A prospective study to assess the outcomes of revision anterior cruciate ligament reconstruction

Failure modes after anterior cruciate ligament reconstruction: a systematic review and meta-analysis

PURPOSE

The reason for graft failure after anterior cruciate ligament reconstruction (ACLR) is multifactorial. Controversies remain regarding the predominant factor and incidence of failure aetiology in the literature. This review aimed to provide a meta-analysis of the literature to evaluate the relative proportion of various failure modes among patients with ACLR failure.

METHODS

The PubMed, Embase, Cochrane Library, Web of Science, and EBSCO databases were searched for literature on ACLR failure or revision from 1975 to 2021. Data related to causes for ACLR surgical failure were extracted, and a random effects model was used to pool the results, which incorporates potential heterogeneity. Failure modes were compared between different populations, research methods, graft types, femoral portal techniques, and fixation methods by subgroup analysis or linear regression. Funnel plots were used to identify publication bias and small-study effects.

RESULTS

A total of 39 studies were analyzed, including 33 cohort studies and six registry-based studies reporting 6578 failures. The results showed that among patients with ACLR failure or revision, traumatic reinjury was the most common failure mode with a rate of 40% (95% CI: 35-44%), followed by technical error (34%, 95% CI: 28-42%) and biological failure (11%, 95% CI: 7-15%). Femoral tunnel malposition was the most common cause of the technical error (29%, 95% CI: 18-41%), with more than two times higher occurrence than tibial tunnel malposition (11%, 95% CI: 6-16%). Traumatic reinjury was the most common factor for ACLR failure in European populations and in recent studies, while technical errors were more common in Asian populations, earlier studies, and surgery performed using the transtibial (TT) portal technique. Biological factors were more likely to result in ACLR failure in hamstring (HT) autografts compared to bone-patellar tendon-bone (BPTB) autografts.

CONCLUSION

Trauma is the most important factor leading to surgical failure or revision following ACLR. Technical error is also an important contributing factor, with femoral tunnel malposition being the leading cause of error resulting in failure.

Returning to Activity After Anterior Cruciate Ligament Revision Surgery: An Analysis of the Multicenter Anterior Cruciate Ligament Revision Study (MARS) Cohort at 2 Years Postoperative

BACKGROUND

Patients with anterior cruciate ligament (ACL) revision report lower outcome scores on validated knee questionnaires postoperatively compared to cohorts with primary ACL reconstruction. In a previously active population, it is unclear if patient-reported outcomes (PROs) are associated with a return to activity (RTA) or vary by sports participation level (higher level vs. recreational athletes).

HYPOTHESES

Individual RTA would be associated with improved outcomes (ie, decreased knee symptoms, pain, function) as measured using validated PROs. Recreational participants would report lower PROs compared with higher level athletes and be less likely to RTA.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

There were 862 patients who underwent a revision ACL reconstruction (rACLR) and self-reported physical activity at any level preoperatively. Those who did not RTA reported no activity 2 years after revision. Baseline data included patient characteristics, surgical history and characteristics, and PROs: International Knee Documentation Committee questionnaire, Marx Activity Rating Scale, Knee injury and Osteoarthritis Outcome Score, and the Western Ontario and McMaster Universities Osteoarthritis Index. A binary indicator was used to identify patients with same/better PROs versus worse outcomes compared with baseline, quantifying the magnitude of change in each direction, respectively. Multivariable regression models were used to evaluate risk factors for not returning to activity, the association of 2-year PROs after rACLR surgery by RTA status, and whether each PRO and RTA status differed by participation level.

RESULTS

At 2 years postoperatively, approximately 15% did not RTA, with current smokers (adjusted odds ratio [aOR] = 3.3; P = .001), female patients (aOR = 2.9; P < .001), recreational participants (aOR = 2.0; P = .016), and those with a previous medial meniscal excision (aOR = 1.9; P = .013) having higher odds of not returning. In multivariate models, not returning to activity was significantly associated with having worse PROs at 2 years; however, no clinically meaningful differences in PROs at 2 years were seen between participation levels.

