Revision anterior cruciate ligament surgery: experience from Miami

Peroneus longus tendon autograft versus allograft in revision ACLR: A retrospective comparison

PURPOSE

The use of peroneus longus tendon (PLT) autografts in primary anterior cruciate ligament reconstruction (ACLR) has increased recently, but there is a lack of research on its use in revision ACLR. This study aimed to compare the clinical outcomes and complications between revision ACLR using allografts and PLT autografts.

MATERIALS AND METHODS

Fifty-nine patients who underwent arthroscopic revision of ACLR with complete clinical follow-ups between 2012 and 2021 were retrospectively reviewed. Allograft was used in 44 of these patients, and PLT autograft was used in 15 of them. Lysholm knee score, Tegner activity score, Lachman, and anterior drawer tests were performed after a mean follow-up of 60months (range: 19-116). The American Orthopaedic Foot and Ankle Society (AOFAS) scale was used to evaluate the donor ankle functions. Clinical outcomes and complications were compared between groups.

RESULTS

Both groups showed significantly improved functional outcomes compared to their preoperative assessments. However, both groups had similar clinical results at the final follow-up, including Lysholm knee score, Tegner activity scale, knee range of motion, return to sports, time to return to daily activities, and rate of re-rupture. No major complications were seen in any of the patients. The AOFAS score was 99.13±2.64 in the PLT autograft group without loss of ankle muscle strength, deformity, instability, and permanent iatrogenic neurovascular injuries. The cumulative cost of the allograft group was significantly higher than the PLT autograft group.

CONCLUSIONS

The PLT autograft might be an alternative autograft option to allografts due to similar clinical outcomes, low donor site morbidity, and reduced cost in ACLR revisions, especially if the primary ACLR was performed using grafts harvested around the knee.

LEVEL OF EVIDENCE

III; retrospective comparative study.

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.

Good Short-Term Clinical Outcomes and Low Rates of Return to Sports after Repeat Revision ACL Reconstruction

Repeat revision anterior cruciate ligament reconstruction (ACL-R) is a rare, demanding procedure and, as such, has not been well studied. Most of the available literature shows improved functional outcomes compared with preoperative state but inferior results when compared with primary ACL-R, particularly regarding return to preinjury level of sports. The purpose of this study was to assess functional outcomes in patients who had undergone repeat revision ACL-R. The secondary aims were to register return to sports, associated meniscal and/or chondral lesions, and evaluate radiological anatomical parameters. Nine patients between 2011 and 2017 were evaluated, who had a minimum follow-up of 2 years. Median age at repeat ACL-R was 32 years (interquartile range [IQR], 30-34 years) and the median follow-up was 27 months (IQR, 24-39 months). Data collected prior to surgery and at last follow-up included patient demographics, operative findings, physical examination findings including pivot shift and KT-1000 arthrometer measurement; Lysholm and International Knee Documentation Committee (IKDC) subjective scores; and return to sports and level using the Tegner score. Knee Injury and Osteoarthritis Outcome Score (KOOS) subjective score and radiographic anatomical parameters were recorded at last follow-up. Mean IKDC and Lysholm score improvement was 25 points (confidence interval [CI] 12-37) and 25 points (CI 11-39), respectively (p < 0.001). The median postoperative KOOS score was pain: 93 (IQR, 64-96); symptoms: 94 (IQR, 83-97); activities of daily life: 96 (IQR, 90-100); sports: 75 (IQR, 50-90); and quality of life: 50 (IQR, 43-81). Postoperative median side-to-side KT-1000 arthrometer difference was 2 mm (IQR, 1-8 mm). The median radiographic posterior tibial slope was 10 degrees (IQR, 9-10). One patient was considered a failure at 16 months postoperative. Only 44% (four out of nine) patients were able to return to their sports. None of these patients had a cartilage injury, while three out of five patients who did not return to their sports had International Cartilage Regeneration & Joint Preservation Society grade III or IV cartilage injury. Patients should be counseled on the challenging outcomes of repeat revision ACL-R. This is Level IV, therapeutic case series.

Patient-Reported Outcomes After Multiple-Revision ACL Reconstruction: Good but Not Great

Purpose

To evaluate the patient-reported and objective functional outcomes of patients undergoing multiple-revision anterior cruciate ligament (ACL) reconstruction surgery. The secondary purpose was to determine failure rates and factors associated with failure, with a focus on posterior tibial slope.

Methods

All patients who underwent a repeat revision ACL reconstruction with a single surgeon over a 13-year period were identified. Chart data were obtained, including radiographic findings, operative details and findings, and postoperative examination findings. Failure was defined as subjective instability with evidence of graft incompetence on physical examination and MRI. Patients completed the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC-SKF) and Tegner Activity Level Scale. Patients who had outcomes scores completed a minimum of 2 years postoperatively were included.

Results

Fourteen patients were available for follow-up; 12 underwent secondary revision procedures, and 2 underwent tertiary revisions. Three patients (21%) had subsequent failure of the revision graft with mean time to failure of 27 months. Posterior tibial slope was significantly higher in the failures than in the nonfailures (13.3˚; 95% CI 10.1-16.6 versus 10.1˚; 95% CI 6.7-11.4; P = 0.049). Eleven patients completed outcomes measures at a mean of 42 months postoperatively (range 24-79 months). The mean Tegner activity score was 6.3 at follow-up, compared with 8.3 prior to the original ACL injury. The mean IKDC-SKF score was 70 at follow-up.

