ACL reconstruction using bone-patellar tendon-bone press-fit fixation: 10-year clinical results

Ten-year outcomes of anterior cruciate ligament reconstruction with hamstring tendon autograft and femoral fixation with a cortico-cancellous screw suspension device

PURPOSE

To evaluate the clinical and radiographic outcomes of anterior cruciate (ACL) reconstruction at minimum 10-year follow-up.

METHODS

Ninety-three patients who underwent primary unilateral ACL reconstruction with hamstring tendon autograft, transtibial technique and femoral cortico-cancellous screw suspension device (Athrax, Leader Medica s.r.l) between 2010 and 2012 were retrospectively reviewed. Mean follow-up was 136 months. Evaluation was performed using the International Knee Documentation Committee score (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Score and Tegner Activity Level Scale. Incidence of OA was determined by comparing standard anteroposterior and lateral weightbearing radiographs of the ACL-reconstructed and contralateral knee. Osteoarthritis severity was graded according to the Kellgren-Lawrence (KL) score.

RESULTS

Median Tegner activity level was 6 (5-7). Lysholm and IKDC scores were 100 (95-100) and 90 (86-95), respectively, KOOS was 98 (95-100). Of ACL-reconstructed knees, 41 (50%) had radiographic OA, of which 6 (7.3%) had severe OA (KL III). Of the contralateral healthy knees, 28 (34.1%) had radiographic evidence of OA. Of these 22 (26.8%) and 6 (7.3%) patients had, respectively, KL-I and KL-II. 11 patients (11.8%) underwent subsequent knee surgery: 5 (5.4%) revisions, 3 (3.2%) meniscal surgeries, 2 (2.2%) other surgeries, 1 (1.1%) contralateral ACL reconstruction.

CONCLUSIONS

The study demonstrates that ACL reconstruction with HT autograft and cortico-cancellous screw suspension device determines satisfying clinical results after 10 years of follow-up. From our cohort, a low rate of graft failure has been reported, even though almost 50% of patients present a knee OA greater or equal to grade II KL.

Prevalence of post-traumatic osteoarthritis after anterior cruciate ligament injury remains high despite advances in surgical techniques

Aims

The aim of this study was to report the pooled prevalence of post-traumatic osteoarthritis (PTOA) and examine whether the risk of developing PTOA after anterior cruciate ligament (ACL) injury has decreased in recent decades.

Methods

The PubMed and Web of Science databases were searched from 1 January 1980 to 11 May 2022. Patient series, observational studies, and clinical trials having reported the prevalence of radiologically confirmed PTOA after ACL injury, with at least a ten-year follow-up, were included. All studies were analyzed simultaneously, and separate analyses of the operative and nonoperative knees were performed. The prevalence of PTOA was calculated separately for each study, and pooled prevalence was reported with 95% confidence intervals (CIs) using either a fixed or random effects model. To examine the effect of the year of injury on the prevalence, a logit transformed meta-regression analysis was used with a maximum-likelihood estimator. Results from meta-regression analyses were reported with the unstandardized coefficient (β).

Results

The pooled prevalence of PTOA was 37.9% (95% CI 32.1 to 44) for operatively treated ACL injuries with a median follow-up of 14.6 years (interquartile range (IQR) 10.6 to 16.7). For nonoperatively treated ACL injuries, the prevalence was 40.5% (95% CI 28.9 to 53.3), with a median of follow-up of 15 years (IQR 11.7 to 20.0). The association between the year of operation and the prevalence of PTOA was weak and imprecise and not related to the choice of treatment (operative β -0.038 (95% CI -0.076 to 0.000) and nonoperative β -0.011 (95% CI -0.101 to 0.079)).

Conclusion

The initial injury, irrespective of management, has, by the balance of probability, resulted in PTOA within 20 years. In addition, the prevalence of PTOA has only slightly decreased during past decades. Therefore, further research is warranted to develop strategies to prevent the development of PTOA after ACL injuries.

Knee Extensor Mechanism Complications After Autograft Harvest in ACL Reconstruction: A Systematic Review and Meta-analysis

Background

Existing systematic reviews have sought to characterize the relative donor-site morbidity of bone-patellar tendon-bone (BTB) and quadriceps tendon (QT) grafts after anterior cruciate ligament reconstruction (ACLR). However, no studies have reported the pooled proportions of patellar fractures and donor tendon ruptures across the body of literature.

Purpose

To estimate the proportion of patellar fractures, patellar tendon ruptures, and QT ruptures associated with BTB or QT autograft harvest during ACLR using published data.

Study Design

Systematic review; Level of evidence, 4.

Methods

A meta-analysis was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using 3 online databases (PubMed, Scopus, and Web of Science). A total of 800 manuscripts were included in the initial research of peer-reviewed articles in English that reported extensor mechanism complications associated with graft harvest in patients after ACLR. Pooled proportions of patellar fractures, patellar tendon ruptures, and QT ruptures were calculated for each graft type (BTB, QT) using a random-effects model for meta-analysis.

Results

A total of 28 studies were analyzed. The pooled proportion of patellar fractures was 0.57% (95% CI, 0.34%-0.91%) for the BTB harvest and 2.03% (95% CI, 0.78%-3.89%) for the QT harvest. The proportion of patellar tendon ruptures was 0.22% (95% CI, 0.14%-0.33%) after the BTB harvest, and the proportion of QT ruptures was 0.52% (95% CI, 0.06%-1.91%) after the QT harvest. The majority of included studies (16/28 [57.1%]) had an evidence level of 4.

Conclusion

Based on the current literature, the proportion of extensor mechanism complications after ACLR using either a BTB or a QT autograft is low, indicating that the extensor mechanism harvest remains a safe option. A higher proportion of patellar fractures was noted for QT grafts and a higher proportion of donor tendon ruptures was noted for QT grafts compared with BTB grafts.

Low Femoral Tunnel Widening Incidence Rate After ACL Reconstruction Using Patellar Tendon Graft with Press-Fit Fixation

Background

Femoral tunnel widening after ACL reconstruction is a common phenomenon. We hypothesized that using a patellar tendon graft with a press-fit fixation technique without any fixation device reduces the incidence of femoral tunnel widening.

Methods

This study was conducted on 467 patients with ACL surgery between 2003 and 2015. Two hundred and nineteen of them had an ACL surgery with patellar tendon (PT) graft, and two hundred and forty-eight of them with hamstring tendon (HS). Exclusion criteria were history of previous ACL reconstruction of either knee, multiple ligament injury, or evidence of osteoarthritis on radiographs. The femoral tunnels were measured on the anteroposterior (ap) and lateral radiographs 6 months after the operation. Two independent orthopedic surgeons measured all radiographs twice and recorded the tunnel widenings. We hypothesized that using an implant-free press-fit technique with PT graft can reduce the femoral tunnel widening incidence rate.

Results

The mean incidence rate of the tunnel widening in the HS group was, on the AP and the lateral femoral views, 88% (n = 217) and 83% (n = 205), while in the PT group, 17% (n = 37) and 2% (n = 4), respectively. There was a significant difference both on AP and lateral radiographs (HS vs. PT: fem. AP: 89% vs. 17% p < 0.001; HS vs. PT: fem. lat: 84% vs. 2% p < 0.001).

Conclusion

The femoral tunnel widening incidence rate during an ACL reconstruction is significantly less when using PT tendon with femoral press-fit fixation than when using HT tendon with suspensory fixation method.

All-Soft Tissue Quadriceps Tendon Autograft in Revision Anterior Cruciate Ligament Reconstruction in Athletes: Comparison to Bone-Patellar Tendon-Bone Autograft With at Least a 2-Year Follow-up

BACKGROUND

Revision anterior cruciate ligament (ACL) reconstruction is being performed at an increasing rate. Previous literature has suggested that autograft ACL reconstruction is a better option than allograft in revision surgery, although the optimal autograft choice remains unknown. The all-soft tissue quadriceps tendon (ASTQT) autograft has been found to be an effective option for primary ACL reconstruction. However, few studies have evaluated ASTQT autograft in revision ACL reconstruction.

PURPOSE/HYPOTHESIS

The purpose of this study was to evaluate the ASTQT autograft in revision ACL reconstruction in athletes compared with bone-patellar tendon-bone (BTB) autograft. We hypothesized that the ASTQT autograft would lead to similar return to play, time to return to play, retear rate, and patient-reported outcomes compared with BTB autograft.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective study was performed on all athletes undergoing revision ACL reconstruction between August 2013 and December 2019 at a single institution. Patients participating in high school or college athletics undergoing first-time revision with either ASTQT or BTB autograft with ≥2 years of follow-up were included. Demographic variables, complications, return to sports, and outcome scores including the International Knee Documentation Committee (IKDC) and Lysholm were collected and compared between the 2 cohorts.

RESULTS

A total of 58 revision ACL reconstructions were included, with 32 in the ASTQT cohort and 26 in the BTB cohort. Return to sports at the same level occurred in 62.5% of the ASTQT group and 53.8% of the BTB group. The ASTQT group returned to sports significantly faster than the BTB group (8.9 vs 10.3 months; P = .020). There was no difference in retear rates (3.1%, ASTQT; 7.7%, BTB) or other complications between the 2 groups. The IKDC scores were significantly higher at the 6- and 12-month follow-up for the ASTQT autograft group compared with the BTB group (6 months: ASTQT, 71.3; BTB, 61.7, P = .001; 12 months: ASTQT, 82.7; BTB, 78.6; P = .021). Lysholm scores were also greater in the ASTQT cohort at these time points (6 months: ASTQT, 75.1; BTB, 63.6; P < .001; 12 months: ASTQT, 82.0; BTB, 74.5; P < .001). However, IKDC and Lysholm scores were similar between both groups at final follow-up (IKDC: ASTQT, 82.9; BTB, 81.7; P = .344; Lysholm: ASTQT, 83.0; BTB, 81.0; P = .104) There was no significant clinical difference in the absolute difference in scores or rate of achieving clinical thresholds between the 2 cohorts.

CONCLUSION

ASTQT autograft for revision ACL in athletes has similar outcomes compared with BTB autograft. However, the ASTQT may possibly afford quicker return to sports and better early improvements in patient-reported outcomes that normalize by 1 year. The soft tissue quadriceps autograft should be considered a viable graft option in revision ACL reconstruction in athletes.

Knee osteoarthritis, joint laxity and PROMs following conservative management versus surgical reconstruction for ACL rupture: a meta-analysis

INTRODUCTION

Patients whose rupture of the anterior cruciate ligament (ACL) can be managed conservatively or undergo reconstruction surgery.

SOURCE OF DATA

Current scientific literature published in Web of Science, PubMed and Scopus.

AREAS OF AGREEMENT

Several studies published by July 2022 compare surgical and conservative management following ACL rupture. The latest evidence suggests that surgical management may expose patients to an increased risk of early-onset knee osteoarthritis (OA).

AREAS OF CONTROVERSY

The state of art does not recommend a systematic ACL reconstruction to all patients who tore their ACL. After the initial trauma, surgical reconstruction may produce even greater damage to the intra-articular structures compared to conservative management.