CONCLUSION

Recreational-level participants were twice as likely to not RTA compared with those participating at higher levels. Within a previously active cohort, no RTA was a significant predictor of lower PROs after rACLR. However, among patients who did RTA after rACLR, approximately 20% reported lower outcome scores. Most patients with rACLR who were active at baseline improved over time; however, patients who reported worse outcomes at 2 years had a clinically meaningful decline across all PROs.

The Efficacy and Outcome of a Two-Staged Operation for Irreducible Knee Dislocation: A Prospective Short-Term Follow-Up

Background: Irreducible knee dislocation (IKD) is a very rare but serious type of knee dislocation; it can lead to soft tissue necrosis due to incarceration of the medial structures and faces great difficulty in the postoperative rehabilitation, too. IKD needs careful pre-operative planning. There is no universal agreement about the appropriate surgical strategy for IKD. The purpose of this study was to investigate the clinical efficacy, safety, and outcome of the two-staged operation in treatment of IKD. Methods: IKD patients were included from June 1, 2016 to May 31, 2020. In the stage-1 surgery, acute reduction and extra-articular structure repair were performed. Following an intermediate rehabilitation, delayed cruciate ligament reconstructions were performed in stage-2. Physical examination, CT, MRI, and X-ray were performed during the pre-operative period. Knee function, joint stability, ligament laxity, knee range of motion (ROM), and alignment were accessed at follow-ups. The minimum and maximum follow-up times were 0.5 years and 1 year, respectively. Results: In total, 17 IKD patients were included. There were three subjects (17.65%) missing at the 1 year follow-up and the average follow-up was 11.18 ± 2.53 months. After stage-1, normal alignment and superior valgus/varus stability were restored in most subjects; however, a notable anterior-posterior instability still existed in most patients. The intermediate rehabilitation processed smoothly (6.94 ± 1.20 weeks), and all patients achieved knee ROM of 0-120° finally. At 0.5 years and 1 year follow-up after stage-2, all subjects had achieved normal knee stability, ROM, and satisfying joint function. No infection or DVT was observed. Conclusions: The two-staged operation for IKD has superior efficacy on knee stability and function, and it can facilitate the rehabilitation and achieve satisfactory short-term outcome.

Trauma and femoral tunnel position are the most common failure modes of anterior cruciate ligament reconstruction: a systematic review

PURPOSE

To improve outcomes of anterior cruciate ligament reconstruction (ACLR), it is important to understand the reasons for failure of this procedure. This systematic review was performed to identify current failure modes of ACLR.

METHODS

A systematic search was performed using PubMed, EMBASE, Cochrane, and annual registries for ACLR failures. Studies were included when failure modes were reported (I) of ≥ 10 patients and (II) at a minimum of two-year follow-up. Modes of failure were also compared between different graft types and in femoral tunnel positions.

RESULTS

This review included 24 cohort studies and 4 registry-based studies (1 level I, 1 level II, 10 level III, and 16 level IV studies). Overall, a total of 3657 failures were identified. The most common single failure mode of ACLR was new trauma (38%), followed by technical errors (22%), combined causes (i.e. multiple failure mechanisms; 19%), and biological failures (i.e. failure due to infection or laxity without traumatic or technical considerations; 8%). Technical causes also played a contributing role in 17% of all failures. Femoral tunnel malposition was the most common cause of technical failure (63%). When specifically looking at the bone-patellar tendon-bone (BPTB) or hamstring (HT) autografts, trauma was the most common failure mode in both, whereas biological failure was more pronounced in the HT group (4% vs. 22%, respectively). Technical errors were more common following transtibial as compared to anteromedial portal techniques (49% vs. 26%).

CONCLUSION

Trauma is the single leading cause of ACLR failure, followed by technical errors, and combined causes. Technical errors seemed to play a major or contributing role in large part of reported failures, with femoral tunnel malposition being the leading cause of failure. Trauma was also the most common failure mode in both BPTB and HT grafts. Technical errors were a more common failure mode following transtibial than anteromedial portal technique.

LEVEL OF EVIDENCE

IV.

Return to sport activity after anterior cruciate ligament reconstruction: A 6-10 years follow-up

BACKGROUND

Nowadays, patients widely accept anterior cruciate ligament (ACL) reconstructive surgery. However, its long-term complications are still under investigation in athletes. Therefore, the aim of this study was to evaluate long-term ACL reconstruction especially in athletes.