Conclusion

Multiple revision ACL reconstruction surgery appears to have reasonable functional outcomes but is associated with a relatively high failure rate. Activity level following repeat revision surgery is diminished compared to the preinjury state, but most patients are able to return to recreational sports.

Level of Evidence

Therapeutic Study, Level IV.

Increased Radiographic Posterior Tibial Slope Is Associated With Subsequent Injury Following Revision Anterior Cruciate Ligament Reconstruction

Background:

Increased posterior tibial slope has been identified as a possible risk factor for injury to the anterior cruciate ligament (ACL) and has also been shown to be associated with ACL reconstruction graft failure. It is currently unknown whether increased posterior tibial slope is an additional risk factor for further injury in the context of revision ACL reconstruction.

Purpose:

To determine the relationship between posterior tibial slope and further ACL injury in patients who have already undergone revision ACL reconstruction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 330 eligible patients who had undergone revision ACL reconstruction between January 2007 and December 2015 were identified from a clinical database. The slope of the medial and lateral tibial plateaus was measured on perioperative lateral radiographs by 2 fellowship-trained orthopaedic surgeons using a digital software application. The number of subsequent ACL injuries (graft rupture or a contralateral injury to the native ACL) was determined at a minimum follow-up of 2 years (range, 2-8 years). Tibial slope measurements were compared between patients who sustained further ACL injury to either knee and those who did not.

Results:

There were 50 patients who sustained a third ACL injury: 24 of these injuries were to the knee that underwent revision ACL reconstruction, and 26 were to the contralateral knee. Medial and lateral slope values were significantly greater for the third-injury group compared with the no–third injury group (medial, 7.5° vs 6.3° [P = .01]; lateral, 13.6° vs 11.9° [P = .001]).

Conclusion:

Increased posterior tibial slope, as measured from lateral knee radiographs, was associated with increased risk of graft rupture and contralateral ACL injury after revision ACL reconstruction. This is consistent with the concept that increased posterior slope, particularly of the lateral tibial plateau, is an important risk factor for recurrent ACL injury.

Complications After Pediatric ACL Reconstruction: A Meta-analysis

BACKGROUND

The purpose of this meta-analysis is to review clinical outcomes and complications following pediatric anterior cruciate ligament (ACL) reconstruction.

METHODS

The PubMed and EMBASE databases were searched for studies on ACL ruptures in the skeletally immature from 1985 to 2016. Full-text studies in English and performed on humans were included (n=5718). Titles included discussed operative intervention on skeletally immature patients with ACL tears (n=160). Studies that reported rerupture and/or complications with ACL reconstruction specific to the pediatric population, specifically growth disturbance, were then included in a secondary analysis (n=45). Complications not specific to the pediatric population were excluded. Demographics, graft type, surgical technique, follow-up, growth disturbance, rerupture, and patient-reported outcome scores were collected. Data were analyzed in aggregate.

RESULTS

In total, 45 studies were included with 1321 patients and 1392 knees. The average age was 13.0 years, 67% were male, and mean follow-up was 49.6 months. There were 115 (8.7%) reruptures in the initial 160 studies reviewed. In total, 94.6% of patients with rerupture required revision ACL surgery. There were 58 total growth disturbances (16 required corrective surgery, or 27.6%). Eighteen knees (3.7%) developed angular deformity, most commonly valgus. There were 37 patients (7.5%) had at least a 1 cm limb-length discrepancy. A total of 23 studies reported International Knee Documentation Committee scores (range, 81 to 100, 88% grade A or B). In total, 20 studies reported excellent Lysholm scores with mean scores of 94.6.

CONCLUSIONS

Growth disturbance can occur with any of the reconstruction techniques. Proper surgical technique is likely more important than the specific reconstruction technique utilized. Patients with rerupture require surgery at much higher rates than those with growth disturbance. Although much attention has been focused on growth disturbance, we suggest that equal attention be given to the prevention of rerupture in this age group.

LEVEL OF EVIDENCE

Level III.

Allograft tendons are a safe and effective option for revision ACL reconstruction: a clinical review

Revision anterior cruciate ligament reconstruction remains a challenge, especially optimising outcome for patients with a compromised knee where previous autogenous tissue has been used for reconstruction. Allograft tissue has become a recognized choice of graft for revision surgery but questions remain over the risks and benefits of such an option. Allograft tendons are a safe and effective option for revision ACL reconstruction with no higher risk of infection and equivalent failure rates compared to autografts provided that the tissue is not irradiated, or any irradiation is minimal. Best scenarios for use of allografts include revision surgery where further use of autografts could lead to high donor site morbidity, complex instability situations where additional structures may need reconstruction, and in those with clinical and radiologic signs of autologous tendon degeneration. A surgeon needs to be able to select the best option for the challenging knee facing revision ACL reconstruction, and in the light of current data, allograft tissue can be considered a suitable option to this purpose.Level of evidence IV.