GROWING POINTS

The state of art does not recommend systematic surgical reconstruction to all patients who tore their ACL. The present study compared surgical reconstruction versus conservative management for primary ACL ruptures in terms of joint laxity, patient reported outcome measures (PROMs) and rate of osteoarthritis.

AREAS TIMELY FOR DEVELOPING RESEARCH

ACL reconstruction provides significant improvement in joint laxity compared to conservative management, but is associated with a significantly greater rate of knee osteoarthritis, despite similar results at PROM assessment.

Biomechanical evaluation of an allograft fixation system for ACL reconstruction

The purpose of this study was to compare the biomechanical stability, especially graft slippage of an allograft screw and a conventional interference screw for tibial implant fixation in ACL reconstruction. Twenty-four paired human proximal tibia specimens underwent ACL reconstruction, with the graft in one specimen of each pair fixed using the allograft screw and the other using the conventional interference screw. Specimens were subjected to cyclic tensile loading until failure. The two fixation methods did not show any statistical difference in load at graft slippage (p = 0.241) or estimated mean survival until slippage onset (p = 0.061). The ultimate load and the estimated mean survival until failure were higher for the interference screw (p = 0.04, and p = 0.018, respectively). Graft displacement at ultimate load reached values of up to 7.2 (interference screw) and 11.3 mm (allograft screw). The allograft screw for implant fixation in ACL reconstruction demonstrated comparable behavior in terms of graft slippage to the interference screw but underperformed in terms of ultimate load. However, the ultimate load, occurring at progressive graft slippage, may not be considered a direct indicator of clinical failure.

Bone plug fixation in anterior cruciate ligament reconstruction: A clinical and radiological assessment of graft-tunnel integration

BACKGROUND

The decision regarding graft choice and fixation in anterior cruciate ligament (ACL) reconstruction remains controversial. Free cylindrical bone plugs have been used successfully as graft fixation method. However, some concerns continue to exist regarding how well these plugs integrate with the bony walls of the tunnel. The aim of this study was to assess osteo-integration of free cylindrical bone plugs and to evaluate its effect on the clinical outcomes of the procedure.

METHODS

From January 2015 to December 2017, 30 patients (21-40 years old) with torn ACL were operated on and followed up for 24 months after surgery. All patients were assessed clinically (International Knee Documentation Committee score (IKDC) and Tegner-Lysholm knee scoring system), instrumentally (KT 1000 and Rolimeter), and radiologically (X-ray, computed tomography and magnetic resonance imaging). Young active patients with torn ACL were included while those with previous ligamentous injury and/or surgery were excluded.

RESULTS

All bone grafts showed solid bone healing after 6 months of surgery; incorporation was 'good to excellent' (tibial side: 66.6%; femoral side: 86.6%). There was no correlation between age or time interval and graft incorporation. Positive correlation was shown between tibial and femoral graft incorporation within the same patient. Only one patient was abnormal in our final objective IKDC scores (graded C). The mean side-to-side difference with KT 1000 and Rolimeter was 1.9 and 1.8, respectively.

CONCLUSION

Free cylindrical bone plugs could be used safely for hamstring tendon graft fixation; it enhances graft tunnel integration within the first 6 months and yields comparable clinical outcomes whilst avoiding the potential hazards of foreign hardware implants.

Functional Ultra-High Molecular Weight Polyethylene Composites for Ligament Reconstructions and Their Targeted Applications in the Restoration of the Anterior Cruciate Ligament

The selection of biomaterials as biomedical implants is a significant challenge. Ultra-high molecular weight polyethylene (UHMWPE) and composites of such kind have been extensively used in medical implants, notably in the bearings of the hip, knee, and other joint prostheses, owing to its biocompatibility and high wear resistance. For the Anterior Cruciate Ligament (ACL) graft, synthetic UHMWPE is an ideal candidate due to its biocompatibility and extremely high tensile strength. However, significant problems are observed in UHMWPE based implants, such as wear debris and oxidative degradation. To resolve the issue of wear and to enhance the life of UHMWPE as an implant, in recent years, this field has witnessed numerous innovative methodologies such as biofunctionalization or high temperature melting of UHMWPE to enhance its toughness and strength. The surface functionalization/modification/treatment of UHMWPE is very challenging as it requires optimizing many variables, such as surface tension and wettability, active functional groups on the surface, irradiation, and protein immobilization to successfully improve the mechanical properties of UHMWPE and reduce or eliminate the wear or osteolysis of the UHMWPE implant. Despite these difficulties, several surface roughening, functionalization, and irradiation processing technologies have been developed and applied in the recent past. The basic research and direct industrial applications of such material improvement technology are very significant, as evidenced by the significant number of published papers and patents. However, the available literature on research methodology and techniques related to material property enhancement and protection from wear of UHMWPE is disseminated, and there is a lack of a comprehensive source for the research community to access information on the subject matter. Here we provide an overview of recent developments and core challenges in the surface modification/functionalization/irradiation of UHMWPE and apply these findings to the case study of UHMWPE for ACL repair.

An older age, a longer duration between injury and surgery, and positive pivot shift test results increase the prevalence of articular cartilage injury during ACL reconstruction in all three compartments of the knee in patients with ACL injuries

PURPOSE

To investigate factors that influence the prevalence of articular cartilage injury in patients with anterior cruciate ligament (ACL) injury.

METHODS

This multicentre study included patients with ACL injury. Logistic regression analysis was conducted to identify factors that influence the prevalence of cartilage injury during ACL reconstruction.

RESULTS

A total of 811 patients were enrolled. The factors that significantly influenced the prevalence of cartilage injury were age (odds ratio [OR], 1.04; P = 0.000), a positive pivot shift test result (OR, 1.43; P = 0.021), medial meniscal injury (OR, 2.55; P = 0.000), and delayed surgery (≥ 12 months) (OR, 2.52; P = 0.028) in the medial compartment of the knee; age (OR, 1.05; P = 0.000), subjective grades of apprehension during the pivot shift test (OR, 1.46; P = 0.010), lateral meniscal injury (OR, 1.98; P = 0.003), femoro-tibial angle (FTA) (OR, 0.92; P = 0.006), and delayed surgery (≥ 12 months) (OR, 2.63; P = 0.001) in the lateral compartment; and age (OR, 1.06; P = 0.000), body mass index (OR, 1.07; P = 0.028), a positive pivot shift test result (OR, 1.60; P = 0.018), FTA (OR, 0.90; P = 0.006), and delayed surgery (≥ 12 months) (OR, 3.17; P = 0.008) in the patellofemoral compartment.

CONCLUSION

An older age, a longer duration between injury and surgery, and a positive pivot shift test result were positively associated with the prevalence of cartilage injury in three compartments in patients with ACL injuries. Early ACL reconstruction is recommended to prevent cartilage injury.

LEVEL OF EVIDENCE

Level III.

Comparing Knee Laxity After Anatomic Anterior Cruciate Ligament Reconstruction Using Quadriceps Tendon Versus Semitendinosus Tendon Graft

Background:

The choice of graft in anterior cruciate ligament (ACL) reconstruction is still under discussion. The hamstrings are currently the most used grafts for primary ACL reconstruction in Europe. However, increased interest has arisen in the quadriceps tendon (QT) as an alternative autologous graft option for primary ACL reconstruction.

Purpose:

To evaluate knee stability and the subjective outcome after ACL reconstruction using either autologous QT graft in implant-free femoral press-fit fixation technique or semitendinosus tendon (ST) graft.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

We evaluated 50 patients who underwent ACL reconstruction, including 25 patients who received autologous ipsilateral QT graft (QT group) and 25 patients who received the ipsilateral ST graft (ST group). The follow-up for this prospective comparative study was at least 2 years after surgery, comprising KT-1000 arthrometer testing, pivot-shift test, Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm score, and rerupture rate.

Results:

The mean patient age was 31.72 years (9 women, 16 men) in the QT group and 32.08 years (13 women, 12 men) in the ST group. The mean ± standard deviation postoperative side-to-side difference assessed using KT-1000 arthrometer was 1.56 ± 1.56 mm for the QT group and 1.64 ± 1.41 mm for the ST group, with no significant difference. No significant difference was found on any of the KOOS subscale scores (P = .694) or the Lysholm score (P = .682). No rerupture or positive pivot-shift test occurred during follow-up. No difference was found in donor-site morbidity between the study groups.

Conclusion:

Clinical outcomes were not significantly different between QT and ST grafts in the current study. Thus, the QT may serve as a good alternative graft for primary ACL reconstruction.

Treatment after anterior cruciate ligament injury: Panther Symposium ACL Treatment Consensus Group

Treatment strategies for anterior cruciate ligament (ACL) injuries continue to evolve. Evidence supporting best practice guidelines for the management of ACL injury is to a large extent based on studies with low-level evidence. An international consensus group of experts was convened to collaboratively advance towards consensus opinions regarding the best available evidence on operative versus non-operative treatment for ACL injury.The purpose of this study was to report the consensus statements on operative versus non-operative treatment of ACL injuries developed at the ACL Consensus Meeting Panther Symposium 2019. Sixty-six international experts on the management of ACL injuries, representing 18 countries, convened and participated in a process based on the Delphi method of achieving consensus. Proposed consensus statements were drafted by the Scientific Organising Committee and Session Chairs for the three working groups. Panel participants reviewed preliminary statements prior to the meeting and provided initial agreement and comments on the statement via online survey. During the meeting, discussion and debate occurred for each statement, after which a final vote was then held. Eighty per cent agreement was defined a priori as consensus. A total of 11 of 13 statements on operative veresus non-operative treatment of ACL injury reached consensus during the symposium. Nine statements achieved unanimous support; two reached strong consensus; one did not achieve consensus; and one was removed due to redundancy in the information provided.In highly active patients engaged in jumping, cutting and pivoting sports, early anatomical anterior cruciate ligament reconstruction (ACLR) is recommended due to the high risk of secondary meniscus and cartilage injuries with delayed surgery, although a period of progressive rehabilitation to resolve impairments and improve neuromuscular function is recommended. For patients who seek to return to straight plane activities, non-operative treatment with structured, progressive rehabilitation is an acceptable treatment option. However, with persistent functional instability or when episodes of giving way occur, anatomical ACLR is indicated. The consensus statements derived from international leaders in the field will assist clinicians in deciding between operative and non-operative treatment with patients after an ACL injury.Level of evidence: V.

Recent Trends in Concomitant Meniscal Procedures During Anterior Cruciate Ligament Reconstruction

BACKGROUND

The chondroprotective effect and secondary stabilizing role of the meniscus has been well-established. Meniscal preservation during anterior cruciate ligament reconstruction (ACLR) has been advocated in the literature and supported by advancements in surgical techniques.