METHODS

A total of 426 patients with ACL injury were studied during 2008-2012. Demographic characteristics (gender, age, BMI), graft type, chondral lesion, osteoarthritis, meniscus tear, exercise activity, and pain intensity were noted. The effects of these factors on the return to sport activity after ACL reconstruction were also investigated. Lachman test, KT-1000, ACL quality of life (ACL-QOL), KOOS score, IKDC, and LKS were assessed at 2 years post-operation and at final follow-up. Repeated ACL rupture on the same and contralateral sides were also evaluated.Results: knee stability (based on Lachman and KT-1000), knee function (according to KOOS, LKS, and IKDC scores) and ACL-QOL were improved during the 2 years follow-up. The rate of return to sport activity similar to preinjury in patients was 64.08% in final follow-up. Chondral lesion was a limiting factor among the variables that affected the return to sport activity. It caused a return to sport activity similar to pre injury just in 21.24% of the patients. However, meniscus rupture did not affect return to sport activity similar to pre injury. Also, the rate of return to sport activity similar to pre injury was higher in men, patients under 30 years and those who had BMI of 20-25 kg/m². In final follow-up, risk of ACL rupture in the injured knee and contralateral knee was 4.22% and 10.57%, respectively.

CONCLUSION

Despite the recovery of patients after ACL reconstruction during long-term follow-up in athletes, return to sport activity similar to pre-injury in female, older peoples, overweight patients and athletes with chondral lesion were lower. However, these conditions do not apply to the meniscus rupture.

The influence of tibial slope on anterior cruciate ligament graft failure risk is dependent on graft positioning

BACKGROUND

Increased lateral tibial posterior slope (LTPS) is associated with higher anterior cruciate ligament (ACL) reconstruction (ACLR) failure rate. Transportal central femoral footprint ACLR is associated with higher failure rate compared to transtibial high anteromedial footprint ACLR due to graft anisometry. The purpose of this study was to investigate whether the influence of tibial slope on ACL graft failure risk is dependent on graft positioning.

MATERIAL

Of the 1480 consecutive hamstring ACLRs, 30 transportal (central femoral tunnel placement) and 30 transtibial (high anteromedial tunnel placement) ACLR failures were evaluated and matched one-to-one with non-failure control participants by age, sex, graft and surgical technique. Lateral tibial slope was assessed on MRI.

RESULTS

The risk of graft failure in the transportal group increased by 40.5% per degree of increasing LTPS (odds ratio 1.4; 95% confidence interval 1.05-1.87; p = 0.02). The transportal failure group showed a significantly higher mean tibial slope of 8.6° compared to both the transportal control group with 7.1° ( p = 0.03) and the transtibial failure group with 7.2° ( p = 0.04). Increased tibial slope was associated with shorter time to reconstruction failure ( p = 0.002). The difference between slopes in the transtibial failure group (7.2°) compared to the transtibial control group (7.1°) was not significant ( p = 0.56).

CONCLUSION

Increased LTPS is associated with significantly increased risk of graft failure only in transportal ACLR, not in transtibial ACLR. Slope-related graft strain may be potentiated by anisometric ACL graft placement.

Anthropometric correlation with hamstring graft size in anterior cruciate ligament reconstruction among males

PURPOSE

Pre-operative knowledge of hamstring graft size for anterior cruciate ligament reconstruction (ACL) is of clinical importance and useful in making appropriate decisions about graft choice. This study investigated if there is any correlation between anthropometric measurements such as height, weight, body mass index, thigh length, and circumference with the size of hamstring tendon graft in anterior cruciate ligament reconstruction.

METHODS

The anthropometric data of 50 consecutive adult males, who underwent primary ACL reconstruction using quadruple hamstring autograft, were collected prospectively. Data analysis using Pearson's correlation test was performed and multiple logistic regression analysis was used to investigate any correlation not detected by Pearson's test and to eliminate confounders.

RESULTS

Patient's height and thigh length demonstrated a positive correlation with gracilis graft length (r = .464, P = .001, r = .456, P = .001, respectively) and semitendinosus graft length (r = .541, P = 000, r = .578, P = .000, respectively). While the patient's age was the only independent factor which had a positive correlation with the quadrupled hamstring graft diameter (r = .412, P = .004), multiple regression analysis showed abdominal girth had a significant negative correlation with gracilis (P = .04) and semitendinosus (P = .006) graft thickness.

