Anterior cruciate ligament rupture and osteoarthritis progression

Management after acute rupture of the anterior cruciate ligament (ACL). Part 1: ACL reconstruction has a protective effect on secondary meniscus and cartilage lesions

PURPOSE

The aim of this consensus project was to validate which endogenous and exogenous factors contribute to the development of post-traumatic osteoarthritis and to what extent ACL (anterior cruciate ligament) reconstruction can prevent secondary damage to the knee joint. Based on these findings, an algorithm for the management after ACL rupture should be established.

METHODS

The consensus project was initiated by the Ligament Injuries Committee of the German Knee Society (Deutsche Kniegesellschaft, DKG). A modified Delphi process was used to answer scientific questions. This process was based on key topic complexes previously formed during an initial face-to-face meeting of the steering group with the expert group. For each key topic, a comprehensive review of available literature was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Consensus was defined a-priori as eighty percent agreement.

RESULTS

Of the 17 final statements, 15 achieved consensus, and 2 have not reached consensus. Results of the consensus were summarized in an algorithm for the management after ACL rupture (infographic/Fig. 2).

CONCLUSION

This consensus process has shown that the development of post-traumatic osteoarthritis is a complex multifactorial process. Exogenous (primary and secondary meniscus lesions) and endogenous factors (varus deformity) play a decisive role. Due to the complex interplay of these factors, an ACL reconstruction cannot always halt post-traumatic osteoarthritis of the knee. However, there is evidence that ACL reconstruction can prevent secondary joint damage such as meniscus lesions and that the success of meniscus repair is higher with simultaneous ACL reconstruction. Therefore, we recommend ACL reconstruction in case of a combined injury of the ACL and a meniscus lesion which is suitable for repair.

LEVEL OF EVIDENCE

Level V.

Injectable recombinant block polymer gel for sustained delivery of therapeutic protein in post traumatic osteoarthritis

Protein-based biomaterials offer several advantages over synthetic materials, owing to their unique stimuli-responsive properties, biocompatibility and modular nature. Here, we demonstrate that E5C, a recombinant protein block polymer, consisting of five repeats of elastin like polypeptide (E) and a coiled-coil domain of cartilage oligomeric matrix protein (C), is capable of forming a porous networked gel at physiological temperature, making it an excellent candidate for injectable biomaterials. Combination of E5C with Atsttrin, a chondroprotective engineered derivative of anti-inflammatory growth factor progranulin, provides a unique biochemical and biomechanical environment to protect against post-traumatic osteoarthritis (PTOA) onset and progression. E5C gel was demonstrated to provide prolonged release of Atsttrin and inhibit chondrocyte catabolism while facilitating anabolic signaling in vitro. We also provide in vivo evidence that prophylactic and therapeutic application of Atsttrin-loaded E5C gels protected against PTOA onset and progression in a rabbit anterior cruciate ligament transection model. Collectively, we have developed a unique protein-based gel capable of minimally invasive, sustained delivery of prospective therapeutics, particularly the progranulin-derivative Atsttrin, for therapeutic application in OA.

Six-month post-surgical elevations in cartilage T1rho relaxation times are associated with functional performance 2 years after ACL reconstruction

The current study looks to: (i) investigate postural stability following anterior cruciate ligament (ACL) reconstruction, as assessed by Y-Balance Test, by comparing single-leg balance of the injured limb against those of controls and the uninjured limb; (ii) analyze the relationship between postural stability symmetry with localized cartilage matrix changes and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Bilateral knee MRI of 36 patients who underwent ACL reconstruction were performed before surgery, 6 months, 1 year, and 2 years, postoperatively. Postural stability was evaluated based on Y-Balance Test at 1 and 2 years. ACL patients were also split into three groups based on postural stability symmetry at 2 years and symmetry thresholds associated with elevated risks of lower extremity injury. Voxel-based relaxometry employing analysis of covariance was used to analyze localized differences in cartilage composition at all time-points (using quantitative magnetic resonance [MR] T1ρ and T2 mapping) between the three groups. The ACL patients displayed no significant deficits in postural stability. Compared with symmetric patients, those with asymmetric postural stability at 2 years had significantly prolonged cartilage T1ρ-indicating deterioration of the cartilage matrix-specifically in the injured knee's medial tibia as early as 6-month post-reconstruction. Prolonged T1ρ in asymmetric patients persisted up to 2 years, where the group also reported worse KOOS. Our results demonstrate an association between early stages of cartilage matrix deterioration and postural stability symmetry that may manifest in elevated lower extremity injury risk and worse patient-reported outcomes. Quantitative MR, in combination with local analysis performed with voxel-based relaxometry, is a tool to further study this relationship. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1132-1140, 2020.