PURPOSE

To examine the recent trends in concomitant partial meniscectomy and meniscal repair procedures with ACLR.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Patients who underwent arthroscopic meniscectomy (Current Procedural Terminology [CPT] codes 29880, 29881), meniscal repair (CPT codes 29882, 29883), and ACLR (CPT code 29888) between 2010 and 2018 were identified using the National Surgical Quality Improvement Program database. We calculated the proportion of patients who underwent each surgery type, stratified by year and by patient age and body mass index (BMI) groups. The Cochran-Armitage test for trend was used to analyze yearly proportions of concomitant meniscal surgery types.

RESULTS

During the 9-year study period, 22,760 patients underwent either isolated ACLR (n = 10,562) or ACLR with concomitant meniscal surgery (either meniscectomy [n = 8931] or meniscal repair [n = 3267]). There was a gradual decrease in the proportion of meniscectomies (from 80.8% of concomitant procedures in 2010 to 63.8% in 2018), while the proportion of meniscal repairs almost doubled (from 19.2% in 2010 to 36.2% in 2018) (trend, P < .001). ACLR with meniscal repair increased in patients aged 35 to 44 years and 45 to 54 years (trend, P = .027) between 2010 and 2018; at the same time, the proportion of normal weight patients decreased by 17.7%, the proportion of overweight patients increased by 13.2%, and increases were seen in BMI groups corresponding to obesity classes 1 to 3 (trend, P < .001). In 2010, the average BMI of patients undergoing ACLR with meniscectomy versus meniscal repair differed by 2 (P = .004), but by 2018 the difference was nonsignificant (28.83 ± 5.80 vs 28.53 ± 5.73; P = .113).

CONCLUSION

Between 2010 and 2018, there was an upward trend in the proportion of meniscal repairs performed during ACLR, with notable increases in the proportion of repairs being performed on older, overweight, and obese patients.

Risk of overconstraining femorotibial rotation after anatomical ACL reconstruction using bone patella tendon bone autograft

INTRODUCTION

Numerous studies have focused on the anteroposterior stability after anterior cruciate ligament (ACL) reconstruction, with less emphasis on rotational stability. It has been hypothesized that bone patella tendon bone (BTB) autograft for ACL reconstruction restores knee rotation closely to normal due to its comparable fiber orientation to the native ACL.

MATERIALS AND METHODS

Twenty patients with unilateral ACL rupture and an uninjured contralateral knee were included in this study. The ACL was reconstructed using the medial third of the patellar tendon. Tunnel placement was controlled by fluoroscopy. Implant-free press-fit graft fixation was used on both femoral and tibial side. Bone blocks were carefully placed to restore fiber orientation of both the anteromedial and posterolateral bundle, similar to the native ACL. Rotatory laxity of both knees was measured at 0° and 25° of flexion pre- and post-surgery, using an active opto-electronical motion-analysis system (LUKOTRONIC AS 100^®). All measurements were performed under general anesthesia during surgery.

RESULTS

Knee rotation was reduced significantly in both 0°and 25° of flexion following ACL reconstruction (p < 0.001). The side to side difference (SSD) of the rotatory laxity in extension was greater in the ACL-deficient knee (14.9° ± 8.9°), but decreased significantly after ACL reconstruction (- 5.9° ± 7.7°, minus value means less than in the uninjured knee). There was a similar finding at 25° of knee flexion where greater rotation of the ACL-deficient knee (5.7° ± 10.3°) prior to surgery changed to lower degree of rotation after surgery (- 11.3° ± 8.4°) in comparison to the uninjured knee.

CONCLUSIONS

ACL reconstruction with a BTB graft in anatomical position using press-fit implant-free fixation is able to restore rotatory knee stability close to the intact contralateral knee. Despite the fact that the BTB graft offers fiber orientation close to the natural ACL, the surgeon should be aware of the potential risk of over-constraining the knee in terms of rotation.

LEVEL OF EVIDENCE

II.

Recent advances in 3D bioprinting of musculoskeletal tissues

The musculoskeletal system is essential for maintaining posture, protecting organs, facilitating locomotion, and regulating various cellular and metabolic functions. Injury to this system due to trauma or wear is common, and severe damage may require surgery to restore function and prevent further harm. Autografts are the current gold standard for the replacement of lost or damaged tissues. However, these grafts are constrained by limited supply and donor site morbidity. Allografts, xenografts, and alloplastic materials represent viable alternatives, but each of these methods also has its own problems and limitations. Technological advances in three-dimensional (3D) printing and its biomedical adaptation, 3D bioprinting, have the potential to provide viable, autologous tissue-like constructs that can be used to repair musculoskeletal defects. Though bioprinting is currently unable to develop mature, implantable tissues, it can pattern cells in 3D constructs with features facilitating maturation and vascularization. Further advances in the field may enable the manufacture of constructs that can mimic native tissues in complexity, spatial heterogeneity, and ultimately, clinical utility. This review studies the use of 3D bioprinting for engineering bone, cartilage, muscle, tendon, ligament, and their interface tissues. Additionally, the current limitations and challenges in the field are discussed and the prospects for future progress are highlighted.

Treatment after ACL injury: Panther Symposium ACL Treatment Consensus Group

Treatment strategies for ACL injuries continue to evolve. Evidence supporting best practice guidelines to manage ACL injury is largely based on studies with low-level evidence. An international consensus group of experts was convened determine consensus regarding best available evidence on operative versus non-operative treatment for ACL injury. The purpose of this study is to report the consensus statements on operative versus non-operative treatment of ACL injuries developed at the ACL Consensus Meeting Panther Symposium 2019. Sixty-six international experts on the management of ACL injuries, representing 18 countries, convened and participated in a process based on the Delphi method of achieving consensus. Proposed consensus statements were drafted by the Scientific Organising Committee and Session Chairs. Panel participants reviewed preliminary statements prior to the meeting and provided initial agreement and comments on the statement via online survey. During the meeting, discussion and debate occurred for each statement, after which a final vote was then held. Eighty per cent agreement was defined a priori as consensus. A total of 11 of 13 statements on operative versus non-operative treatment of ACL injury reached consensus during the Symposium. Nine statements achieved unanimous support, two reached strong consensus, one did not achieve consensus, and one was removed due to redundancy in the information provided. In highly active patients engaged in jumping, cutting and pivoting sports, early anatomical ACL reconstruction is recommended due to the high risk of secondary meniscus and cartilage injuries with delayed surgery, although a period of progressive rehabilitation to resolve impairments and improve neuromuscular function is recommended. For patients who seek to return to straight plane activities, non-operative treatment with structured, progressive rehabilitation is an acceptable treatment option. However, with persistent functional instability, or when episodes of giving way occur, anatomical ACL reconstruction is indicated. The consensus statements derived from international leaders in the field may assist clinicians in deciding between operative and non-operative treatment with patients after an ACL injury. Level of evidence: Level V

Treatment After Anterior Cruciate Ligament Injury: Panther Symposium ACL Treatment Consensus Group

Treatment strategies for anterior cruciate ligament (ACL) injuries continue to evolve. Evidence supporting best-practice guidelines for the management of ACL injury is to a large extent based on studies with low-level evidence. An international consensus group of experts was convened to collaboratively advance toward consensus opinions regarding the best available evidence on operative versus nonoperative treatment for ACL injury. The purpose of this study was to report the consensus statements on operative versus nonoperative treatment of ACL injuries developed at the ACL Consensus Meeting Panther Symposium 2019. There were 66 international experts on the management of ACL injuries, representing 18 countries, who were convened and participated in a process based on the Delphi method of achieving consensus. Proposed consensus statements were drafted by the scientific organizing committee and session chairs for the 3 working groups. Panel participants reviewed preliminary statements before the meeting and provided initial agreement and comments on the statement via online survey. During the meeting, discussion and debate occurred for each statement, after which a final vote was then held. Ultimately, 80% agreement was defined a priori as consensus. A total of 11 of 13 statements on operative versus nonoperative treatment of ACL injury reached consensus during the symposium. Overall, 9 statements achieved unanimous support, 2 reached strong consensus, 1 did not achieve consensus, and 1 was removed because of redundancy in the information provided. In highly active patients engaged in jumping, cutting, and pivoting sports, early anatomic ACL reconstruction is recommended because of the high risk of secondary meniscal and cartilage injuries with delayed surgery, although a period of progressive rehabilitation to resolve impairments and improve neuromuscular function is recommended. For patients who seek to return to straight-plane activities, nonoperative treatment with structured, progressive rehabilitation is an acceptable treatment option. However, with persistent functional instability, or when episodes of giving way occur, anatomic ACL reconstruction is indicated. The consensus statements derived from international leaders in the field will assist clinicians in deciding between operative and nonoperative treatment with patients after an ACL injury.

Anatomic ACL reconstruction reduces risk of post-traumatic osteoarthritis: a systematic review with minimum 10-year follow-up

PURPOSE

To systematically review the literature for radiographic prevalence of osteoarthritis (OA) at a minimum of 10 years following anterior cruciate ligament (ACL) reconstruction (ACLR) with anatomic vs. non-anatomic techniques. It was hypothesized that the incidence of OA at long-term follow-up would be lower following anatomic compared to non-anatomic ACLR.

METHODS

A systematic review was performed by searching PubMed, MEDLINE, EMBASE, and the Cochrane Library, for studies reporting OA prevalence by radiographic classification scales at a minimum of 10 years following ACLR with autograft. Studies were categorized as anatomic if they met or exceeded a score of 8 according the Anatomic ACL Reconstruction Scoring Checklist (AARSC), while those with a score less than 8 were categorized as non-anatomic/non-specified. Secondary outcomes included graft failure and measures of knee stability (KT-1000, Pivot Shift) and functional outcomes [Lysholm, Tegner, subjective and objective International Knee Documentation Committee (IKDC) scores]. OA prevalence on all radiographic scales was recorded and adapted to a normalized scale.

RESULTS

Twenty-six studies were included, of which 5 achieved a score of 8 on the AARSC. Using a normalized OA classification scale, 87 of 375 patients (23.2%) had diagnosed OA at a mean follow-up of 15.3 years after anatomic ACLR and 744 of 1696 patients (43.9%) had OA at mean follow-up of 15.9 years after non-anatomic/non-specified ACLR. The AARSC scores were 9.2 ± 1.3 for anatomic ACLR and 5.1 ± 1.1 for non-anatomic/non-specified ACLR. Secondary outcomes were relatively similar between techniques but inconsistently reported.

CONCLUSIONS

This study showed that anatomic ACLR, defined as an AARSC score ≥ 8, was associated with lower OA prevalence at long-term follow-up. Additional studies reporting long-term outcomes following anatomic ACLR are needed, as high-level studies of anatomic ACLR are lacking. The AARSC is a valuable resource in performing and evaluating anatomic ACLR. Anatomic ACLR, as defined by the AARSC, may reduce the long-term risk of post-traumatic OA following ACL injury to a greater extent than non-anatomic ACLR.

LEVEL OF EVIDENCE

IV.