Comparison of Knee Stability, Strength Deficits, and Functional Score in Primary and Revision Anterior Cruciate Ligament Reconstructed Knees

Comparing to primary surgery, revision ACL reconstruction is more technically demanding and has a higher failure rate. Theoretically, rehabilitation can improve knee function after ACL reconstruction surgery. This study aimed to compare knee stability, strength, and function between primary and revision ACL reconstructed knees. 40 primary and 40 revision ACL reconstruction surgeries were included between April 2013 and May 2016. Patients with revision surgery had a higher anteroposterior translation comparing those with primary reconstruction (median laxity, 2.0 mm vs. 3.0 mm, p = 0.0022). No differences were noted in knee extensor at 60°/sec or 180°/sec (p = 0.308, p = 0.931, respectively) or in flexor muscle strength at 60°/sec or 180°/sec between primary and revision ACL reconstruction knees (p = 0.091, p = 0.343, respectively). There were also no significant differences between functional scores including IKDC score and Lysholm score in primary versus revision surgeries at 12th months after index operation (p = 0.154, p = 0.324, respectively). In conclusion, despite having higher anteroposterior instability, patients with revision ACL reconstruction can have non-inferior outcomes in isokinetic knee strength and function compared to those with primary ACL reconstruction after proper rehabilitation.

CONTRALATERAL PATELLAR TENDON AUTOGRAFT IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

OBJECTIVE

To conduct a systematic review of literature about the use of contralateral patellar tendon autograft in anterior cruciate ligament reconstructions and present the results.

METHODS

The LILACS, MEDLINE, Cochrane, PubMed, Scielo and Google Scholar databases were searched without date restrictions for the keywords "anterior cruciate ligament reconstruction" combined with "contralateral" in the article title. After the studies were identified, two independent evaluators collected the qualitative characteristics of the studies and classified them according to clinical outcomes of these grafts as positive, neutral, or negative.

RESULTS

A total of 755 articles were found initially, and after detailed evaluation of all references, followed by a screening process and assessment of quality, a total of 11 studies were determined to be eligible for inclusion in this systematic review. Of these, 72.72% were level II studies, the most common level of evidence among the results. Positive results for this type of graft were found in 63.63% of the studies.

CONCLUSION

Based on the literature review, most of the included articles (63.63%) presented positive results for the use of contralateral patellar tendon grafts. Level of Evidence III; Systematic review.

Generalized Hypermobility, Knee Hyperextension, and Outcomes After Anterior Cruciate Ligament Reconstruction: Prospective, Case-Control Study With Mean 6 Years Follow-up

PURPOSE

To determine whether generalized hypermobility and contralateral knee hyperextension affect failure rates and patient-related outcomes after anterior cruciate ligament reconstruction (ACLR).

METHODS

A total of 226 consecutive patients presenting with acute ACL tears were prospectively evaluated for generalized hypermobility by a modified Beighton criteria. Minimum 2-year follow-up was achieved for 183 knees (81%). Patients underwent ACLR with either bone-patellar-tendon (BPTB) autograft (n = 46), quadrupled hamstring (HT) autograft (n = 85), or allograft tissue (n = 52). KT-1000 measurements, International Knee Documentation Committee (IKDC), Cincinnati, and Lysholm scores were obtained.

RESULTS

Forty-one of 183 consecutive patients were categorized as hypermobile. At mean 6 years' follow-up (range 2-12.5 years), IKDC (P = .003), Cincinnati (P = .001), and Lysholm scores (P < .001) were significantly better in the Non-Hypermobile group for patients with an intact graft. The failure rate was higher in the Hypermobile group (10 knees, 24.4% failure rate) compared with the Nonhypermobile group (11 knees, 7.7% failure rate) (P = .006). The overall ACL injury rate (ACL graft injury, excessive graft laxity, plus contralateral ACL tear) was higher in the Hypermobile group (34.1%) compared with the Nonhypermobile group (12.0%) (P = .002). Heel height >5 cm (P = .009) and fifth metacarpophalangeal (MCP) extension >90° (P = .006) were independently predictive of failure for the entire study population.

CONCLUSIONS

Graft failure rates were higher and inferior subjective outcomes were observed after ACLR in patients with generalized hypermobility. Heel height and fifth MCP hyperextension were most predictive of ACL injury/reinjury and poorer outcome scores. Nearly one-third of hypermobile patients sustained a contralateral ACL tear, ipsilateral graft failure, or had excessive graft laxity.

LEVEL OF EVIDENCE

Level III, case control study.

Anterior Cruciate Ligament Revision Surgery: Ipsilateral Quadriceps Versus Contralateral Semitendinosus-Gracilis Autografts

PURPOSE

To evaluate the subjective outcomes, knee stability, and donor-site morbidity after revision ACL reconstruction using either autologous ipsilateral quadriceps tendon or contralateral semitendinosus-gracilis tendon.

METHODS

A sample size calculation suggested that we needed 25 patients in each group to detect equality between both groups. Therefore, we evaluated 30 consecutive patients who underwent an ACL revision surgery with ipsilateral bone-quadriceps tendon grafts and 30 consecutive patients with the contralateral semitendinosus-gracilis grafts between January 2010 and December 2012. Because of follow-up and exclusion criteria, finally 51 patients were evaluated. All patients were followed prospectively for at least 2 years with KT1000 arthrometer testing and the International Knee Documentation Committee (IKDC) objective grading. At the 24-month follow-up, additional clinical scores were evaluated: the Knee Injury Osteoarthritis Outcome Score (KOOS), the Lysholm score, assessing pain during kneeling, and anterior knee pain.