CONCLUSION

This study demonstrated that some anthropometric measurements had a positive correlation with the hamstring graft length and diameter in male patients. Hence, these results provide preliminary support for the use of some anthropometric measurements in the preoperative planning and prediction of the hamstring graft length and diameter in anterior cruciate ligament reconstruction.

Anthropometric correlation with hamstring graft size in anterior cruciate ligament reconstruction among males

PURPOSE

Pre-operative knowledge of hamstring graft size for anterior cruciate ligament reconstruction (ACL) is of clinical importance and useful in making appropriate decisions about graft choice. This study investigated if there is any correlation between anthropometric measurements such as height, weight, body mass index, thigh length, and circumference with the size of hamstring tendon graft in anterior cruciate ligament reconstruction.

METHODS

The anthropometric data of 50 consecutive adult males, who underwent primary ACL reconstruction using quadruple hamstring autograft, were collected prospectively. Data analysis using Pearson's correlation test was performed and multiple logistic regression analysis was used to investigate any correlation not detected by Pearson's test and to eliminate confounders.

RESULTS

Patient's height and thigh length demonstrated a positive correlation with gracilis graft length (r = .464, P = .001, r = .456, P = .001, respectively) and semitendinosus graft length (r = .541, P = 000, r = .578, P = .000, respectively). While the patient's age was the only independent factor which had a positive correlation with the quadrupled hamstring graft diameter (r = .412, P = .004), multiple regression analysis showed abdominal girth had a significant negative correlation with gracilis (P = .04) and semitendinosus (P = .006) graft thickness.

CONCLUSION

This study demonstrated that some anthropometric measurements had a positive correlation with the hamstring graft length and diameter in male patients. Hence, these results provide preliminary support for the use of some anthropometric measurements in the preoperative planning and prediction of the hamstring graft length and diameter in anterior cruciate ligament reconstruction.

Revision Anterior Cruciate Ligament Reconstruction in the Nonathlete Population

BACKGROUND

There is considerable literature about revision anterior cruciate ligament (ACL) reconstruction in athletes vut there is little published evidence about the same in the nonathletes. The injury itself may remain underdiagnosed and untreated in nonsports persons. This study highlights the high incidence of ACL injury in the nonathletic patient cohort, revision rates, and the outcomes of revision ACL reconstruction.

MATERIALS AND METHODS

856 nonathletic patients who underwent primary ACL reconstruction were included in this retrospective study. Patients were asked on phone whether they had undergone revision surgery and whether they had symptoms severe enough to seek reintervention. Clinical assessment and preoperative and postoperative International Knee Documentation Committee (IKDC) and Lysholm scoring were used to followup patients who underwent revision intervention.

RESULTS

Clinically, symptomatic revision rate was 5.9% (51 out of 856 patients), and 33 out of these 856 patients (3.9%) underwent revision ACL reconstruction. The reasons for revision were rupture of the previous graft in 21 and laxity (incompetence) of the graft in 12 patients. The mean preoperative and postoperative IKDC scores were 44.1 and 69.8, respectively, and the improvement was statistically significant (P < 0.001). The IKDC score following revision ACL reconstruction was significantly better in those patients who underwent revision <1 year following the onset of recurrent symptoms (P = 0.015). Meniscal tears were present in 47.6%, and chondral injuries were seen in 33.3% of patients. The tibial tunnel positioning was abnormal in 70% of patients. Femoral tunnel positioning was aberrant in all the patients.

CONCLUSIONS

The revision rate of primary ACL reconstruction of 5.9% in nonathletes and revision ACL reconstruction rate of 3.9% are similar to the reported revision rates of 2.9%-5.8% in athletic patients. Similar to athletes, suboptimal tunnel placement is the major contributor to failure in nonathletes also.