Posterior tibial slope modification in osteoarthritis knees with different ACL conditions: Cadaveric study of fixed-bearing UKA

Unicompartmental knee arthroplasty (UKA) in anterior cruciate ligament deficiency (ACLD) has been debated for decades after the development of highly cross-linked polyethylene. This study aims to evaluate the effect of posterior tibial slope on restoring adequate knee stability and flexion after UKA in patients with ACLD. A total of 15 fresh cadaveric knees were divided into three groups: intact ACL, partial ACLD, and complete ACLD. Fixed-bearing UKAs including 3-D-printed tibial inserts with the slopes ranging from 3° to 12° were performed using computer-assisted navigation. Blinded evaluation of knee motion and anterior knee translation with knees flexed 20° and 90° was conducted using KT-arthrometry and stress radiography. A 1° slope increase translated the knees anteriorly by 0.85 mm and 0.76 mm in 20° and 90° of knee flexion for a complete ACLD ( R = 0.7 and 0.8, respectively, p < 0.001) compared to 0.5-0.6 mm for the normal and partial ACLD groups, respectively. Setting a slope of 5-8° of UKA for an intact ACL maintained both the stability and the motion of native knees. No significant changes of knee translation and flexion ability were observed after leveling the slopes at 5-7° and 5-6° for partial and complete ACLD, respectively ( p > 0.05 for all comparisons). In conclusion, UKA in complete ACLD knees is challenging since 1° of slope change nearly doubles the degree of knee translation compared to ACL-intact knees. The optimum posterior tibial slopes for fixed-bearing UKA patients with partial and complete ACLD are 5-7° and 5-6°, respectively.

The protective effect of anterior cruciate ligament reconstruction on articular cartilage: a systematic review of animal studies

OBJECTIVE

It is unclear if anterior cruciate ligament (ACL) reconstruction can prevent the onset of degenerative changes in the knee. Previous studies were inconclusive on this subject. The aim of this study was to systematically review all studies on the effect of ACL reconstruction on articular cartilage in animals.

DESIGN

Pubmed and Embase were searched to identify all original articles concerning the effect of ACL reconstruction on articular cartilage compared with both its positive (ACL transection) and negative (sham and/or non-operated) control in animals. Subsequently a Risk of bias and meta analysis was conducted based on five outcomes (gross macroscopic assessment, medical imaging, histological histochemical grading, histomophometrics and biomechanical characterization) related to articular cartilage.

RESULTS

From the 19 included studies, 29 independent comparisons could be identified which underwent ACL reconstruction with an average timing of data collection of 23 weeks (range 1-104 weeks). Due to limited data availability meta-analysis could only be conducted for gross macroscopic damage. ACL reconstruction caused significant gross macroscopic damage compared with intact controls (SMD 2.0 [0.88; 3.13]). These findings were supported by individual studies reporting on histomorphometrics, histology and imaging. No significant gross macroscopic damage was found when ACL reconstruction was compared with ACL transection (SMD -0.64 [-1.85; 0.57]).

CONCLUSION

This systematic review with an average follow up of included studies of 23 weeks (range 1-104 weeks) demonstrates that, in animals, ACL reconstruction does not protect articular cartilage from degenerative changes. The consistency of the direction of effect, provides some reassurance that the direction of effect in humans might be the same.