RESULTS

The KT1000 postoperative arthrometer side-to-side difference was 2.0 ± 1.2 mm for the quadriceps group and 3.0 ± 2.9 mm for the semitendinosus-gracilis group. The difference was not statistically significant (P = .461). There was also no difference in the rate of positive pivot-shift tests between groups (P = .661). The Lysholm score was 82.5 ± 18 in the quadriceps group and 73.8 ± 19 in the semitendinosus-gracilis group. The difference was not statistically significant (P = .060). There was also no significant difference in the single KOOS subscores, assessing pain while kneeling and anterior knee pain (included in the KOOS score). No rerupture occurred during follow-up.

CONCLUSIONS

Revision ACL reconstruction using the quadriceps tendon graft showed clinical outcomes similar to those of the contralateral semitendinosus-gracilis graft in terms of knee stability and function. Thus, the bone-quadriceps tendon graft may be a good alternative to the contralateral semitendinosus-gracilis tendon graft for revision ACL reconstruction.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Single-Bundle Anatomic Anterior Cruciate Ligament Reconstruction: Surgical Technique Pearls and Pitfalls

Anterior cruciate ligament (ACL) ruptures are some of the most common sports-related injuries. Treatment of these injuries with ACL reconstruction has evolved over the last several decades. Anatomic single-bundle ACL reconstruction offers an accurate and reproducible method to reproduce native knee anatomy, restore knee kinematics, and ultimately restore function and decrease long-term degenerative effects. The importance of adequate arthroscopic visualization and a thorough understanding of the native anatomic ACL landmarks are discussed in this article. Furthermore, surgical technique, pearls, pitfalls, potential complications, rehabilitation, and outcomes are reviewed.

Healing of tibial bone tunnels after bone grafting for staged revision anterior cruciate ligament surgery: A prospective computed tomography analysis

AIM

To quantify healing of tibial bone tunnels after bone grafting in two-stage ACL reconstruction revision.

METHODS

Ten consecutive patients underwent autogenous bone grafting prior to ACL reconstruction revision (four females and six males, average age 28years). The indications for two-stage surgery were as follows: (1) the enlargement of the tibial tunnel aperture was >20mm in diameter or, (2) the existing tunnel was overlapped with the optimal tunnel and positioned more than a half tunnel diameter posterior to the optimal position. An autogenous iliac bone block was driven into a new tunnel. CT examinations were performed at three, 12 and 24weeks after bone grafting. Evaluations were performed on 15 axial planes at one-millimeter intervals from the articular surface perpendicular to the long axis of the tibia using the following three parameters: occupying ratio (OR), union ratio (UR), and bone mineral density (BMD) of grafted bone.

RESULTS

The average ORs were 81, 85 and 94%, and the average URs were 49, 75 and 89% at three, 12 and 24weeks, respectively. Each parameter significantly increased over time. The average BMD was 510 and 571mg/cm(3) at 12 and 24weeks, respectively, with a significantly higher value at 24weeks.

CONCLUSION

The average ORs, URs and BMD at 24weeks after bone grafting were higher than those at 12weeks, which suggests that at 24weeks after bone grating, the condition of the patients' beds becomes favorable for safe implantation and fixation of ACL graft revision.

LEVEL OF EVIDENCE

Case series Level IV.

The Development and Early to Midterm Findings of the Multicenter Revision Anterior Cruciate Ligament Study

Revision anterior cruciate ligament (ACL) reconstruction can present a series of unique challenges for the both the patient and the treating surgeon. The Multicenter ACL Revision Study (MARS) was established to identify the factors contributing to ACL graft failure and report on the outcomes following revision reconstruction. In this article we review the development and early to midterm findings of the MARS group.

Reliability of 3-Dimensional Computed Tomography for Application of the Bernard Quadrant Method in Femoral Tunnel Position Evaluation After Anatomic Anterior Cruciate Ligament Reconstruction

PURPOSE

To validate whether the Bernard quadrant method, which was developed for application on simple lateral radiography, can be used with 3-dimensional computed tomography (3D CT) to localize the femoral insertion of the reconstructed anterior cruciate ligament (ACL).

METHODS

We analyzed 32 knees with ACL tears that were reconstructed using a metal interference screw for fixation at the femoral tunnel between March 2012 and May 2013. Postoperative lateral radiographs and 3D CT images were obtained 7 days after the operation. By use of the Bernard quadrant method, the location of the femoral tunnel was measured by 2 orthopaedic surgeons by locating the position of the metal interference screw using 3D CT imaging and simple lateral knee radiography. The correlation between the femoral tunnels on the 2 radiographic images was compared using the MedCalc statistical analysis program.

RESULTS

On the 3D CT image, the position of the femoral insertion of the ACL as measured by the position of the metal screw head was 36.3% ± 6.0% in the x-coordinate and 39.6% ± 9.1% in the y-coordinate compared with 37.6% ± 5.8% and 41.0% ± 11.6%, respectively, on the simple radiograph. The Pearson correlation coefficients between 3D CT and simple radiography were 0.840 for the x-coordinate and 0.858 for the y-coordinate. Intraobserver reliability and interobserver reliability for both coordinates were greater than 0.9 on 3D CT.