Treatment after anterior cruciate ligament injury: Panther Symposium ACL Treatment Consensus Group

Treatment strategies for anterior cruciate ligament (ACL) injuries continue to evolve. Evidence supporting best practice guidelines for the management of ACL injury is to a large extent based on studies with low-level evidence. An international consensus group of experts was convened to collaboratively advance toward consensus opinions regarding the best available evidence on operative vs. non-operative treatment for ACL injury. The purpose of this study is to report the consensus statements on operative vs. non-operative treatment of ACL injuries developed at the ACL Consensus Meeting Panther Symposium 2019. Sixty-six international experts on the management of ACL injuries, representing 18 countries, were convened and participated in a process based on the Delphi method of achieving consensus. Proposed consensus statements were drafted by the Scientific Organizing Committee and Session Chairs for the three working groups. Panel participants reviewed preliminary statements prior to the meeting and provided the initial agreement and comments on the statement via an online survey. During the meeting, discussion and debate occurred for each statement, after which a final vote was then held. Eighty percent agreement was defined a-priori as consensus. A total of 11 of 13 statements on operative v. non-operative treatment of ACL injury reached the consensus during the Symposium. Nine statements achieved unanimous support, two reached strong consensus, one did not achieve consensus, and one was removed due to redundancy in the information provided. In highly active patients engaged in jumping, cutting, and pivoting sports, early anatomic ACL reconstruction is recommended due to the high risk of secondary meniscus and cartilage injuries with delayed surgery, although a period of progressive rehabilitation to resolve impairments and improve neuromuscular function is recommended. For patients who seek to return to straight plane activities, non-operative treatment with structured, progressive rehabilitation is an acceptable treatment option. However, with persistent functional instability, or when episodes of giving way occur, anatomic ACL reconstruction is indicated. The consensus statements derived from international leaders in the field will assist clinicians in deciding between operative and non-operative treatments with patients after an ACL injury.Level of evidence V.

Quadriceps tendon vs. patellar tendon autograft for ACL reconstruction using a hardware-free press-fit fixation technique: comparable stability, function and return-to-sport level but less donor site morbidity in athletes after 10 years

INTRODUCTION

The use of quadriceps tendon-patellar bone (QTB) autograft for anterior cruciate ligament (ACL) reconstruction is gaining momentum. Yet, long-term results that compare this procedure with established methods are lacking. The aim of this study was to report and compare long-term results of ACL reconstruction using QTB autografts versus bone-patellar tendon-bone (BPTB) autografts, both anchored using a hardware-free press-fit fixation technique.

MATERIALS AND METHODS

60 athletes (Tegner score ≥6) with primary ACL rupture were prospectively randomized into two groups. 56 patients were evaluated after a mean duration of 12.2 ± 1.9 months (range 10-14) and 43 patients after 10.3 ± 0.2 years (range 10-11).

RESULTS

On final follow-up, 90% of patients scored very good and good results in the functional Lysholm score (mean 99 ± 7.1, range 74-100 points). Normal or almost normal IKDC score was reported by 84% of the patients (mean 97 ± 9.5, range 60-100 points). The activity level decreased in the Tegner score from median of 7 before injury to 6 after 10 years. The KT-1000 arthrometer showed a difference in the anterior translation of less than 3 mm (mean 1.0 ± 1.2, range - 1 to 5 mm) in 91% of the patients. Significant degeneration was radiologically detected in one patient per group. No tunnel widening was seen in any patient. Up to 97% of all patients were satisfied with the operative procedure. No significant differences were found in the mentioned parameters between the two groups and also in comparison with the 1-year results. The only significant difference was in the donor site morbidity. Significantly more patients in the BPTB group had complaints during kneeling both at 1 (p < 0.001) and 10 years (p = 0.019). Squatting was also subjectively more problematic in the BPTB group than in the QTB group both after 1 (p = 0.003) and 10 years (p = 0.046).

CONCLUSIONS

This study shows equally good functional, clinical and radiological long-term results for both hardware-free methods of ACL reconstruction. These results clinically confirm the safety of press-fit anchoring after 10 years. The failure rate in this study was very low, with only one re-rupture in 10 years. The increased donor site morbidity when using the BPTB autograft compared to the QTB autograft supports already reported data. It was also seen in this study for the implant-free press-fit techniques.

STUDY DESIGN

Prospective and randomized, level of evidence 2.

The effect of a longitudinal tear of the medial meniscus on medial meniscal extrusion in anterior cruciate ligament injury patients

PURPOSE

The purpose of this study was to investigate the effect of a longitudinal tear of the medial meniscus (MM) and its meniscal repair on MM extrusion in anterior cruciate ligament (ACL)-injured patients. The hypothesis underlying this study was that a longitudinal tear of the MM is correlated with MM extrusion, and that the extrusion would persist after ACL reconstruction with concomitant MM repair.

METHODS

Forty-three ACL-injured patients with a concomitant MM longitudinal tear were included in the MM tear group. Thirty-four solely ACL-injured patients without any meniscal injuries were included in the Control group. Medial meniscus extrusion width (MEW) was measured pre-operatively and three months after surgery on magnetic resonance imaging.

RESULTS

Pre-operative MEW in the MM tear group was significantly larger than that in the Control group (MM tear group: 1.5 mm, Control: 0.3 mm, P < 0.001). The MEW change in the MM tear group was significantly greater than that in the Control group three months after operation (MM tear group: 0.8 mm, Control: -0.2 mm, P < 0.001). The number of sutures required for repair was correlated with MEW both pre-operatively and postoperatively in the MM tear group (pre-operative: P = 0.005, R = 0.42, postoperative: P < 0.001, R = 0.54).

CONCLUSION

Longitudinal tear of the MM was correlated with MM extrusion and the MM extrusion persisted after ACL reconstruction with concomitant MM repair in the MM tear group. The initial meniscal tear size was directly correlated with the pre-operative MEW. Therefore, meniscal extrusion after longitudinal tears of the medial meniscus should be taken into careful consideration.

Prevalence of patellofemoral joint osteoarthritis after anterior cruciate ligament injury and associated risk factors: A systematic review

Background

The prevalence of patellofemoral joint (PFJ) osteoarthritis (OA) after anterior cruciate ligament (ACL) injury was inconsistently reported in the literature. This review summarises the reported prevalence of PFJ OA and risk factors of PFJ OA after ACL injury.

Methods

PubMed, Embase, WoS, and MEDLINE (OVID) were searched up to 1 March 2019. A modified version of the Coleman methodology score was used to assess the methodological quality of the included studies. Prevalence of PFJ OA was pooled depended on different interventions in ACL injured populations.

Results

Thirty-eight studies were included. Five different radiographic classification methods were used: the Kellgren and Lawrence Grade 2, IKDC Grade B, Fairbank Grade 1, joint space narrowing of Grade 2 based on OARSI, and Ahlbäck Grade 1. One included study used MRI Osteoarthritis Knee Score to evaluate PFJ degenerative changes. The overall prevalence of PFJ OA after ACL injury in included studies varied between 4.5% and 80%. The large variation of PFJ OA prevalence is mainly because of different follow-up period and surgical techniques. The pooled data showed that bone-patellar tendon-bone graft, single-bundle ACL reconstruction (ACLR), and delayed ACLR are likely associated with PFJ degenerative changes after ACL injury. ACLR, delayed ACLR, body mass index (BMI), meniscectomy, patellofemoral chondral lesions, age at surgery, and TFJ OA were identified in the literature inducing PFJ OA after ACL injury.

Conclusions

Large variations of PFJ OA after ACL injury are associated with different follow-up period and surgical techniques. ACL reconstructed population with bone-patellar tendon-bone graft, single-bundle reconstruction, and delayed operation time has a high prevalence of PFJ OA.

The translational potential of this article

This review focuses more on the effect of surgical technique factors on the degenerative changes on PFJ. The results reveal that BPTB, single-bundle reconstruction, and delayed ACLR are more likely associated with PFJ degenerative changes after ACL injury. These findings imply that awareness of PFJ problems after surgical intervention will remind of surgeons taking PFJ into consideration in operations, which is likely to reduce the incidences of anterior knee pain, patellar maltracking, and over-constrained patella in the early stage after surgery.

ACL reconstruction with quadriceps tendon graft and press-fit fixation versus quadruple hamstring graft and interference screw fixation - a matched pair analysis after one year follow up

Background

The objective of the study was to compare the results of a primary anterior cruciate ligament reconstruction (ACLR) using the press-fit fixation technique for a quadriceps tendon (QT) graft to a standard quadrupled hamstring (HT) graft with interference screw fixation.

Methods

A retrospective cohort study with a 12-month follow up provided data for 92 patients. Exclusion criteria were accompanying ligament injuries and contralateral ACL injury. Patients who suffered a graft failure, which was defined as a side-to-side difference of > 3 mm, or infection were rated ‘D’ according to the IKDC and excluded from further evaluation. Forty-six patients underwent primary ACLR using the press-fit fixation technique for autologous bone QT graft. These patients were matched in terms of age, gender, accompanying meniscus tear and cartilage injury to 46 patients who underwent standard HT graft with interference screw fixation. Patients were evaluated according to the Lachman test, Pivot-Shift test, IKDC score, Tegner score, Rolimeter measurements, one-leg hop test, thigh circumference and donor side morbidity.

Results

No significant differences in Tegner score (p = 0.9), subjective or objective IKDC score (p = 0.9;p = 0.6), knee stability (Lachman Test p = 0.6; Pivot-Shift Test p = 0.4; Side-to-Side Difference p = 0.4), functioning testing (One-Leg Hop Test p = 0.6; Thigh Circumference p = 0.4) or donor side morbidity (p = 0.4) were observed at the follow up. The Lachman test was negative for 85% of the QT group and 83% of the HT group. The Pivot Shift Test was negative for 80% of the QT group and 85% of the HT group. The mean side-to-side difference was 1.6 ± 0 .2mm in both groups. The one-leg hop test revealed a collateral-side jumping distance of 96.2 ± 8.5% for the QT group and 95.5 ± 8.5% for the HT group. The thigh circumference of the injured leg was 98.3 ± 3.0% on the uninjured side in the QT group and 99.7 ± 3.0% in the HT group. A knee walking test resulted in no discomfort for 90% of the QT group and 85% of the HT group. The graft failure rate was 7.3% in the QT group and 9.8% in the HT group.

Conclusion

QT grafts fixated using the press-fit technique are a reliable alternative for primary ACL surgery.

Sonographic Measurement of the Patellar Tendon Should Predict Autograft Bone Patellar Tendon Bone (BPTB) Size: Comparison of Anatomical and Clinical Findings

The use of BPTB autograft is frequently used in ACL reconstruction, however, the risk of potential failure in patients with an anatomically unfavorable patellar tendon may predispose to reconstruction failure. Anatomical study of the extensor apparatus of the knee can provide knowledge about the best option obtain the graft and perform a better preoperative planning. Musculoskeletal ultrasound is a simple, reproducible, affordable technique that could be valid for patellar tendon evaluation. The objective of this study is to evaluate the reproducibility of the patellar tendon measurements by ultrasound and compare them with anatomical measurements, both in cadaver and patients undergoing ACLR. The study consists of two phases; first anatomical study in cadaver. The ultrasound measurement was performed by determining the length, width and thickness of the patellar tendon, both by ultrasound and anatomical dissection. The second phase is a cohort of 42 patients pending surgical ACLR. Previous ultrasound and intraoperative measurements were obtained. Regarding the anatomical study, statistical analysis did not show any differences comparing the measurements in length (p = ns) and thickness (p = ns) of the patellar tendon, although differences were obtained when comparing the results obtained for the width of the tendon after the ultrasound and anatomical measurement (p < 0.001). Same results were obtained in second phase of the study. The reproducibility of ultrasound measurements of the PT is comparable to intraoperatively measurements (without width measurement). These findings can be useful for preoperative planning in the reconstruction of ACL with BPTB Graft and to assess technical modifications prior to surgery.