Does the Lever Sign Test Have Added Value for Diagnosing Anterior Cruciate Ligament Ruptures?

Background:

Diagnosing an anterior cruciate ligament (ACL) rupture based on a physical examination remains a challenge for both surgeons and physical therapists. The lever sign test was developed to overcome the practical limitations of other tests and to optimize diagnosis. An evaluation of the measurement properties of the lever sign test is needed to make adequate interpretations in practice.

Purpose:

To evaluate the reliability and diagnostic value of the lever sign test.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

A total of 94 patients were recruited between November 2014 and July 2016. Patients were included if they were at least 16 years old, suffered from knee trauma, and had indications for knee arthroscopic surgery. Lever sign, anterior drawer, Lachman, and pivot-shift test outcomes were examined by an orthopaedic/trauma surgeon and a physical therapist. A test-retest design was used to investigate interrater reliability. Moreover, the lever sign test outcomes, alone and in combination with the other diagnostic tests, were compared with arthroscopic results, which served as the gold standard for the test’s diagnostic value.

Results:

The lever sign test and pivot-shift test had kappa values exceeding 0.80 for interrater reliability. The kappa values for the anterior drawer test and Lachman test were 0.80 and 0.77, respectively. The lever sign test showed the highest specificity (100%) and the lowest sensitivity (39%) when compared with the other 3 tests. Moreover, its positive and negative predictive values were 100% and 65%, respectively, while an accuracy of 71% was calculated. Clustering the lever sign test parallel with the other 3 tests resulted in the highest accuracy of 91%.

Conclusion:

The lever sign test appears to have high interrater reliability and is the most specific test, showing a maximal positive predictive value. A positive lever sign test result indicates an ACL rupture. These results support the added value of the lever sign test for diagnosing ACL ruptures.

Combined Anterior Cruciate Ligament Reconstruction and High Tibial Osteotomy in Anterior Cruciate Ligament-Deficient Varus Knees

Background

The presence of varus deformity in anterior cruciate ligament (ACL)-deficient knees can be a source of persistent knee pain owing to medial compartment overload. This deformity may threaten the outcome of ACL reconstruction because of increased tension on the graft.

Methods

In the period between June 2006 to January 2013, 12 patients with ACL deficiency and genu varus were treated by anatomical single bundle ACL reconstruction and open medial wedge high tibial osteotomy. The selected patients had manifestations of ACL deficiency in association with medial joint line pain with or without lateral thrust.

Results

Prospective evaluation using the International Knee Documentation Committee (IKDC) score was performed. The mean follow-up period was 56 months (range, 26–74 months). This technique achieved knee stability and realignment to normal values. The IKDC score has significantly improved from 37 (pre-operation) to 78 (post-operation) ( p<0.05).

Conclusion

The combined procedure of ACL reconstruction and high tibial osteotomy restored knee stability and reduced pain over the medial compartment. Although the combined procedure has a longer period of rehabilitation than an isolated ACL reconstruction, the elimination of lateral thrust and preservation of articular cartilage of the medial compartment are of paramount importance to the future of these knees.

Anatomic single-bundle anterior cruciate ligament reconstruction improves walking economy: hamstrings tendon versus patellar tendon grafts

PURPOSE

Anterior cruciate ligament (ACL) injury is associated with a pathologic gait pattern and increased energy cost during locomotion. ACL reconstruction could improve the gait pattern. Hamstrings tendon (HAM) and bone-patellar tendon-bone (BPTB) grafts are usually used for reconstruction. The aim of this study was to compare the efficacy of anatomic ACL reconstruction with HAM and BPTB grafts on improving and normalizing the energy cost and physiologic reserves during flat, uphill, and downhill walking.

METHODS

Twenty male subjects with unilateral ACL injuries were randomly assigned to ACL reconstruction with a HAM (n = 10) or BPTB (n = 10) graft. Ten matched controls were also enrolled. All participants performed three 8-min walking tasks at 0, +10, and -10 % gradients before and 9 months after surgery. Energy cost (oxygen consumption, VO₂), heart rate (HR), and ventilation (VE) were measured. Lysholm/IKDC scores were recorded.