CONCLUSIONS

Application of the Bernard quadrant method on 3D CT showed high correlation to the originally described method using lateral radiographs and can be used reliably for localizing the reconstructed ACL.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Return-to-Sport Outcomes After Revision Anterior Cruciate Ligament Reconstruction Surgery

BACKGROUND

There are limited and inconsistent data regarding return-to-sport outcomes after revision anterior cruciate ligament reconstruction (ACLR).

HYPOTHESIS

Return-to-sport rates will be lower after revision ACLR when compared with primary ACLR.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The study cohort consisted of 136 eligible patients who had undergone their first revision ACLR between March 2006 and March 2010. Of these, 109 patients (80%) completed a sports activity survey at a mean 5-year follow-up (range, 3-7 years). Follow-up also included the International Knee Documentation Committee (IKDC) subjective form, Marx Activity Scale, and Knee injury and Osteoarthritis Outcome Score-quality of life (KOOS-QOL) form. Operative details were obtained from the clinical record.

RESULTS

After revision ACLR, 46% (95% CI, 37%-55%) of patients returned to their preinjury level of sport, compared with 50% (95% CI, 41%-59%) after the primary reconstruction in the same patients. Of the patients who were not able to return to their preinjury level of sport after primary reconstruction, 33% improved to the point that they were able to do so after revision. Younger patients were more likely to have returned to their same level of sport (58% vs 38%, P < .05), while the rate of return was the same between male and female patients. Those who returned to their preinjury level of sport scored higher Marx (P < .01), KOOS-QOL (P < .001), and IKDC scores (P < .01) than those who did not. Patients with <50% thickness articular cartilage lesions at revision surgery were more likely to have returned to their preinjury level (52% vs 31%, P < .05) and had significantly better Marx (P < .01), KOOS-QOL (P < .01), and IKDC scores (P < .01) at follow-up. The status of the menisci at the time of revision surgery was not associated with rates of return to sport, but patients with an intact medial meniscus had significantly higher KOOS-QOL (P < .05) scores at follow-up.

CONCLUSION

Return-to-sport rates of patients after revision ACLR were similar to those after their primary surgery but were still lower than the reported rates of ACLR patients who did not need revision surgery. Greater chondral pathologic abnormalities at revision surgery were associated with reduced function at follow-up.

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.

Patient demographics and surgical characteristics in ACL revision: a comparison of French, Norwegian, and North American cohorts

PURPOSE

The goal of this paper is to compare patient factors, intra-operative findings, and surgical techniques between patients followed in large cohorts in France, Norway, and North America.

METHODS

Data collected on 2,286 patients undergoing revision anterior cruciate ligament reconstruction (ACLR) were obtained. These data included 1,216 patients enrolled in the Multicenter ACL Revision Study (MARS) in North America, 793 patients undergoing revision ACLR and recorded in the Norwegian Knee Ligament Registry (NKLR), and 277 patients recorded in the revision ACL database of the Société Française d'Arthroscopie (SFA) in France. Data collected from each database included patient demographics (age, sex, height, and weight), graft choice and reason for failure of the primary ACLR, time from primary to revision ACLR, pre-revision patient-reported outcome scores (Knee Injury and Osteoarthritis Outcome Score, subjective International Knee Documentation Committee), associated intra-articular findings and treatments at revision, and graft choice for revision reconstruction.

RESULTS

Patient demographics in the three databases were relatively similar. Graft choice for primary and revision ACLR varied significantly, with more allografts used in the MARS cohort. Hamstring autograft was favoured in the NKRL, while bone-patellar tendon-bone autograft was most common in the SFA cohort. Reasons for failure of the primary ACLR were comparable, with recurrent trauma noted in 46-56 % of patients in each of the three cohorts. Technical error was cited in 44-51 % of patients in the MARS and SFA cohorts, but was not clearly elucidated in the NKLR cohort. Biologic failure of the primary graft was more common in the MARS cohort. Differences in associated intra-articular findings were noted at the time of revision ACLR, with significantly more high-grade cartilage lesions noted in the MARS group.

CONCLUSIONS

Significant differences exist between patient populations followed in revision ACL cohorts throughout the world that should be considered when applying findings from such cohorts to different patient populations.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Radiographic Anatomy of the Native Anterior Cruciate Ligament: a Systematic Review

BACKGROUND

In an attempt to improve the accuracy and reproducibility of tunnel positioning, radiographs are being analyzed in an attempt to recreate the native anatomy of the ACL. Understanding the native ACL radiographic anatomy is an essential prerequisite to understand the relevance of postoperative tunnel position.

QUESTIONS/PURPOSES

We performed a systematic review of the literature to delineate the radiographic location of the native ACL femoral and tibial footprints.

METHODS

A search was performed in March 2014 in PubMed, the Cochrane Collaboration Library, and EMBASE to identify all studies that evaluated the native anterior cruciate ligament (ACL) anatomy on radiographs. Various measurement methods were used in each study, and averages were obtained of the data from studies with the same measurement methods.