Long-term follow-up after anterior cruciate ligament reconstruction using a press-fit quadriceps tendon-patellar bone autograft

Background

The use of a quadriceps tendon-patellar bone (QTPB) autograft provides an alternative procedure in primary reconstruction of the anterior cruciate ligament (ACL). Using the press-fit technique for femoral fixation and knotting over a bone bridge as well as additional spongiosa filling for tibial fixation can completely eliminate the need for fixation implants. The objective of this study was to evaluate the long-term clinical, functional and radiological results of this operating method.

Methods

Sixty-nine patients (27 female-42 male) were included in this study. Fifty-seven patients (83%) received a comprehensive follow-up review after an average period of 7.5 years (range: 7–8.7). All other patients were surveyed by telephone. Six patients (9%) suffered a re-rupture of the ACL graft caused by a new related trauma and were therefore excluded from the statistical analysis.

Results

Of all patients, 98% were satisfied with the operation. Normal or almost normal results were recorded in the subjective IKDC scores form by 88% of the patients. The Lysholm score demonstrated very good and good results in 83% of the patients. Only 1 patient reported minor complaints in the donor area. Seven (12%) patients developed Cyclops syndrome with limited knee extension. This complication was treated arthroscopically within the first year postoperatively. Their results on follow-up were not worse than the results of the patients without Cyclops syndrome.

Regarding the 57 patients who received a comprehensive evaluation, the stability test with the KT-1000 Arthrometer yielded a difference of less than 3 mm in the contralateral comparison for 89% of the operated knees. The pivot-shift test was normal in 79% and almost normal in 21%. In the Single-leg Triple Hop Test, patients achieved an average of 98% of the hopping distance attained with the contralateral leg. The radiological examination revealed a slight deterioration in the Kellgren-Lawrence Score in 2 patients.

Conclusion

The ACL reconstruction using the QTPB autograft performed with the press-fit technique leads to good results in comparison with published results of established procedures for primary ACL surgery using other autografts. Further investigations should involve comparative studies with the objective of providing evidence-based, individually adapted therapy for ACL rupture.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2271-8) contains supplementary material, which is available to authorized users.

Prior Anterior Cruciate Ligament Reconstruction Effects on Future Total Knee Arthroplasty

BACKGROUND

The impact of prior anterior cruciate ligament (ACL) reconstruction on total knee arthroplasty (TKA) has rarely been studied. The objective of this study was to compare intraoperative characteristics in patients who underwent TKA with pre-existing hardware from prior ACL reconstruction with a matched cohort control group.

METHODS

A retrospective study of patients who had undergone primary TKA with pre-existing hardware from prior ACL reconstruction was performed from June 2012 through June 2017. These patients were 2-to-1 matched to the ACL group based on similar patient demographic and provider variables. Outcomes investigated included operative time, estimated blood loss (EBL), and postoperative complications.

RESULTS

One hundred one patients met the inclusion/exclusion criteria. The mean age was 54 ± 9 years, and the mean body mass index was 32.6 ± 6.5 kg/m². The ACL group was divided into 4 subgroups: group 1, no pre-existing hardware removed (22 TKAs); group 2, pre-existing hardware removed from the femur only (8 TKAs); group 3, pre-existing hardware removed from the tibia only (45 TKAs); and group 4, pre-existing hardware removed from both the femur and tibia (26 TKAs). There was no statistical difference in EBL and postoperative complication between the ACL group and controls. Statistical differences were detected between 2 subgroups regarding mean operative time variables: ACL group 3 (74 ± 23 minutes; control: 64 ± 21 minutes, P = .020) and group 4 (79 ± 24 minutes; control: 65 ± 19 minutes, P = .010).

CONCLUSION

Hardware retained, especially on the tibia, from prior ACL reconstruction has a major impact on TKA surgical procedure operative time but not on EBL and/or complications.

Restoring tibiofemoral alignment during ACL reconstruction results in better knee biomechanics

PURPOSE

Anterior cruciate ligament (ACL) reconstruction (ACLR) aims to restore normal knee joint function, stability and biomechanics and in the long term avoid joint degeneration. The purpose of this study is to present the anatomic single bundle (SB) ACLR that emphasizes intraoperative correction of tibiofemoral subluxation that occurs after ACL injury. It was hypothesized that this technique leads to optimal outcomes and better restoration of pathological tibiofemoral joint movement that results from ACL deficiency (ACLD).

METHODS

Thirteen men with unilateral ACLD were prospectively evaluated before and at a mean follow-up of 14.9 (SD = 1.8) months after anatomic SB ACLR with bone patellar tendon bone autograft. The anatomic ACLR replicated the native ACL attachment site anatomy and graft orientation. Emphasis was placed on intraoperative correction of tibiofemoral subluxation by reducing anterior tibial translation (ATT) and internal tibial rotation. Function was measured with IKDC, Lysholm and the Tegner activity scale, ATT was measured with the KT-1000 arthrometer and tibial rotation (TR) kinematics were measured with 3Dmotion analysis during a high-demand pivoting task.

RESULTS

The results showed significantly higher TR of the ACL-deficient knee when compared to the intact knee prior to surgery (12.2° ± 3.7° and 10.7° ± 2.6° respectively, P = 0.014). Postoperatively, the ACLR knee showed significantly lower TR as compared to the ACL-deficient knee (9.6°±3.1°, P = 0.001) but no difference as compared to the control knee (n.s.). All functional scores were significantly improved and ATT was restored within normal values (P < 0.001).

CONCLUSIONS

Intraoperative correction of tibiofemoral subluxation that results after ACL injury is an important step during anatomic SB ACLR. The intraoperative correction of tibiofemoral subluxation along with the replication of native ACL anatomy results in restoration of rotational kinematics of ACLD patients to normal levels that are comparable to the control knee. These results indicate that the reestablishment of tibiofemoral alignment during ACLR may be an important step that facilitates normal knee kinematics postoperatively.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Anterior cruciate ligament reconstruction with quadriceps tendon-patellar bone allograft: matched case control study

Background

Quadriceps tendon-patellar bone (QTPB) autograft is an excellent graft option with good clinical outcome. Use of QTPB autografts have increased because they minimize donor-site morbidity including anterior knee pain, while providing adequate mechanical strength. Although, there were many clinical results about allografts that used in anterior cruciate ligament (ACL) reconstruction, it have never been reported about the clinical outcome of ACL reconstruction with QTPB allograft.

The purpose of this study is to evaluate the clinical outcome of ACL reconstruction with QTPB allograft and to compare with QTPB autograft. We hypothesized that ACL reconstruction with QTPB allograft had good functional outcomes and stability and no significant difference compared to the ACL reconstruction with QTPB autograft.

Methods

From February 2009 to January 2014, 213 cases who received ACL reconstruction with QTPB grafts were included. Forty-five patients who received ACL reconstruction with QTPB allograft were individually matched in age, sex, direction of the injured knee and body mass index (BMI) to a control group of 45 patients who received QTPB autograft. Clinical results were evaluated using International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner scale, Knee injury and Osteoarthritis Outcome Score (KOOS) and ligament laxity. An average follow-up time was 31.2 months.

Results

The functional scores and ligament laxity improved from initial to the last visit in those with ACL reconstruction with QTPB allograft (p < 0.05). No significant statistical difference was found in clinical outcomes and complications including re-rupture between the QTPB allograft and autograft groups (p > 0.05). Laxity using anterior drawer test, Lachman test and KT-2000 showed no significant difference. No significant difference was found between the two groups in quadriceps peak extension torque, except at 60° per second at 6 months.

Conclusion

QTPB allograft achieved good clinical outcome with no difference compared with QTPB autograft. QTPB allograft for ACL reconstruction is promising alternative to selected and compliant patients. Long-term follow-up needs to further evaluate the clinical outcomes and complications including re-rupture rate.

Femoral press-fit fixation versus interference screw fixation in anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft: 20-year follow-up

INTRODUCTION

The aim of this paper is to present our experience with femoral press-fit fixation in anterior cruciate ligament reconstruction using bone-patellar tendon-bone autograft.

METHODS

The patient population was randomly placed in two groups: group A (58 patients), who underwent femoral screw fixation; group B (62 patients), who underwent femoral press-fit fixation.

RESULTS

At last follow-up 9.2% of patients were lost; 28% of patients in group A and 64% of patients in group B had excellent International Knee Documentation Committee score (grade A); 66% of patients in group A and 32% of patients in group B had good International Knee Documentation Committee scores (grade B). The difference was statistically significant (p < 0.05).

CONCLUSIONS

Femoral press-fit fixation of bone- patellar tendon- bone autograft provides stable fixation at low cost, it ensures unlimited bone-to-bone healing and high primary stability, avoiding the disadvantages of hardware and the need for removal in case of revision.

Translation, cultural adaptation and validation of simplified Chinese version of the anterior cruciate ligament return to sport after injury (ACL-RSI) scale

PURPOSE

To translate and cross-culturally adapt the anterior cruciate ligament-return to sport after injury (ACL-RSI) into simplified Chinese [ACL-RSI (Cn)].

METHOD

In this diagnostic study, the translation, cross-culturally adaptation, and validation of the ACL-RSI was performed according to international guidelines. A total of 112 patients with ACL reconstruction participated in this study. All were capable of competitive sports before the injury and completed the Knee Injury and Osteoarthritis Outcome (KOOS), the International Knee Documentation Committee (IKDC), the Tampa Scale of Kinesiophobia (TSK), and the Tegner activity score. Forty-eight patients completed the ACL-RSI (Cn) twice within two weeks. The validity was tested using seven premade hypotheses. Internal consistency, reliability, and measurement error was assessed.

RESULT

At meanly 15.6 months postoperative, 81 (72.3%) patients returned to sport, with 57 (50.9%) to competitive sport and 24 (21.4%) to recreational sport. Thirty-one (27.7%) patients didn't return to any sport, with 19 (17.0%) still had planned to return, and 12 (10.7%) gave up sport. The ACL-RSI (Cn) demonstrated excellent validity with all hypotheses confirmed. The outcome of ACL-RSI (Cn) was strongly correlated the KOOS subscale quality of life (r = 0.66, p<0.001), the TSK (r = -0.678, p<0.001), the Tegner score (r = 0.695, p<0.001). There was statistic difference between cases returned (68.6 ± 10.1) and didn't return to sport (41.3 ± 17.7), p<0.001; between cases returned to competitive (71.1 ± 8.9) and recreational sport (62.9 ± 10.5), (P = 0.002); between cases who planned to return (50.7 ± 14.1) and gave up sport (26.5 ± 11.7), (P<0.001). The internal consistency (Cronbach's α = 0.96) and test-retest reliability [intra-class correlation coefficient (ICC) = 0.90] was excellent. The measurement error, floor and ceiling effect was satisfactory. Administration time was 3.2 minutes, and no item was missed.