RESULTS

Pre-operatively, VO₂, HR, and VE were higher in the HAM and BPTB groups than in controls during walking at 0, +10, and -10 % gradients (p < 0.001-0.01). Post-operatively, both HAM and BPTB groups showed reduced VO₂, HR, and VE during the three walking tasks (p < 0.001-0.01). Although the post-operative VO₂ in both surgical groups reached 90-95 % of the normative (control) value during walking, it remained elevated against the value observed in controls (p < 0.001-0.01). The HAM and BPTB groups showed no differences in post-surgical VO₂ or HR during walking at all three gradients.

CONCLUSION

Anatomic ACL reconstruction with either HAM or BPTB graft resulted in similar short-term improvements in energy cost and nearly normalized locomotion economy and cardiorespiratory reserves during flat, uphill, and downhill walking. The improved locomotion economy is an additional benefit of anatomic ACL reconstruction, irrespective of the type of graft used, that the orthopaedic surgeons should consider.

LEVEL OF EVIDENCE

II.

Hip Osteoarthritis: Etiopathogenesis and Implications for Management

Highly prevalent among the elderly, hip osteoarthritis (OA) carries a heavy burden of disease. Guidelines for the management of hip OA are often extrapolated from knee OA research, despite clear differences in the etiopathogenesis and response to treatments of OA at these sites. We propose that hip OA requires specific attention separate from other OA phenotypes. Our understanding of the etiopathogenesis of hip OA has seen significant advance over the last 15 years, since Ganz and colleagues proposed femoroacetabular impingement (FAI) as an important etiological factor. This narrative review summarizes the current understanding of the etiopathogenesis of hip OA and identifies areas requiring further research. Therapeutic approaches for hip OA are considered in light of the condition’s etiopathogenesis. The evidence for currently adopted management strategies is considered, especially those approaches that may have disease-modifying potential. We propose that shifting the focus of hip OA research and public health intervention to primary prevention and early detection may greatly improve the current management paradigm.

Curcumin slows osteoarthritis progression and relieves osteoarthritis-associated pain symptoms in a post-traumatic osteoarthritis mouse model

Background

Curcumin has been shown to have chondroprotective potential in vitro. However, its effect on disease and symptom modification in osteoarthritis (OA) is largely unknown. This study aimed to determine whether curcumin could slow progression of OA and relieve OA-related pain in a mouse model of destabilization of the medial meniscus (DMM).

Methods

Expression of selected cartilage degradative-associated genes was evaluated in human primary chondrocytes treated with curcumin and curcumin nanoparticles and assayed by real-time PCR. The mice subjected to DMM surgery were orally administered curcumin or topically administered curcumin nanoparticles for 8 weeks. Cartilage integrity was evaluated by Safranin O staining and Osteoarthritis Research Society International (OARSI) score, and by immunohistochemical staining of cleaved aggrecan and type II collagen, and levels of matrix metalloproteinase (MMP)-13 and ADAMTS5. Synovitis and subchondral bone thickness were scored based on histologic images. OA-associated pain and symptoms were evaluated by von Frey assay, and locomotor behavior including distance traveled and rearing.

Results

Both curcumin and nanoparticles encapsulating curcumin suppressed mRNA expression of pro-inflammatory mediators IL-1β and TNF-α, MMPs 1, 3, and 13, and aggrecanase ADAMTS5, and upregulated the chondroprotective transcriptional regulator CITED2, in primary cultured chondrocytes in the absence or presence of IL-1β. Oral administration of curcumin significantly reduced OA disease progression, but showed no significant effect on OA pain relief. Curcumin was detected in the infrapatellar fat pad (IPFP) following topical administration of curcumin nanoparticles on the skin of the injured mouse knee. Compared to vehicle-treated controls, topical treatment led to: (1) reduced proteoglycan loss and cartilage erosion and lower OARSI scores, (2) reduced synovitis and subchondral plate thickness, (3) reduced immunochemical staining of type II collagen and aggrecan cleavage epitopes and numbers of chondrocytes positive for MMP-13 and ADAMTS5 in the articular cartilage, and (4) reduced expression of adipokines and pro-inflammatory mediators in the IPFP. In contrast to oral curcumin, topical application of curcumin nanoparticles relieved OA-related pain as indicated by reduced tactile hypersensitivity and improved locomotor behavior.