RESULTS

Fifteen papers were identified (which included data on 177 femora and 207 tibiae in total). Evaluation of the femoral footprint using the quadrant method on lateral knee radiographs showed that the average percent distance location of the anteromedial (AM) bundle and posterolateral (PL) bundle was 22.8% (95% confidence interval (CI) 16.59-28.90) and 32.5% (95% CI 27.71-37.26) from the posterior condyle, respectively, and 23.2% (95% CI 19.52-26.94) and 50.0% (95% CI 46.16-53.76) from Blumensaat's line, respectively. Using the Amis and Jacob method, the tibial footprint on the lateral knee radiograph average percent distances was 35.1% (95% CI 34.46-35.72) for the center of the AM bundle and 47.3% (95% CI 41.69-52.95) for the center of the PL bundle of the ACL. The femoral and tibial ACL footprints on the anteroposterior (AP) views of the knee were not well delineated by these studies.

CONCLUSION

The information presented in this systematic review offers surgeons another important tool for accurate ACL footprint identification.

The effect of graft strength on knee laxity and graft in-situ forces after posterior cruciate ligament reconstruction

Surgical reconstruction is generally recommended for posterior cruciate ligament (PCL) injuries; however, the use of grafts is still a controversial problem. In this study, a three-dimensional finite element model of the human tibiofemoral joint with articular cartilage layers, menisci, and four main ligaments was constructed to investigate the effects of graft strengths on knee kinematics and in-situ forces of PCL grafts. Nine different graft strengths with stiffness ranging from 0% (PCL rupture) to 200%, in increments of 25%, of an intact PCL's strength were used to simulate the PCL reconstruction. A 100 N posterior tibial drawer load was applied to the knee joint at full extension. Results revealed that the maximum posterior translation of the PCL rupture model (0% stiffness) was 6.77 mm in the medial compartment, which resulted in tibial internal rotation of about 3.01°. After PCL reconstruction with any graft strength, the laxity of the medial tibial compartment was noticeably improved. Tibial translation and rotation were similar to the intact knee after PCL reconstruction with graft strengths ranging from 75% to 125% of an intact PCL. When the graft's strength surpassed 150%, the medial tibia moved forward and external tibial rotation greatly increased. The in-situ forces generated in the PCL grafts ranged from 13.15 N to 75.82 N, depending on the stiffness. In conclusion, the strength of PCL grafts have has a noticeable effect on anterior-posterior translation of the medial tibial compartment and its in-situ force. Similar kinematic response may happen in the models when the PCL graft's strength lies between 75% and 125% of an intact PCL.

Revision anterior cruciate ligament reconstruction

Context:

Reconstruction of the anterior cruciate ligament (ACL) is one of the most common surgical procedures, with more than 200,000 ACL tears occurring annually. Although primary ACL reconstruction is a successful operation, success rates still range from 75% to 97%. Consequently, several thousand revision ACL reconstructions are performed annually and are unfortunately associated with inferior clinical outcomes when compared with primary reconstructions.

Evidence Acquisition:

Data were obtained from peer-reviewed literature through a search of the PubMed database (1988-2013) as well as from textbook chapters and surgical technique papers.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

The clinical outcomes after revision ACL reconstruction are largely based on level IV case series. Much of the existing literature is heterogenous with regard to patient populations, primary and revision surgical techniques, concomitant ligamentous injuries, and additional procedures performed at the time of the revision, which limits generalizability. Nevertheless, there is a general consensus that the outcomes for revision ACL reconstruction are inferior to primary reconstruction.

Conclusion:

Excellent results can be achieved with regard to graft stability, return to play, and functional knee instability but are generally inferior to primary ACL reconstruction. A staged approach with autograft reconstruction is recommended in any circumstance in which a single-stage approach results in suboptimal graft selection, tunnel position, graft fixation, or biological milieu for tendon-bone healing.

Strength-of-Recommendation Taxonomy (SORT):

Good results may still be achieved with regard to graft stability, return to play, and functional knee instability, but results are generally inferior to primary ACL reconstruction: Level B.

Proximal Tibial Anterior Closing Wedge Osteotomy in Repeat Revision of Anterior Cruciate Ligament Reconstruction

BACKGROUND

Physicians should consider an increased posterior tibial slope (PTS) as a risk factor for graft failure when proposing anterior cruciate ligament (ACL) re-revision.

PURPOSE

To describe the surgical technique of combined ACL revision and proximal tibial anterior closing wedge osteotomy and to evaluate its clinical outcome in cases of recurrent graft failure with associated increased tibial slope.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 2008 and 2010, 5 combined ACL re-revisions with proximal tibial anterior closing wedge osteotomy were retrospectively evaluated after a mean 31.6 months' follow-up (range, 23-45 months). All patients reported subjective knee instability preoperatively and demonstrated increased laxity on physical examination. Intrinsic risk factors for graft failure (excessive tibial slope) were identified in all cases. Preoperative and postoperative functional assessments included the International Knee Documentation Committee (IKDC) score along with the Lysholm score and Tegner activity scale.

RESULTS

The mean Lysholm score was 46.2 preoperatively (range, 26-69) and 87.8 (range, 60-100) postoperatively. The mean IKDC subjective score was 39.5 (range, 21.8-64.4) before surgery and 79.1 (range, 48.3-98.9) at the last follow-up. The mean Tegner activity score was 7.4 (range, 5-9) before the latest ACL injury and 7.2 (range, 5-9) at the last follow-up. The mean PTS was 13.6° (range, 13°-14°) preoperatively and 9.2° (range, 8°-10°) postoperatively (P = .0005). The mean differential anterior laxity was 10.4 mm (range, 8-14 mm), and this significantly decreased to 2.8 mm (range, 2-4 mm) at the last follow-up. Using the Kellgren-Lawrence classification to evaluate the presence of arthritis, 1 patient was grade 1, 3 patients were grade 2, and 1 patient was grade 3.