CONCLUSIONS

The ACL-RSI (Cn) scale was confirmed as a valid, reliable, and feasible tool for evaluating psychological factors influencing return to sport.

The prevalence of radiographic and MRI-defined patellofemoral osteoarthritis and structural pathology: a systematic review and meta-analysis

BACKGROUND

Patellofemoral osteoarthritis (PF OA) is more prevalent than previously thought and contributes to patient's suffering from knee OA. Synthesis of prevalence data can provide estimates of the burden of PF OA.

OBJECTIVE

This study aims to conduct a systematic review and meta-analysis on the prevalence of PF OA and structural damage based on radiography and MRI studies in different populations.

METHODS

We searched six electronic databases and reference lists of relevant cross-sectional and observational studies reporting the prevalence of PF OA. Two independent reviewers appraised methodological quality. Where possible, data were pooled using the following categories: radiography and MRI studies.

RESULTS

Eighty-five studies that reported the prevalence of patellofemoral OA and structural damage were included in this systematic review. Meta-analysis revealed a high prevalence of radiographic PF OA in knee pain or symptomatic knee OA (43%), radiographic knee OA or at risk of developing OA (48%) and radiographic and symptomatic knee OA (57%) cohorts. The MRI-defined structural PF damage in knee pain or symptomatic population was 32% and 52% based on bone marrow lesion and cartilage defect, respectively.

CONCLUSION

One half of people with knee pain or radiographic OA have patellofemoral involvement. Prevalence of MRI findings was high in symptomatic and asymptomatic population. These pooled data and the variability found can provide evidence for future research addressing risk factors and treatments for PF OA.

TRIAL REGISTRATION NUMBER

PROSPERO systematic review protocol (CRD42016035649).

The effect of anterior cruciate ligament graft rotation on knee biomechanics

PURPOSE

The purpose of this study was to evaluate the effects on knee biomechanics of rotating the distal end of the bone-patellar tendon graft 90° in anatomic single-bundle (SB) anterior cruciate ligament (ACL) reconstruction with a porcine model.

METHODS

Twenty (n = 20) porcine knees were evaluated using a robotic testing system. Two groups and three knee states were compared: (1) intact ACL, (2) deficient ACL and (3) anatomic SB ACL reconstruction with (a) non-rotated graft or (b) rotated graft (anatomic external fibre rotation). Anterior tibial translation (ATT), internal (IR) and external rotation (ER) and the in situ tissue force were measured under an 89-N anterior tibial (AT) load and 4-N m internal and external tibial torques.

RESULTS

A significant difference from the intact ACL was found in ATT at 60° and 90° of knee flexion for rotated and non-rotated graft reconstructions (p < 0.05). There was a significant difference in the in situ force from the intact ACL with AT loading for rotated and non-rotated graft reconstructions at 60° and 90° of knee flexion (p < 0.05). Under IR loading, the in situ force was significantly different from the intact ACL at 30° and 60° of knee flexion for rotated and non-rotated graft reconstructions (p < 0.05). There were no significant differences in ATT, IR, ER and the in situ force between rotated and non-rotated reconstructions.

CONCLUSION

Graft rotation can be used with anatomic SB ACL reconstruction and not have a deleterious effect on knee anterior and rotational biomechanics. This study has clinical relevance in regard to the use of graft rotation to better reproduce the native ACL fibre orientation in ACL reconstruction.

ACL deficiency and varus osteoarthritis: high tibial osteotomy alone or combined with ACL reconstruction?

INTRODUCTION

This study investigates the mid- to long-term clinical and radiological outcome in patients with symptomatic varus osteoarthritis (OA) and deficiency of the anterior cruciate ligament (ACL) and analyzes whether there are differences between isolated high tibial osteotomy (HTO) or combined single-stage HTO and ACL reconstruction (ACLR).

METHODS

26 patients who underwent HTO alone (group 1) and 26 patients who underwent single-stage HTO and ACLR (group 2) because of varus OA and ACL deficiency were examined at a mean of 5.8 years (SD 3.6 years) post-operatively. Assessment at follow-up (FU) was performed using a questionnaire including clinical scores (Lysholm, IKDC) and the KT-2000 arthrometer to examine anterior knee stability. Radiographic knee alignment and signs of OA according to the classification of Kellgren and Lawrence (KL) were assessed pre-operatively and at FU.

RESULTS

Eighty-one percent of all patients reported an improvement of pain and 79% an improvement of instability without significant group difference. Significant worse results were observed in group 1 for the Lysholm score (group 1: 69.4, SD 15.7; group 2: 78.3, SD 16.4; p = 0.020) and the IKDC score (group 1: 64.8, SD 13.0; group 2: 74.0, SD 15.6; p = 0.006). No group difference was found for the KT-2000 examination. A significant post-operative increase of radiographic OA could be seen in both groups without significant group difference (KL pre-operative: 2.3, SD 0.63; KL FU: 2.8, SD 0.74; p < 0.001). The radiographic leg alignment at FU showed a significant lower valgus alignment in group 1 (group 1: 0.4 degree, SD 3.3 degree; group 2: 2.1 degree, SD 2.1 degree; p = 0.039). The rate of post-operative complications was low with 4%, and no significant group differences were found.

CONCLUSIONS

This study shows that HTO alone can improve pain and even subjective knee stability. Additional ACLR was in the mid term not associated with a higher increase of OA or a higher rate of post-operative complications in our study collective.

Enhancement of tendon-bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction.

Biomechanical comparison of two surgical techniques for press-fit reconstruction of the posterolateral complex of the knee

BACKGROUND

To date, various surgical techniques to treat posterolateral knee instability have been described. Recent studies recommended an anatomical and isometric reconstruction of the posterolateral corner addressing the key structures, such as lateral collateral ligament (LCL), popliteus tendon (POP) and popliteofibular ligament (PFL). Two clinical established autologous respective local reconstruction methods of the posterolateral complex were tested for knot-bone cylinder press-fit fixation to assess efficacy of each reconstruction technique in comparison to the intact knee.

NULL HYPOTHESIS

The knot-bone cylinder press-fit fixation for both anatomic and isometric reconstruction techniques of the posterolateral complex shows equal biomechanical stability as the intact posterolateral knee structures.

STUDY DESIGN

This was a controlled laboratory study.

METHODS

Two surgical techniques (Larson: fibula-based semitendinosus autograft for LCL and PFL reconstruction/Kawano: biceps femoris and iliotibial tract autograft for LCL, PFL and POP reconstruction) with press-fit fixation were used for restoration of posterolateral knee stability. Seven cadaveric knees (66 ± 3.4 years) were tested under three conditions: intact knee, sectioned state and reconstructed knee for each surgical technique. Biomechanical stress tests were performed for every state at 30° and 90° knee flexion for anterior-posterior translation (60 N), internal-external and varus-valgus rotation (5 Nm) at 0°, 30° and 90° using a kinemator (Kuka robot).

RESULTS

At 30° and 90° knee flexion, no significant differences between the four knee states were registered for anterior-posterior translation loading. Internal-external and varus-valgus rotational loading showed significantly higher instability for the sectioned state than for the intact or reconstructed posterolateral structures (p < 0.05). There were no significant differences between the intact and reconstructed knee states for internal-external rotation, varus-valgus rotation and anterior-posterior translation at any flexion angles (p > 0.05). Comparing both reconstruction techniques, significant higher varus-/valgus stability was registered for the fibula-based Larson technique at 90° knee flexion (p < 0.05).

CONCLUSIONS

Both PLC reconstructions showed equal biomechanical stability as the intact posterolateral knee structures when using knot-bone cylinder press-fit fixation. We registered restoration of the rotational and varus-valgus stability with both surgical techniques. The anterior-posterior translational stability was not influenced significantly. The Larson technique showed significant higher varus/valgus stability in 90° flexion. The latter is easier to perform and takes half the preparation time, but needs grafting of the semitendinosus tendon. The Kawano reconstruction technique is an interesting alternative in cases of missing autografts.

A novel implant-free tibial pull-press-fixation for ACL reconstruction

INTRODUCTION

Extracortical fixation techniques in anterior cruciate ligament reconstruction bear the risk of tunnel enlargement, while close-to-aperture fixations often show lower failure loads. The purpose for this study was to investigate the biomechanical benefits of a novel implant-free combination of an extra-cortical and close-to-aperture fixation.

MATERIALS AND METHODS

Quadrupled human cadaveric semitendinosus tendons were fixed to 30 porcine tibiae with either a cannulated interference screw (I), an implant-free post-fixation (S), or a novel pull-press fixation (P). Specimens were cyclically loaded 20 times between 20 and 60 N followed by 500 cycles with 60-200 N, followed by a load-to-failure test with 1 mm/s.

RESULTS

The mean elongation of the tendons in the P-group during the 500 cycles between 60 and 200 N was significantly lower (5.69 ± 2.16 mm) compared to 9.20 ± 3.21 mm in S-group and 9.37 ± 3.1 mm in the I-group (p < 0.05). The mean maximum load-to-failure was significantly higher in the P-group (728.2 ± 76.4 N) compared to 476.4 ± 68.8 N in the S-group and 625.9 ± 82.5 N in the I-group (p < 0.05). Stiffness of the constructs in the P-group was significantly higher (121.7 ± 44.9 N/mm) compared to 46.2 ± 17.7 N/mm in the S- and 72.8 ± 29.8 N/mm in the I-group (p < 0.03).

CONCLUSIONS

This study indicates superior biomechanical properties of a novel implant-free tibial pull-press fixation to conventional implant-free and close-to-aperture interference screw fixations in terms of cyclic elongation and maximum load-to-failure.

LEVEL OF EVIDENCE

Not applicable, basic science study.

Complex function of the knee joint: the current understanding of the knee

Since the early years of orthopaedics, it is a well-known fact that anatomy follows function. During the evolution of mankind, the knee has been optimally adapted to the forces and loads acting at and through the knee joint. However, anatomy of the knee joint is variable and the only constant is its complex function. In contrast to the time of open surgery, nowadays the majority of reconstructive knee surgery is done arthroscopically. Keyhole surgery is less invasive, but on the backside, the knee surgeon lacks daily visualisation of the complex open anatomy. As open anatomical knowledge is less present in our daily practice, it is even more important to highlight this complex anatomy and function of the knee. It is the purpose of this review to perform a systematic review of knee anatomy, highlight the complex function of the knee joint and present an overview about recent and current knowledge about knee function. Level of evidence Systematic review, Level IV.