The Ratio of Tibial Slope and Meniscal Bone Angle for the Prediction of ACL Reconstruction Failure Risk

Background  A growing body of research is indicating that the tibial slope and the geometry of the tibiofemoral meniscal-cartilage interface may affect the risk of anterior cruciate ligament reconstruction (ACLR) failure. Increased lateral tibial posterior slope (LTPS) and reduced meniscal bone angle (MBA) are associated with increased risk of anterior cruciate ligament (ACL) injury. The significance of a LTPS-MBA ratio regarding the prediction of ACL failure risk remains unknown. As LTPS and MBA may eventually potentiate or neutralize each other, it is expected that a low LTPS-MBA ratio is associated with high chance of ACL graft survival while a high LTPS-MBA ratio is associated with high risk of ACL failure. Material and Methods  Out of 1,487 consecutive patients who underwent hamstring ACLR between August 2000 and May 2013, 54 ACLR failures with intact lateral menisci were included in this study and matched one-to-one with 54 control participants by age, sex, graft, surgical technique, and graft fixation method. Control participants had undergone ACLR without signs of lateral meniscal injury, graft failure, or insufficiency. MBA and LTPS were assessed on magnetic resonance imaging. Logistic regression was used to identify LTPS/MBA key cut-off ratios. Results  In this cohort, a LTPS-MBA ratio under 0.27 was associated with a 28% risk of ACLR failure (36% of patients), while a ratio exceeding 0.42 was associated with an 82% risk of ACLR failure (31% of patients). The odds of ACL failure increased by 22.3% per reduction of 1 degree in MBA (odds ratio [OR], 1.22; 95% limits, 1.1-1.34). No significant association was found between LTPS and the risk of ACL graft failure in transtibial ACLR, while the odds of ACL failure increased by 34.9% per degree of increasing LTPS in transportal ACLR (OR, 1.34; 95% limits, 1.01-1.79). No significant correlation was found between MBA and LTPS ( p  = 0.5). Conclusion  Reduced MBA was associated with significantly increased risk of ACL graft failure. A ratio of LTPS and MBA was found to be useful for the prediction of ACLR failure risk and may preoperatively help to identify patients at high risk of ACLR failure. This may have implications for patient counseling and the indication of additional extra-articular stabilizing procedures.

Clinical Outcomes in Revision Anterior Cruciate Ligament Reconstruction: A Meta-analysis

PURPOSE

The purpose of this meta-analysis was to determine overall objective graft failure rate, failure rate by graft type (allograft vs autograft reconstruction), instrumented laxity, and patient outcome scores following revision anterior cruciate ligament (ACL) reconstruction. Outcomes of interest were collected for all studies meeting the study inclusion criteria, but lower-level studies (level III/IV) were not pooled for quantitative synthesis due to high levels of heterogeneity in these study populations.

METHODS

A comprehensive search strategy was performed to identify studies reporting outcomes of revision ACL reconstruction. The primary outcome reported was graft failure. A meta-analysis comparing rate of failure by graft type was conducted using a random effects model. Studies also reported patient clinical outcome scores, including International Knee Documentation Committee (IKDC), Lysholm, and knee injury and osteoarthritis outcome scores (KOOS) and graft laxity.

RESULTS

Eight studies with 3,021 patients (56% male, 44% female) with an average age of 30 ± 4 years and mean follow-up time of 57 months were included. The overall objective failure rate was 6% (95% confidence interval [CI], 1.8%-12.3%). Mean instrumented laxity as side-to-side difference was 2.5 mm (95% CI, 1.9-3.1 mm). Mean IKDC subjective score was 76.99 (95% CI, 76.64-77.34), mean KOOS symptoms score was 76.73 (95% CI, 75.85-77.61), and mean Lysholm score was 86.18 (95% CI, 79.08-93.28). The proportion of patients with IKDC grade A or B was 85% (95% CI, 77%-91%). When the available data for failure rate were analyzed by graft type, autograft reconstruction had a failure rate of 4.1% (95% CI, 2.0%-6.9%), similar to allograft reconstruction at 3.6% (95% CI, 1.4%-6.7%).

CONCLUSIONS

In this meta-analysis, revision ACL reconstruction had failure rates similar to autograft or allograft reconstruction. Overall outcome scores for revision reconstruction have improved but appear modest when compared with primary ACL reconstruction surgery.

LEVEL OF EVIDENCE

Meta-analysis of Level II studies, Level II.

Anthropometric and Skeletal Parameters Predict 2-Strand Semitendinosus Tendon Size in Double-Bundle Anterior Cruciate Ligament Reconstruction

Background:

Few studies have examined whether skeletal parameters predict hamstring graft size during anterior cruciate ligament reconstruction (ACLR).