Conclusion

This study provides the first evidence that curcumin significantly slows OA disease progression and exerts a palliative effect in an OA mouse model.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1025-y) contains supplementary material, which is available to authorized users.

MR T1ρ and T2 of meniscus after acute anterior cruciate ligament injuries

OBJECTIVE

To evaluate differences in meniscal T1ρ and T2 quantification in patients with acute anterior cruciate ligament (ACL) injuries and to determine correlations of these differences with MR morphological grading and patient-reported outcomes.

DESIGN

Bilateral knees of 52 patients with acute ACL injury and 20 healthy controls were scanned using 3 T magnetic resonance imaging (MRI) T1ρ and T2 mapping in this prospective study. Quantitative analysis of the meniscus was performed in anterior and posterior horns of the lateral and medial menisci. Morphological meniscal damage was assessed using modified whole-organ MRI scores (WORMS). Measurements were compared between injured, uninjured contralateral, and control knees using a mixed-effects regression model. Correlations between meniscal T1ρ/T2, WORMS and Knee Injury and Osteoarthritis Outcome Scores (KOOS) were examined using partial correlation analysis.

RESULTS

Mean meniscal T1ρ and T2 values were significantly higher in ACL-injured knees compared to control and contralateral knees. Menisci of ACL-injured knees without tears, including those limited to modified meniscal WORMS grade 0, also had significantly higher T1ρ and T2 values compared to menisci of uninjured knees. Within ACL-injured knees, T1ρ and T2 values showed significant positive associations with meniscal WORMS and significant negative associations with KOOS.

CONCLUSION

Acute ACL injuries are associated with significantly increased meniscal T1ρ and T2 values in both patients with and without meniscal lesions or tears, suggesting quantitative MRI provides more sensitive measures of meniscal differences compared to traditional morphological MRI sequences. Correlation between meniscal T1ρ/T2 and KOOS suggest that quantitative MRI is reflective of the extent of patients' clinical symptoms.

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.

Incidence of Secondary Intra-articular Injuries With Time to Anterior Cruciate Ligament Reconstruction

BACKGROUND

Precise locations of chondral and meniscal damage with increased time to anterior cruciate ligament reconstruction (ACLR) have not been well described.

PURPOSE/HYPOTHESIS

The purpose of the study was to determine the relationship between delay in primary ACLR and incidence of secondary intra-articular injury. The hypothesis was that patients with increased time between initial injury and ACLR will exhibit greater incidence of secondary intra-articular injury when compared with those who receive surgical intervention promptly after injury. A second hypothesis was that patients with higher preinjury activity levels or older age will exhibit greater secondary injury when compared with those with minimal preinjury activity levels and younger age.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review was performed on 1434 patients with an anterior cruciate ligament deficiency who underwent primary ACLR at a single institution between 2009 and 2013. Patients were grouped according to time to surgery after initial injury: 0-3, 4-12, and >12 months. Operative notes were used to analyze 10 variables across time-to-surgery groups: cartilage damage in the patella, trochlea, medial femoral condyle, lateral femoral condyle, medial tibial plateau, and lateral tibial plateau; medial and lateral meniscal injury; and the incidence of procedures involving either the meniscus or cartilage. Patient age and preinjury activity level were also analyzed for the 10 variables based on time-to-surgery groups.