Three-dimensional kinematic analysis of ankle, knee, hip, and pelvic rotation during gait in patients after anterior cruciate ligament reconstruction - early results

Background

The goal of this study was to biomechanically assess tibial rotation in the knee joint simultaneous changes in rotation of large joints of the lower limbs and pelvis during gait in patients during early postoperative stages following anterior cruciate ligament (ACLR) reconstruction.

We hypothesized that tibial rotation is associated with changes in rotation of the large joints of the lower limbs and the pelvis during gait in patients after ACLR reconstruction.

Methods

The patients were divided into two groups. The ACLR group (n = 32 males) underwent primary ACLR in one leg and postoperative physiotherapy. The control group (n = 30 males) had no knee injuries. After clinical assessment in both groups, the values of kinematic parameters of foot, tibial, femoral, and pelvic rotation were measured during gait on a flat surface using the three-dimensional BTS Smart System. In the ACLR group, measurements were taken during the 4th, 9th, and 14th weeks of postoperative physiotherapy. The results of the ACLR group were compared with those of the control group.

Results

During gait, between the 9th and 14th weeks following ACLR, there are normal values of foot, tibia, and pelvic rotation in the operated legs compared with results obtained from un-operated legs and the control group.

Discussion

Analysis of rotations occurring only in knee joints does not reflect all of the multiarticular disorders of gait kinematics. The study also suggests that analyzing tibial rotation in the knee joint with simultaneous changes in rotation in large joints of the lower limbs provides better opportunities than singular analysis of rotation in the knee joint for the assessment of disorders in gait kinematics.

Conclusions

In gait, at the maximal extension of the knee during preparation for the stance phase, external hip rotation patterns have not been fully restored 14 weeks after ACLR.

Press-fit fixation using autologous bone in the tibial canal causes less enlargement of bone tunnel diameter in ACL reconstruction--a CT scan analysis three months postoperatively

Background

Bone tunnel enlargement is a phenomenon present in all anterior cruciate ligament (ACL)- reconstruction techniques. It was hypothesized that press-fit fixation using a free autograft bone plug reduces the overall tunnel size in the tibial tunnel.

Methods

In a prospective cohort study twelve patients who underwent primary ACL reconstruction using an autologous quadriceps tendon graft and adding a free bone block for press-fit fixation (PF) in the tibial tunnel were matched to twelve patients who underwent ACL reconstruction with a hamstring graft and interference screw fixation (IF). The diameters of the bone tunnels were analysed by a multiplanar reconstruction technique (MPR) in a CT scan three months postoperatively. Manual and instrumental laxity (Lachman test, Pivot-shift test, Rolimeter) and functional outcome scores (International Knee Documentation Committee sore, Tegner activity level) were measured after one year follow up.

Results

In the PF group the mean bone tunnel diameter at the level of the joint entrance was not significantly enlarged. One and two centimeter distal to the bone tunnel diameter was reduced by 15 % (p = .001). In the IF group the bone tunnel at the level of the joint entrance was enlarged by 14 % (p = .001). One and two centimeter distal to the joint line the IF group showed a widening of the bone tunnel by 21 % (p < .001) One and two centimeter below the joint line the bone tunnel was smaller in the PF group when compared to the IF group (p < .001). No significant difference for laxity test and functional outcome scores could be shown.

Conclusion

This study demonstrates that press-fit fixation with free autologous bone plugs in the tibial tunnel results in significantly smaller diameter of the tibial tunnel compared to interference screw fixation.

Over-the-Top Anterior Cruciate Ligament Reconstruction Using Single- or Double-Strand Hamstrings Autograft

The purpose of this study is to (1) report the long-term clinical and radiographic outcomes of a nonanatomical anterior cruciate ligament (ACL) reconstruction using an over-the-top (OTT) femoral route and (2) compare single-strand (1SHG) and double-strand (2SHG) hamstrings graft reconstruction. Fifty-one consecutive patients (mean age, 29.2±3.8 years) underwent nonanatomical ACL reconstruction using OTT femoral passage. Twenty patients underwent 1SHG reconstruction and 31 underwent 2SHG reconstruction. International Knee Documentation Committee (IKDC) score, Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner score, and KT-1000 (Medmetric Corporation, San Diego, California) evaluation were recorded at a mean follow-up of 12.1±1.6 years. At final follow-up, radiographic evaluation was performed according to the IKDC grading system. Mean IKDC subjective score at follow-up was 76.6±21.9 in the 1SHG group and 88.9±10.0 in the 2SHG (P=.009). Average KOOS was 82.6±18.7 in the 1SHG group and 92.4±9.2 in the 2SHG group (P=.016). Objective IKDC evaluation showed a higher percentage of normal knees in the 2SHG group (P=.018). Pivot shift testing revealed a significantly higher number of normal knees in the 2SHG group (P=.001). Radiographs showed fewer degenerative changes in the 2SHG group at final follow-up in the medial (P=.01) and lateral (P=.037) compartments. Nonanatomical ACL reconstruction using the OTT technique provided satisfactory results in terms of control of both static and dynamic instability at long-term follow-up, thus preventing degenerative joint disease. The 2SHG group showed better subjective and functional outcomes with fewer degenerative changes compared with the 1SHG group at long-term follow-up.

Tibiofemoral Osteoarthritis After Surgical or Nonsurgical Treatment of Anterior Cruciate Ligament Rupture: A Systematic Review

OBJECTIVE

  To determine if surgical or nonsurgical treatment of anterior cruciate ligament rupture affects the prevalence of posttraumatic tibiofemoral osteoarthritis (OA).

DATA SOURCES

  Studies published between 1983 and April 2012 were identified via EBSCOhost and OVID. Reference lists were then screened in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

STUDY SELECTION

  Studies were included if (a) treatment outcomes focused on a direct comparison of surgical versus nonsurgical treatment of anterior cruciate ligament rupture, (b) the prevalence of tibiofemoral OA was reported, and (c) they were written in English. Studies were excluded if (a) the included patients were treated with cast immobilization after surgery, (b) the mean follow-up was less than 10 years, or (c) the patients underwent anterior cruciate ligament revision surgery.

DATA EXTRACTION

  Two independent investigators reviewed the included articles using the Newcastle-Ottawa Scale. Frequency of OA, surgical procedure, nonsurgical treatments, and participant characteristics were extracted and summarized. We calculated prevalence (%) and 95% confidence intervals for treatment groups for each individual study and overall. We developed 2 × 2 contingency tables to assess the association between treatment groups (exposed had surgery, referent was nonsurgical treatment) and the prevalence of OA.

DATA SYNTHESIS

  Four retrospective studies were identified (140 surgical patients, 240 nonsurgical patients). The mean Newcastle-Ottawa Scale score was 5 (range = 4-6 [of 10] points). Average length of follow-up was 11.8 years (range = 10-14 years). The prevalence of OA for surgically treated patients ranged from 32.6% to 51.2% (overall = 41.4%, 95% confidence interval = 35.0%, 48.1%) and for nonsurgical patients ranged from 24.5% to 42.3% (overall = 30.9%, 95% confidence interval = 24.4%, 38.3%).

CONCLUSIONS

  Although OA prevalence was higher in the surgical treatment group at a mean follow-up of 11.8 years, no definitive evidence supports surgical or nonsurgical treatment after anterior cruciate ligament injury to prevent posttraumatic OA. Current studies have been limited by small sample sizes, low methodologic quality, and a lack of data regarding confounding factors.

Osteoarthritis prevalence following anterior cruciate ligament reconstruction: a systematic review and numbers-needed-to-treat analysis

OBJECTIVE

To determine the prophylactic capability of anterior cruciate ligament (ACL) reconstruction in decreasing the risk of knee osteoarthritis (OA) when compared with ACL-deficient patients, as well as the effect of a concomitant meniscectomy. We also sought to examine the influence of study design, publication date, and graft type as well as the magnitude of change in physical activity from preinjury Tegner scores in both cohorts.

DATA SOURCES

We searched Web of Science and PubMed databases from 1960 through 2012 with the search terms osteoarthritis, meniscectomy, anterior cruciate ligament, anterior cruciate ligament reconstruction, and anterior cruciate ligament deficient.

STUDY SELECTION

Articles that reported the prevalence of tibiofemoral or patellofemoral OA based on radiographic assessment were included. We calculated numbers needed to treat and relative risk reduction with associated 95% confidence intervals for 3 groups (1) patients with meniscal and ACL injury, (2) patients with isolated ACL injury, and (3) total patients (groups 1 and 2).

DATA EXTRACTION

A total of 38 studies met the criteria. Of these, 27 assessed the presence of tibiofemoral osteoarthritis in patients treated with anterior cruciate ligament reconstruction.

DATA SYNTHESIS

Overall, ACL reconstruction (ACL-R) yielded a numbers needed to treat to harm of 16 with a relative risk increase of 16%. Anterior cruciate ligament reconstruction along with meniscectomy yielded a numbers needed to treat to benefit of 15 and relative risk reduction of 11%. Isolated ACL-R showed a numbers needed to treat to harm of 8 and relative risk increase of 43%. Activity levels were decreased in both ACL-R (d = -0.90; 95% confidence interval = 0.77, 1.13) and ACL-deficient (d = -1.13; 95% confidence interval = 0.96, 1.29) patients after injury.

CONCLUSIONS

The current literature does not provide substantial evidence to suggest that ACL-R is an adequate intervention to prevent knee osteoarthritis. With regard to osteoarthritis prevalence, the only patients benefiting from ACL-R were those undergoing concomitant meniscectomy with reconstruction.

Incidence and trends of anterior cruciate ligament reconstruction in the United States

BACKGROUND

Anterior cruciate ligament (ACL) injury is among the most commonly studied injuries in orthopaedics. The previously reported incidence of ACL injury in the United States has varied considerably and is often based on expert opinion or single insurance databases.

PURPOSE

To determine the incidence of ACL reconstruction (ACLR) in the United States; to identify changes in this incidence between 1994 and 2006; to identify changes in the demographics of ACLR over the same time period with respect to location (inpatient vs outpatient), sex, and age; and to determine the most frequent concomitant procedures performed at the time of ACLR.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

International Classification of Diseases, 9th Revision (ICD-9) codes 844.2 and 717.83 were used to search the National Hospital Discharge Survey (NHDS) and the National Survey of Ambulatory Surgery (NSAS) for the diagnosis of ACL tear, and the procedure code 81.45 was used to search for ACLR. The incidence of ACLR in 1994 and 2006 was determined by use of US Census Data, and the results were then stratified based on patient age, sex, facility, concomitant diagnoses, and concomitant procedures.

RESULTS

The incidence of ACLR in the United States rose from 86,687 (95% CI, 51,844-121,530; 32.9 per 100,000 person-years) in 1994 to 129,836 (95% CI, 94,993-164,679; 43.5 per 100,000 person-years) in 2006 (P = .015). The number of ACLRs increased in patients younger than 20 years and those who were 40 years or older over this 12-year period. The incidence of ACLR in females significantly increased from 10.36 to 18.06 per 100,000 person-years between 1994 and 2006 (P = .0003), while that in males rose at a slower rate, with an incidence of 22.58 per 100,000 person-years in 1994 and 25.42 per 100,000 person-years in 2006. In 2006, 95% of ACLRs were performed in an outpatient setting, while in 1994 only 43% of ACLRs were performed in an outpatient setting. The most common concomitant procedures were partial meniscectomy and chondroplasty.