Purpose/Hypothesis:

The purpose of this study was to examine whether preoperative anthropometric and radiographic skeletal parameters could predict hamstring graft size during ACLR. We hypothesized that both anthropometric and skeletal parameters can be used to predict graft size in our double-bundle procedure and that the use of skeletal parameters will improve the accuracy of graft size prediction.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 200 patients were recruited and underwent double-bundle ACLR using a semitendinosus (ST) graft. The harvested tendon was measured to determine graft length (GL) and then split at its midpoint. The graft diameters of the anteromedial (GD_AM) and posterolateral bundles (GD_PL) were measured at the femoral aspect of the 2-stranded graft. The mean diameters of both bundles were included in the analysis. On the coronal radiograph, femorotibial angle (FTA), femoral interepicondylar distance (IED), and tibial plateau width (coronal tibial width [CTW]) were measured. Blumensaat line length (BLL) and the lateral tibial width (LTW) were measured on the lateral radiograph. A linear regression analysis was conducted using graft size as the dependent variable and age, sex, height, weight, Tegner activity score, and skeletal parameters as the independent variables.

Results:

Mean GL was 258.9 ± 21.9 mm, GD_AM was 5.9 ± 0.5 mm, and GD_PL was 5.7 ± 0.6 mm. Single regression analysis showed that GL was significantly predicted by sex, height, weight, Tegner activity score, IED, CTW, BLL, and LTW (R² range, 0.033-0.342). GD was predicted by sex, height, weight, IED, CTW, BLL, and LTW (R² range, 0.094-0.207). Stepwise multiple linear regression analysis significantly confirmed sex, height, and age as the variables to comprehensively predict GL (R² = 0.384). With regard to GD, stepwise multiple regression confirmed height and IED as significant variables (R² = 0.224).

Conclusion:

Both preoperative anthropometric and radiographic parameters on plain radiographs were able to predict harvested GL and 2-strand GD. Multivariate regression slightly improved the prediction of graft dimensions compared with univariate regression.

Are pre-operative anthropometric parameters helpful in predicting length and thickness of quadrupled hamstring graft for ACL reconstruction in adults? A prospective study and literature review

PURPOSE

Cross-sectional diameter of 7 mm or more of graft in anterior cruciate ligament reconstruction is arguably the single most important factor determining the success of the operation. Pre-operative anthropometric parameters have been reported to correlate with diameter of quadrupled hamstring graft, which is the most popular graft choice today. We conducted this prospective study to determine the value of some anthropometric measurements to predict the length of harvested semitendinosus and gracilis tendons and quadrupled hamstring graft diameter. We also assessed the reliability of the mathematical equation in accurately predicting the graft diameter.

METHODS

Height, weight, BMI and thigh length of 160 patients who underwent primary ACL reconstruction was measured before surgery. Using multivariate logistic regression analysis length of harvested semitendinous and gracilis tendons along with quadrupled graft diameter were correlated to height, weight, BMI and thigh length.

RESULTS

Ninety-six percent had graft diameter of 7 mm or more. Height and thigh length were found to be most strongly correlating to both the length of harvested tendons and the quadrupled graft diameter (p ≤ 0.001, r = 0.25-0.39). Patients with height less than 147 cm were found to be at highest risk for inadequate graft diameter (less than 7 mm). Although the anthropometric parameters were found to be significantly related to height and thigh length, the strength of association is moderate. The mathematical equation for prediction of graft diameter using height was found to inaccurately over-predict the graft diameter in 33.1 % of cases, assessed using Bland-Altman plot.

CONCLUSION

Anthropometric parameters, especially height and thigh length, can serve as a guide to plan hamstring graft diameter and length before ACL reconstruction. But, it is not advisable to rely on mathematical equations for absolute values of graft parameters as there is risk of over-estimating hamstring length or graft thickness.

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

Background:

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

Purpose:

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

Study Design:

Case series; Level of evidence, 4.

