral condyles of healthy contralateral and ACL reconstructed knees. In vivo gait analysis and knee MR images were collected from 29 subjects approximately 2 years after unilateral ACL reconstruction. Knee extension was measured at heel-strike of walking and 3-D femoral cartilage thickness models were reconstructed from MR images. The ACL reconstructed knees had significantly reduced knee extension (-1.5±4.2°) relative to the contralateral knees (-4.6±3.4°) at heel-strike of walking but did not have side-to-side differences in the anterior-posterior location or magnitude of thickest medial and lateral femoral cartilage. The anterior-posterior location of the thickest medial femoral cartilage was correlated with knee extension at heel-strike in both the healthy contralateral (R(2)=0.356, p<0.001) and reconstructed (R(2)=0.234, p=0.008) knees. These results suggest that ACL reconstruction can impair terminal extension at periods of ambulatory loading known to be related to cartilage morphology in healthy joints. The fact that the femoral cartilage thickness distribution had not changed at 2 years post-op, even in the subset of subjects with extension loss, suggests that loads may be shifted to thinner cartilage regions, which could have important implications on long-term joint health.

Revision anterior cruciate ligament reconstruction: an update

With the rising number of anterior cruciate ligament (ACL) reconstructions performed, revision ACL reconstruction is increasingly common nowadays. A broad variety of primary and revision ACL reconstruction techniques have been described in the literature. Recurrent instability after primary ACL surgery is often due to non-anatomical ACL graft reconstruction and altered biomechanics. Anatomical reconstruction must be the primary goal of this challenging revision procedure. Recently, revision ACL reconstruction has been described using double bundle hamstring graft. Successful revision ACL reconstruction requires an exact understanding of the causes of failure and technical or diagnostic errors. The purpose of this article is to review the causes of failure, preoperative evaluation, graft selection and types of fixation, tunnel placement, various types of surgical techniques and clinical outcome of revision ACL reconstruction.

Guideline on anterior cruciate ligament injury

The Dutch Orthopaedic Association has a long tradition of development of practical clinical guidelines. Here we present the recommendations from the multidisciplinary clinical guideline working group for anterior cruciate ligament injury. The following 8 clinical questions were formulated by a steering group of the Dutch Orthopaedic Association. What is the role of physical examination and additional diagnostic tools? Which patient-related outcome measures should be used? What are the relevant parameters that influence the indication for an ACL reconstruction? Which findings or complaints are predictive of a bad result of an ACL injury treatment? What is the optimal timing for surgery for an ACL injury? What is the outcome of different conservative treatment modalities? Which kind of graft gives the best result in an ACL reconstruction? What is the optimal postoperative treatment concerning rehabilitation, resumption of sports, and physiotherapy? These 8 questions were answered and recommendations were made, using the "Appraisal of Guidelines for Research and Evaluation" instrument. This instrument seeks to improve the quality and effectiveness of clinical practical guidelines by establishing a shared framework to develop, report, and assess. The steering group has also developed 7 internal indicators to aid in measuring and enhancing the quality of the treatment of patients with an ACL injury, for use in a hospital or practice.

Allograft anterior cruciate ligament reconstruction: indications, techniques, and outcomes

The anterior cruciate ligament (ACL) is an important stabilizer of the knee against translational and rotational forces. The goal of anatomic reconstruction of the ACL-deficient knee is to re-create a stable knee that will allow for return to sport and prevent recurrent injury. Multiple graft options exist for ACL reconstruction, and each option has unique advantages and disadvantages. With appropriate patient selection, each graft can be utilized to optimize patient outcomes. Allograft options limit morbidity following ACL reconstruction, but care must be taken with surgical technique and postoperative rehabilitation to allow for graft incorporation. An understanding of the surgical technique and differences between graft options will allow the patient, surgeon, and physical therapist to maximize outcomes following ACL reconstruction.