RESULTS

An association was noted between time to surgery and increased incidence of injury in the trochlea, lateral femoral condyle, medial tibial plateau, and medial meniscus (P < .001). Different significant findings within each age group were observed, but overall positive findings were seen in the same 4 locations described above. On the basis of preinjury activity level, the less active patients were most at risk for medial meniscal and trochlear injury, while the more active patients were most at risk for medial tibial plateau injury with increased time from injury to ACLR.

CONCLUSION

Increasing time from injury to ACLR was associated with increased incidence of secondary injury seen in the trochlea, lateral femoral condyle, medial tibial plateau, and medial meniscus. Separate analyses of patient age and preinjury activity level showed similar findings, thus supporting the primary analysis.

Pathogenesis of post-traumatic OA with a view to intervention

Post-traumatic osteoarthritis (PTOA) subsequent to joint injury accounts for over 12% of the overall disease burden of OA, and higher in the most at-risk ankle and knee joints. Evidence suggests that the pathogenesis of PTOA may be related to inflammatory processes and alterations to the articular cartilage, menisci, muscle and subchondral bone that are initiated in the acute post-injury phase. Imaging of these early changes, as well as a number of biochemical markers, demonstrates the potential for use as predictors of future disease, and may help stratify patients on the likelihood of their developing clinical disease. This will be important in guiding future interventions, which will likely target elements of the inflammatory response within the joint, molecular abnormalities related to cartilage matrix degradation, chondrocyte function and subchondral bone remodelling. Until significant improvements are made, however, in identifying patients most at risk for developing PTOA--and therefore those who are candidates for therapy--primary prevention programmes will remain the most effective current management tools.

Knee laxity of Malaysian adults: gender differentials, and association with age and anthropometric measures

BACKGROUND

Knee laxity measurements have been shown to be associated with some medical conditions such as chronic joint pain and collagen tissue diseases. The aim of this study was to determine the effects of demographic factors and anthropometric measures on knee laxity.

MATERIALS AND METHODS

Data were collected from 521 visitors, staffs and students from the University Malaya Medical Centre and University of Malaya between December 2009 and May 2010. Knee laxity was measured using a KT-1000 arthrometer. Multiple regression analysis was used to find the association of knee laxity with age and anthropometric measures.

RESULTS

Using ANOVA, knee laxity did not show significant differences among ethnic groups for both genders. The average knee laxity in men was 3.47 mm (right) and 3.49 mm (left); while in women were 3.90 mm (right) and 3.67 mm (left). Knee laxity in women was significantly higher (right knee p<0.01 and left knee p<0.05) than men. Right knee laxity of men was negatively associated with height (p<0.05) and BMI (p<0.05); also a negative association was observed between left knee laxity and BMI (p<0.05). Overweight and obese men had less knee laxity than normal weight and underweight individuals. Elderly men and women (age 55 and above) had lower knee laxity (p<0.01) than young adults (ages 21-39).

CONCLUSION

These results suggest that age and body size are important factors in predicting knee laxity.

A review of anterior cruciate ligament injuries and reconstructive techniques. Part 2: Treatment

The aims of treatment of anterior cruciate ligament rupture are to eliminate pain, restore stability and allow early return to activity while preventing early degeneration. Ruptures can be treated conservatively, which requires careful patient selection and avoidance of high-risk activity. Each patient must be treated on an individual basis with consideration given to the level of activity, desire to return to sport, donor site morbidity and compliance with post-operative regimes. Through the evolution of single incision, arthroscopic anatomic reconstruction, our knowledge of the native anterior cruciate ligament anatomy and knee kinematics has progressed. The current gold standard uses four-stranded hamstring autograft with endobutton and interference screw fixation. Double-bundle reconstruction is technically challenging with greater risk and best reserved for larger knees with larger native ligaments. Although treatment has advanced considerably over the years, there are still a number of contentious issues which are considered in this review. Part two of this review discusses the short- and long-term objectives of surgery, the indications and timing of surgery, different graft materials, tunnel positions and rehabilitation programmes. We also evaluate the role of anatomical reconstruction and single- versus double-bundle anterior cruciate ligament reconstructions.