Methods:

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

Results:

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

Conclusion:

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

Revision anterior cruciate ligament reconstruction: clinical outcome and evidence for return to sport

PURPOSE

An increasing number of patients undergo revision anterior cruciate ligament (ACL) reconstruction, with the intention of returning to sport being a major indication. The aim of this study is to assess the available evidence for clinical improvement and return to sport, to understand the real potential of this procedure in regaining functional activity, and to facilitate improved counselling of patients regarding the expected outcome after revision ACL reconstruction.

METHODS

The search was conducted on the PubMed database. Articles reporting clinical results for revision ACL reconstruction were included. A meta-analysis was performed on return to sport, and results were compared to the literature on primary ACL reconstruction. Other specific clinical outcomes (Lysholm, Tegner, IKDC Objective scores) were also included in the meta-analysis.

RESULTS

Of the 503 identified records, a total of 59 studies involving 5365 patients were included in the qualitative data synthesis. Only 31 articles reported the rate of return to sport. Whereas 73 % of good objective results and satisfactory subjective results were documented, 57 % of patients did not return to the same level of sport activity, significantly inferior to that of a primary procedure.

CONCLUSION

The real potential of revision ACL reconstruction should not be overestimated due to the low number of patients able to return to their previous activity level, significantly inferior with respect to that reported for primary ACL reconstruction. This finding will help physicians in the clinical practice providing realistic expectations to the patients. Future studies should focus on participation-based outcome measures such as return to sport and in strategies to improve the results in terms of return to previous activities after revision ACL reconstruction.

LEVEL OF EVIDENCE

Systematic review and meta-analysis including Level IV studies, Level IV.

Lateral Tibial Posterior Slope Is Increased in Patients With Early Graft Failure After Anterior Cruciate Ligament Reconstruction

BACKGROUND

The lateral tibial posterior slope (LTPS) has been reported in multiple studies to correlate with an increased risk for native anterior cruciate ligament (ACL) tearing. To date, no study has examined the effect of an increased LTPS as measured on magnetic resonance imaging (MRI) on the likelihood of ACL graft failure.

HYPOTHESIS

An increased LTPS as measured on MRI would correlate with an increased risk for ACL graft failure.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Fifty-eight patients were initially identified who experienced graft failure after primary ACL reconstruction and underwent revision between 1998 and 2009. Exclusion criteria were clinical follow-up of less than 4 years, graft failure occurring greater than 2 years after primary surgery, skeletal immaturity, deep infection, lack of available preoperative MRI, and history of trauma to the proximal tibia. This left 35 patients with early (within 2 years) failure of primary ACL reconstruction. These patients were matched to 35 control participants who had undergone ACL reconstruction with a minimum of 4 years of clinical follow-up and no evidence of graft failure. Patients were matched by age, sex, date of primary surgery, and graft type. The LTPS was then determined on MRI in a blinded fashion.

RESULTS

The mean time to failure in patients in the study group was 1 year (range, 0.6-1.4 years). The mean follow-up of those in the matched control group was 6.9 years (range, 4.0-13.9 years). The mean LTPS in the early ACL failure group was found to be 8.4°, which was significantly larger than that in the control group at 6.5° (P = .012). The odds ratio for graft failure considering a 2° increase in the LTPS was 1.6 (95% CI, 1.1-2.2) and continued to increase to 2.4 (95% CI, 1.2-5.0) and 3.8 (95% CI, 1.3-11.3) with 4° and 6° increases in the LTPS, respectively. No significant association was identified between graft type and graft failure.

CONCLUSION

An increased LTPS is associated with an increased risk for early ACL graft failure, regardless of graft type. Orthopaedic surgeons should consider measuring the LTPS as part of the preoperative assessment of ACL-injured patients.

Are pre-operative anthropometric parameters helpful in predicting length and thickness of quadrupled hamstring graft for ACL reconstruction in adults? A prospective study and literature review

PURPOSE

Cross-sectional diameter of 7 mm or more of graft in anterior cruciate ligament reconstruction is arguably the single most important factor determining the success of the operation. Pre-operative anthropometric parameters have been reported to correlate with diameter of quadrupled hamstring graft, which is the most popular graft choice today. We conducted this prospective study to determine the value of some anthropometric measurements to predict the length of harvested semitendinosus and gracilis tendons and quadrupled hamstring graft diameter. We also assessed the reliability of the mathematical equation in accurately predicting the graft diameter.