Current concepts for anterior cruciate ligament reconstruction: a criterion-based rehabilitation progression

The management of patients after anterior cruciate ligament reconstruction should be evidence based. Since our original published guidelines in 1996, successful outcomes have been consistently achieved with the rehabilitation principles of early weight bearing, using a combination of weight-bearing and non-weight-bearing exercise focused on quadriceps and lower extremity strength, and meeting specific objective requirements for return to activity. As rehabilitative evidence and surgical technology and procedures have progressed, the original guidelines should be revisited to ensure that the most up-to-date evidence is guiding rehabilitative care. Emerging evidence on rehabilitative interventions and advancements in concomitant surgeries, including those addressing chondral and meniscal injuries, continues to grow and greatly affect the rehabilitative care of patients with anterior cruciate ligament reconstruction. The aim of this article is to update previously published rehabilitation guidelines, using the most recent research to reflect the most current evidence for management of patients after anterior cruciate ligament reconstruction. The focus will be on current concepts in rehabilitation interventions and modifications needed for concomitant surgery and pathology.

LEVEL OF EVIDENCE

Therapy, level 5.

Anterior cruciate ligament allograft surgery: underreporting of graft source, graft processing, and donor age

BACKGROUND

There has been much controversy regarding the effects of sterilization techniques and graft history on the structural integrity of allograft ligaments used in reconstruction of the anterior cruciate ligament. The purpose of this review was to comprehensively examine anterior cruciate ligament allograft studies published in the last decade to evaluate the extent to which tissue source, tissue processing techniques, and donor age are reported.

METHODS

The authors reviewed 202 articles published from 1999 through November 2009, of which 68 retrospective, prospective, biomechanical, and histology studies evaluating 4689 allografts were included.

RESULTS

The majority of studies do not accurately report key elements of graft history including tissue bank, processing or sterilization technique, or donor age. Underreporting was particularly prominent in clinical studies as compared with basic science studies. Limited reporting of allograft processing, allograft source, and donor age raises serious questions regarding the generalizability of published studies of allograft tissue for anterior cruciate ligament reconstruction. Conclusion/

CLINICAL RELEVANCE

Orthopaedic surgeons who use allograft tissue must understand the tissue treatments being used (ie, preservation methods, chemical and sterilization processes) to best inform their patients regarding the risks, benefits, and long-term outcomes when such tissues are used. A complete understanding of the implanted tissue, as well as surgeon and recipient demographics, is necessary to ensure appropriate and predictable long-term outcomes.

High-intensity mechanical therapy for loss of knee extension for worker's compensation and non-compensation patients

Background

Knee flexion contractures have been associated with increased pain and a reduced ability to perform activities of daily living. Contractures can be treated either surgically or conservatively, but these treatment options may not be as successful with worker's compensation patients. The purposes of retrospective review were to 1) determine the efficacy of using adjunctive high-intensity stretch (HIS) mechanical therapy to treat flexion contractures, and 2) compare the results between groups of worker's compensation and non-compensation patients.

Methods

Fifty-six patients (19 women, 37 men, age = 51.5 ± 17.0 years) with flexion contractures were treated with HIS mechanical therapy as an adjunct to outpatient physical therapy. Mechanical therapy was only prescribed for those patients whose motion had reached a plateau when treated with physical therapy alone. Patients were asked to perform six, 10-minute bouts of end-range stretching per day with the ERMI Knee Extensionater^(r) (ERMI, Inc., Atlanta, GA). Passive knee extension was recorded during the postoperative visit that mechanical therapy was prescribed, 3 months after beginning mechanical therapy, and at the most recent follow-up. We used a mixed-model 2 × 3 ANOVA (group × time) to evaluate the change in passive knee extension between groups over time.

Results

Regardless of group, the use of adjunctive HIS mechanical therapy resulted in passive knee extension deficits that significantly improved from 10.5° ± 5.2° at the initial visit to 2.6° ± 3.5° at the 3 month visit (p < 0.001). The degree of extension was maintained at the most recent follow-up (2.0° ± 2.9°), which was significantly greater than the initial visit (p < 0.001), but did not differ from the 3 month visit (p = 0.23). The gains in knee extension did not differ between worker's compensation and non-compensation patients (p = 0.56).