CONCLUSION

Combined ACL re-revision with proximal tibial anterior closing wedge osteotomy restores knee stability and function with satisfactory clinical outcomes in patients who experience recurrent ACL ruptures with an associated increased PTS.

Avoiding Complications and Technical Variability During Arthroscopically Assisted Transtibial ACL Reconstructions by Using a C-Arm With Image Intensifier

BACKGROUND

Surgical reconstruction of the anterior cruciate ligament (ACL) can be complicated by incorrect and variable tunnel placement, graft tunnel mismatch, cortical breaches, and inadequate fixation due to screw divergence. This is the first report describing the use of a C-arm with image intensifier employed for the sole purpose of eliminating those complications during transtibial ACL reconstruction.

PURPOSE

To determine if the use of a C-arm with image intensifier during arthroscopically assisted transtibial ACL reconstruction (IIAA-TACLR) eliminated common complications associated with bone-patellar tendon-bone ACL reconstruction, including screw divergence, cortical breaches, graft-tunnel mismatch, and improper positioning of the femoral and tibial tunnels.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 110 consecutive patients (112 reconstructed knees) underwent identical IIAA-TACLR using a bone-patellar tendon-bone autograft performed by a single surgeon. Intra- and postoperative radiographic images and operative reports were evaluated for each patient looking for evidence of cortical breeching and screw divergence. Precision of femoral tunnel placement was evaluated using a sector map modified from Bernard et al. Graft recession distance and tibial α angles were recorded.

RESULTS

There were no femoral or tibial cortical breaches noted intraoperatively or on postoperative images. There were no instances of loss of fixation screw major thread engagement. There were no instances of graft-tunnel mismatch. The positions of the femoral tunnels were accurate and precise, falling into the desired sector of our location map (sector 1). Tibial α angles and graft recession distances varied widely.

CONCLUSION

The use of the C-arm with image intensifier enabled accurate and precise tunnel placement and completely eliminated cortical breach, graft-tunnel mismatch, and screw divergence during IIAA-TACLR by allowing incremental adjustment of the tibial tunnel and knee flexion angle. Incremental adjustment was essential to accomplish this. Importantly, a C-arm with image intensifier can be used with any ACL reconstruction that incorporates tunnels in the technique, with the expectation of increase in accuracy and precision and the elimination of common complications.

CLINICAL RELEVANCE

The use of an image intensifier during transtibial ACL reconstruction will substantially reduce the common complications associated with the procedure and improve both accuracy and precision of tibial and femoral tunnel placement. Use of an image intensifier unit is generalizable to an individual surgeon's preferences for graft choices and drilling techniques and will be especially valuable when the intercondylar architecture is altered from injury, time, or prior surgery.

Use of a fluoroscopic overlay to assist arthroscopic anterior cruciate ligament reconstruction

BACKGROUND

A growing body of evidence supports the importance of anatomic tunnel positioning in the success of anterior cruciate ligament (ACL) reconstruction, which stimulates the need for technologies to aid surgeons in achieving accurate anatomic tunnel placement. Intraoperative fluoroscopy is potentially one such technology, while its efficacy and usability have yet to be established.

PURPOSE

To investigate the performance of an intraoperative fluoroscopic overlay in guiding tunnel placement during ACL reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty cadaveric knees underwent computed tomography (CT) scans and arthroscopic digitization of ACL insertion sites. The outlines of the digitized insertion sites were mapped to the corresponding CT-acquired bone models through a co-registration procedure. Twenty orthopaedic surgeons performed simulated ACL reconstructions, each on a randomly assigned cadaveric knee, first without and then with the aid of a fluoroscopic overlay system. The overlay system displayed on a lateral fluoroscopic image targets points representing the locations of the ACL insertion sites estimated from the literature data. Surgeons were allowed to adjust their tunnel positions under the guidance of the fluoroscopic image. Their initial, intermediate, and final positions were documented and compared with the target points as well as the native insertion sites.

RESULTS

Surgeons demonstrated significant (P < .01) improvements in femoral and tibial tunnel placements relative to the target points from an average distance of 3.9 mm to 1.6 mm on the femur and 2.1 mm to 0.9 mm on the tibia. The improvements toward the knee-specific actual insertion sites were significant on the tibial side but not on the femoral side.

CONCLUSION

Surgeons can be successfully guided with fluoroscopy to create more consistent femoral and tibial tunnels during ACL reconstruction. More research is warranted to develop better population representations of the locations of natural insertion sites.

CLINICAL RELEVANCE

Intraoperative fluoroscopy can be an effective, easy, and safe method for improving tunnel positioning during ACL reconstruction.

Allograft salvage procedure in multiple-revision anterior cruciate ligament reconstruction

BACKGROUND

Multiple-revision anterior cruciate ligament (ACL) reconstructions represent a surgical challenge due to the presence of previous tunnels, hardware, injuries to the secondary stabilizers, and difficulties in retrieving autologous tendons. An anatomic ACL reconstruction may therefore result in a demanding surgery, thus requiring 2 stages.