METHODS

Height, weight, BMI and thigh length of 160 patients who underwent primary ACL reconstruction was measured before surgery. Using multivariate logistic regression analysis length of harvested semitendinous and gracilis tendons along with quadrupled graft diameter were correlated to height, weight, BMI and thigh length.

RESULTS

Ninety-six percent had graft diameter of 7 mm or more. Height and thigh length were found to be most strongly correlating to both the length of harvested tendons and the quadrupled graft diameter (p ≤ 0.001, r = 0.25-0.39). Patients with height less than 147 cm were found to be at highest risk for inadequate graft diameter (less than 7 mm). Although the anthropometric parameters were found to be significantly related to height and thigh length, the strength of association is moderate. The mathematical equation for prediction of graft diameter using height was found to inaccurately over-predict the graft diameter in 33.1 % of cases, assessed using Bland-Altman plot.

CONCLUSION

Anthropometric parameters, especially height and thigh length, can serve as a guide to plan hamstring graft diameter and length before ACL reconstruction. But, it is not advisable to rely on mathematical equations for absolute values of graft parameters as there is risk of over-estimating hamstring length or graft thickness.

Functional outcome of septic arthritis after anterior cruciate ligament surgery

PURPOSE

Septic arthritis is a rare complication after cruciate ligament surgery. The lack of conclusive evidence makes it difficult to obtain a consensus concerning the best treatment option.

METHODS

From June 1993 to May 2010, 31 patients met the inclusion criteria for this prospective case series. The average age at ACL injury was 33.5 years. Treatment protocol was based on the grade of infection. Options included arthroscopic treatment for infections of Gaechter grades 1 and 2 or arthrotomy for infections of grades 3 and 4. Graft retention was decided based on the clinical findings. The setting was a specialized trauma hospital. Follow-up included International Knee Documentation Committee (IKDC) forms, Tegner score, and Lysholm scores at a mean of six years (71 months; range, 13-140) after treatment.

RESULTS

In all cases, treatment of infection was successful; overall, a mean of 2.6 operations were required. In eight cases, it was possible to salvage the graft. The Tegner activity level before the knee injury was 6.5 points. At follow-up, the average score was 4.5 points. The postoperative subjective IKDC score averaged 63. The mean Lysholm score was 63.9. On clinical examination, a mean extension deficit of 2.5° and a mean maximum flexion of 121° were found. In the single-legged hop test, a mean capacity of 68% compared with the uninjured side was measured.

CONCLUSION

The stage-adapted procedure gives reliable results for septic arthritis after ACL surgery. There were no recurrences of septic arthritis or bone infection. Early infection can be managed arthroscopically with satisfactory results. More advanced infections should be addressed with a more radical approach. In conclusion, functional outcome in most of the presented cases was only fair compared with results from ACL surgery not complicated by infection.

Functional assessment of combined reconstruction of the anterior cruciate ligament and posterolateral corner with a single femoral tunnel: a two-year minimum follow-up

PURPOSE

A technique for combined reconstruction of the anterior cruciate ligament (ACL) and posterolateral corner (PLC) with a single femoral tunnel was recently described. This technique aims to avoid tunnel confluence in the lateral femoral condyle. Because there have been no studies on the functional outcomes and possible complications of this technique, our goal is to demonstrate a two-year minimum follow-up of patients who underwent this type of reconstruction.

METHODS

Nine patients were prospectively evaluated. The ACL was reconstructed with an anatomic single bundle, and the PLC structures reconstructed were the lateral collateral ligament, the popliteus tendon, and the popliteofibular ligament. Patients were evaluated using the objective and subjective International Knee Documentation Committee (IKDC) and the Lysholm and Tegner scales before and after the surgical procedure.

RESULTS

The mean follow-up period of the studied patients was 27.3 months. The mean subjective IKDC score rose from 43.6 to 84.0, and the Lysholm score rose from 62.1 to 90.8. In the final assessment, six patients were classified as IKDC A and three as IKDC B. According to the Tegner scale, five patients were able to return to their level of activity prior to the injury. There were no reconstruction failures. One patient experienced postoperative infection and pain in the lateral scar.

CONCLUSIONS

The results of the reconstruction of ACL injuries associated with PLC with a single femoral tunnel produced a good functional outcome and a low incidence of complications.