Conclusions

We conclude that the adjunctive use of HIS mechanical therapy is an effective treatment option for patients with knee flexion contractures, regardless of whether the patient is being treated as part of a worker's compensation claim or not.

Preoperative factors correlating with prolonged range of motion deficit after anterior cruciate ligament reconstruction

BACKGROUND

Impaired postoperative range of motion remains one of the most frequent complications after anterior cruciate ligament reconstruction.

PURPOSE

This study was undertaken to determine the preoperative factors associated with prolonged range of motion deficit after anterior cruciate ligament reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Between January 2007 and March 2008, a consecutive series of 217 patients underwent anterior cruciate ligament reconstruction and were reviewed at 6 weeks and 3 months after surgery. In this series, all data of patients who required a further surgery for arthrolysis until December 2009 were studied. Goniometric range of motion measurement was performed the day before surgery and at 6 weeks and 3 months postoperatively. Bone contusions were analyzed on preoperative magnetic resonance imaging (MRI). All MRI scans were performed in the 6 months before surgery. Seven potential risk factors-age, sex, limited preoperative range of motion, meniscal lesions, bone contusion(s), operative delay less than 45 days, and rehabilitation-were assessed using univariate analysis. The correlations between the significant factors previously identified were analyzed further using multivariate logistic regression analysis.

RESULTS

Limited preoperative range of motion (P < .001), typical bone contusions of the lateral compartment (P < .001), operative delay less than 45 days (P = .003), and female sex (P = .049) were found to be significantly correlated with delayed recovery. The limited preoperative mobility and the presence of typical contusions were strongly correlated (P < .001). In the group of patients who underwent surgery within 45 days, delayed recovery was strongly correlated with limited preoperative mobility (P = .0008) and to the presence of typical contusions (P < .001). Arthrolysis was correlated with delayed range of motion (odds ratio [OR], 8.2; 95% confidence interval [CI], 1.9-50; P =.001) and bone bruise (OR, 7.6; 95% CI, 1.7-46.1; P = .002).

CONCLUSION

Preoperative limited range of motion and typical bone bruises of the lateral femoral condyle and tibial plateau are major risk factors for a difficult rehabilitation after anterior cruciate ligament reconstruction.

Knee pain and mobility impairments: meniscal and articular cartilage lesions

The Orthopaedic Section of the American Physical Therapy Association presents this fifth set of clinical practice guidelines on knee pain and mobility impairments, linked to the International Classification of Functioning, Disability, and Health (ICF). The purpose of these practice guidelines is to describe evidence-based orthopaedic physical therapy clinical practice and provide recommendations for (1) examination and diagnostic classification based on body functions and body structures, activity limitations, and participation restrictions, (2) interventions provided by physical therapists, (3) and assessment of outcome for common musculoskeletal disorders.

Factors affecting patients' graft choice in anterior cruciate ligament reconstruction

Background

Multiple studies have reported that allografts are acceptable alternatives to autografts for anterior cruciate ligament (ACL) reconstructions. Our clinical practice allows patient involvement in graft decision-making. This study examined the patients' preference for graft selection and the factors affecting their decision.

Methods

Patients scheduled to undergo an ACL reconstruction surgery (n = 129) at a university medical center in Korea were enrolled in this study. Information leaflets with graft descriptions were provided prior to hospital admission, and the patients were allowed to choose one of two surgical graft types. The patients were asked to complete a questionnaire that reflected their decision-making processes, and the patients' trends and factors affecting their choice of graft were analyzed based on their responses.

Results

Most patients (54.3%) selected autografts for the ACL reconstruction. The surgeon's explanation was the most important factor affecting the final patient decision followed by the information derived from Internet searches. Patients who derived the majority of their understanding of the graft types from the Internet chose allografts at significantly higher rates.

Conclusions

Patient graft selection is a reasonable way of designating the type of surgical procedure. Most patients selected autografts for their ACL reconstruction. However, patients who performed significant Internet-based research tended to prefer allografts.