CONCLUSION

The incidence of ACLR increased between 1994 and 2006, particularly in females as well as those younger than 20 years and those 40 years or older. Research efforts as well as cost-saving measures may be best served by targeting prevention and outcomes measures in these groups. Surgeons should be aware that concomitant injury is common.

Imaging following acute knee trauma

Joint injury has been recognized as a potent risk factor for the onset of osteoarthritis. The vast majority of studies using imaging technology for longitudinal assessment of patients following joint injury have focused on the injured knee joint, specifically in patients with anterior cruciate ligament injury and meniscus tears where a high risk for rapid onset of post-traumatic osteoarthritis is well known. Although there are many imaging modalities under constant development, magnetic resonance (MR) imaging is the most important instrument for longitudinal monitoring after joint injury. MR imaging is sensitive for detecting early cartilage degeneration and can evaluate other joint structures including the menisci, bone marrow, tendons, and ligaments which can be sources of pain following acute injury. In this review, focusing on imaging following acute knee trauma, several studies were identified with promising short-term results of osseous and soft tissue changes after joint injury. However, studies connecting these promising short-term results to the development of osteoarthritis were limited which is likely due to the long follow-up periods needed to document the radiographic and clinical onset of the disease. Thus, it is recommended that additional high quality longitudinal studies with extended follow-up periods be performed to further investigate the long-term consequences of the early osseous and soft tissue changes identified on MR imaging after acute knee trauma.

Arthroscopic BPTB graft reconstruction in ACL ruptures: 15-year results and survival

PURPOSE

The aim of this study is to investigate the 15-year results and survival of arthroscopic ACL reconstruction using the central-third patellar bone-tendon-bone (BPTB) autograft.

METHODS

ACL BPTB reconstruction was performed in 250 consecutive patients. Of these patients, 88% returned for a follow-up examination at 15 years after reconstruction. Therefore, 220 patients were studied. Mean time from injury to intervention was 3.4months (range 2 to 16). The parameters for assessment of results were subjective satisfaction, clinical examination (pivot-shift test, Lachman test with KT-1000), recovery of pre-injury activity level, and long-leg standing radiographs. We also evaluated the presence of meniscal and/or chondral injuries during the procedure. Failure rates were also evaluated. We defined a failure as severe instability not compatible with the activities of daily living (ADL) due to graft rupture.

RESULTS

8.2% of patients required a revision procedure because of graft rupture. In subjective terms, 98.1% of patients said that they were satisfied with the surgical outcomes after 15 years. Pivot shift test was normal in 93.5% at 15 years. Lachman test (KT-1000) was normal in 95.4% at 15 years. Fifteen years after surgery, 90% of patients recovered their pre-injury activity level. In 25.4% of patients symptomatic osteoarthritic changes in the knee were found at 15 years.

CONCLUSIONS

The survival prevalence of arthroscopic ACL reconstruction using the central-third patellar bone-tendon-bone (BPTB) autograft at 15 years was 94.8%. Fifteen years after surgery, 90% of patients recovered their pre-injury activity level. In 25.4% of patients symptomatic osteoarthritic changes in the knee were found at 15 years.

LEVEL OF EVIDENCE

Level IV.

Anterior cruciate ligament injury and radiologic progression of knee osteoarthritis: a systematic review and meta-analysis

BACKGROUND

Knee osteoarthritis after anterior cruciate ligament (ACL) injury has previously been reported. However, there has been no meta-analysis reporting the development and progression of osteoarthritis.

PURPOSE

We present the first meta-analysis reporting on the development and progression of osteoarthritis after ACL injury at a minimum mean follow-up of 10 years, using a single and widely accepted radiologic classification, the Kellgren & Lawrence classification.

STUDY DESIGN

Meta-analysis.

METHOD

Articles were included for systematic review if they reported radiologic findings of ACL-injured knees and controls using the Kellgren & Lawrence classification at a minimum mean follow-up period of 10 years. Appropriate studies were then included for meta-analysis.

RESULTS

Nine studies were included for systematic review, of which 6 studies were further included for meta-analysis. One hundred twenty-one of 596 (20.3%) ACL-injured knees had moderate or severe radiologic changes (Kellgren & Lawrence grade III or IV) compared with 23 of 465 (4.9%) uninjured ACL-intact contralateral knees. After ACL injury, irrespective of whether the patients were treated operatively or nonoperatively, the relative risk (RR) of developing even minimal osteoarthritis was 3.89 (P < .00001), while the RR of developing moderate to severe osteoarthritis (grade III and IV) was 3.84 (P < .0004). Nonoperatively treated ACL-injured knees had significantly higher RR (RR, 4.98; P < .00001) of developing any grade of osteoarthritis compared with those treated with reconstructive surgery (RR, 3.62; P < .00001). Investigation of progression to moderate or severe osteoarthritis (grade III or IV only) after 10 years showed that ACL-reconstructed knees had a significantly higher RR (RR, 4.71; P < .00001) compared with nonoperative management (RR, 2.41; P = .54). It was not possible to stratify for return to sports among the patients undergoing ACL reconstruction.

CONCLUSION

Results support the proposition that ACL injury predisposes knees to osteoarthritis, while ACL reconstruction surgery has a role in reducing the risk of developing degenerative changes at 10 years. However, returning to sports activities after ligament reconstruction may exacerbate the development of arthritis.

ACL reconstruction using bone-patella tendon-bone autograft: press-fit technique vs. interference screw fixation

PURPOSE

The gold standard in ACL reconstructions has been the bone-patellar tendon-bone autograft fixed with interference screws. This prospective, randomized clinical trial aimed to compare two methods of fixation for BPTB grafts: press-fit fixation vs. interference screw, over a 12-month follow-up interval.

METHODS

158 patients with an average age of 29.8 years, between 2011 and 2012, were treated for torn ACL. 82 patients underwent reconstruction with BPTB autograft with a press fit fixation technique, and in 76 cases an interference screw was used. At the time of final follow-up, 71 patients in press-fit group and 65 patients in interference screw group were evaluated in terms of return to pre-injury activity level, pain, knee stability, range of motion, IKDC score and complications.

RESULTS

At 12-month follow-up, 59 (83 %) and 55 (85 %) in press-fit and screw group, respectively had good-to-excellent IKDC score (p > 0.05). The mean laxity assessed using a KT-1000 arthrometer improved to 2.7 and 2.5 mm in press-fit and screw group, respectively. Regarding Lachman and pivot shift test, there was a statistically significant improvement in the integrity of the ACL in both the groups, but no significant differences was noted between groups. There were no significant differences in terms of femur circumference difference, effusion, knee range of motion, pain and complications.

CONCLUSIONS

The press-fit technique is an efficient procedure. Its outcome was comparable with the interference screw group. Furthermore it has unlimited bone-to-bone healing, no need for removal of hardware, ease for revision and cost effectiveness.

Long-term follow-up of ACL reconstruction with hamstring autograft

PURPOSE

To investigate the differences in the incidence and severity of knee osteoarthritis (OA), joint space narrowing, knee laxity, and knee flexion and extension strength between an anterior cruciate ligament (ACL)-reconstructed knee and the contralateral non-reconstructed limb.

METHODS

Retrospective case series of patients from a single surgeon that had an ACL reconstruction with a semitendinosus/gracilis autograft more than 12 years ago. Outcome measures included radiographic analysis, International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC), KT-1000, Tegner Activity Level Scale, Lysholm Knee Score, ACL quality of life score (ACL-QOL) and knee flexor/extensor strength.

RESULTS

Seventy-four patients consented and sixty-eight (43 male, 25 female) were included for analysis. Average age (SD) at the time of surgery was 31.2 (±9.1) years. At follow-up of 14.6 (1.9) years, 9% had re-ruptured their ACL, whereas 5% ruptured the contralateral ACL. Reconstructed knees had a greater incidence and severity of OA (P < 0.01). Medial meniscus surgery was a strong predictor of OA. Seventy-five per cent scored a normal or nearly normal knee on the IKDC. The mean Lysholm score was 75.8% and Tegner Activity Level Scale scores decreased (P < 0.001) from the time of surgery. Knee extension strength was greater in the contralateral knee at speeds of 60°/s (P = 0.014) and 150°/s (P = 0.012).

CONCLUSIONS

Reconstructed knees have a greater incidence and severity of OA than non-reconstructed knees, which suggests degenerative changes are secondary to ACL rupture. Medial meniscus surgery is a strong predictor of OA. Despite this, 75% of patients reported good outcomes.

The PCL index is correlated with the control of rotational kinematics that is achieved after anatomic anterior cruciate ligament reconstruction

BACKGROUND

The posterior cruciate ligament (PCL) index quantifies the curvature of the PCL seen on magnetic resonance imaging (MRI) that is caused by a change in tibiofemoral alignment in the anterior cruciate ligament (ACL)-deficient knee. It has been proposed that the PCL index may be useful in assessing the success of ACL reconstruction (ACLR). Hypothesis/

PURPOSE

The purpose of this study was to test if the PCL index is predictive of in vivo rotational kinematics and joint laxity measures in knees of patients after single-bundle ACLR. The hypothesis was that the PCL index is predictive of rotational knee kinematics and objective laxity scores.

STUDY DESIGN

Controlled laboratory study.

METHODS

At a mean of 18.1 months postoperatively, the PCL index was defined on MRI in 16 patients prospectively followed up after anatomic single-bundle ACLR and in 16 matched controls. The patients were evaluated with 3-dimensional motion analysis during (1) descending and pivoting as well as (2) landing and pivoting tasks. The side-to-side difference in tibial rotation range of motion between the reconstructed knee and the contralateral intact knee was calculated. The side-to-side difference in anterior tibial translation was measured with a KT-1000 arthrometer. Linear regression models were used with the PCL index as a predictor of the side-to-side difference in tibial rotation for each task and the side-to-side difference in anterior tibial translation.

RESULTS

The PCL index of the reconstructed knees was significantly lower compared with that of the control knees (P < .001). The index was predictive of the side-to-side difference in tibial rotation during both tasks (R (2) = 0.472 and 0.477, P = .003), with a lower index being indicative of increased rotational laxity. It was not predictive of anterior tibial translation (at 134 N: R (2) = 0.13, P = .17; at maximum force: R (2) = 0.009, P = .726).

CONCLUSION

The PCL index after anatomic single-bundle ACLR using a bone-patellar tendon-bone graft is predictive of rotational kinematics during in vivo dynamic pivoting activities. The results show that the PCL index is correlated with the postoperative ability to control rotational kinematics of the knee joint.

CLINICAL RELEVANCE

This study provides evidence regarding the interplay between restoration of the native ACL's anatomy and the PCL's appearance and suggests that the effective restoration of tibiofemoral alignment after ACLR that is reflected in the PCL index translates into better functional outcomes as measured by tibial rotation during pivoting activities.