PURPOSE

To analyze the efficacy of an over-the-top ACL reconstruction technique plus extra-articular plasty using Achilles or tibialis posterior tendon allograft in restoring knee stability in patients with at least 2 failed previous ACL reconstructions, as well as to evaluate the factors able to affect the final outcome.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From 2002 to 2008, 24 male athletes with a mean age of 30.8 years underwent surgery. Twenty patients had undergone 2, whereas 4 patients had undergone 3 previous reconstructions. The International Knee Documentation Committee (IKDC) score and KT-2000 arthrometric evaluation were used to measure outcomes at a mean follow-up period of 3.3 years (range, 2-7).

RESULTS

The mean ± SD IKDC subjective score at follow-up was 81.3 ± 14.0. The IKDC objective score was an A or B in 20 patients (83%). Arthrometer side-to-side difference averaged 3.1 ± 1.1 mm. Range of motion was normal or nearly normal in 23 patients and abnormal in 1. Of the 20 good results, 17 patients resumed sports activity at the preinjury level.

CONCLUSION

A 2-stage revision is an accepted option in cases of excessive tunnel enlargement and bone loss, especially on the femoral side, to achieve anatomic reconstruction. Nonanatomic over-the-top ACL reconstruction and lateral extra-articular plasty technique allow one to overcome difficult anatomic situations on the femoral side, permitting a 1-step surgery. The overall results obtained in this series are comparable with those of other ACL revision series. The higher rate of mild instability observed in our series may not be attributable to the surgical technique but rather to the chronic instability suffered by these knees before last revision.

Femoral tunnel malposition in ACL revision reconstruction

The Multicenter Anterior Cruciate Ligament (ACL) Revision Study (MARS) group was formed to study a large cohort of revision ACL reconstruction patients. The purpose of this subset analysis study of the MARS database is to describe specific details of femoral tunnel malposition and subsequent management strategies that surgeons chose in the revision setting. The design of this study is a case series. The multicenter MARS database is compiled from a questionnaire regarding 460 ACL reconstruction revision cases returned by 87 surgeons. This subset analysis described technical aspects and operative findings in specifically those cases in which femoral tunnel malposition was cited as the cause of primary ACL reconstruction failure. Of the 460 revisions included for study, 276 (60%) cases cited a specific "technical cause of failure." Femoral tunnel malposition was cited in 219 (47.6%) of 460 cases. Femoral tunnel malposition was cited as the only cause of failure in 117 cases (25.4%). Surgeons judged the femoral tunnel too vertical in 42 cases (35.9%), too anterior in 35 cases (29.9%), and too vertical and anterior in 31 cases (26.5%). Revision reconstruction involved the drilling of an entirely new femoral tunnel in 91 cases (82.1%). For primary reconstruction, autograft tissue was used in 82 cases (70.1%). For revision reconstruction, autograft tissue was used in 61 cases (52.1%) and allograft tissue in 56 cases (47.9%). Femoral tunnel malposition in primary ACL reconstruction was the most commonly cited reason for graft failure in this cohort. Graft selection is widely variable among surgeons.

Reliability of tunnel measurements and the quadrant method using fluoroscopic radiographs after anterior cruciate ligament reconstruction

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction tunnel placement is often evaluated by radiographs. This study examines the interobserver reliability of various radiographic measurements of ACL tunnels.

HYPOTHESIS

When ideal radiographic views are obtained, the interobserver reliability of the measurements among experienced surgeons would be good to excellent.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Tunnels for single-bundle ACL reconstruction were drilled and filled with metal interference screws or a tibial reamer on 73 cadaveric knees. Ideal fluoroscopic radiographs were obtained. Three independent reviewers performed 18 measurements including a modification of the grid method. For the grid method analysis, reviewers fit a 16 × 12 grid to the lateral knee radiograph, and the center of the femoral tunnel was marked. Interobserver reliability of the measurements was performed using intraclass correlation coefficients (ICCs). A precision grouping analysis was performed for the grid measurements to calculate the mean radius and standard deviation grouping distances.

RESULTS

The ICCs were excellent (>.75) for the tibial tunnel angles and tunnel measurements, the clock face measurement, and the Aglietti et al and Jonsson et al measurements. The ICCs were good (.4-.75) for an estimation of graft impingement, Harner et al measurements, and notch height. The mean radius for grid measurements was 0.6 ± 0.4 units (range, 0-2.36 units), with each unit being 1 box in the 16 × 12 grid. When a circle was constructed with a 1.3-unit radius, 95% of the 3 surgeons' measurements would be included in the area of that circle.

CONCLUSION

Reliability of ACL tunnel measurements was good to excellent under ideal circumstances for the majority of measurements. The modified grid method demonstrated very acceptable reliability.

CLINICAL RELEVANCE

Measurements with good to excellent reliability can be used to evaluate ACL tunnel placement when ideal radiographic views are obtained.

Revision anterior cruciate ligament reconstruction: an update

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

Revision ACL reconstruction: influence of a lateral tenodesis

PURPOSE

The aims of this article were to report the objective results of revision ACL reconstruction and to assess the influence of an associated lateral extra-articular tenodesis on knee stability and IKDC score.

METHODS

This study focused on revision ACL reconstruction and was conducted over a 10-year period, from 1994 to 2003 with ten French orthopedic centers participating. The minimum follow-up required was 2 years. To be included, patients had to be evaluated at follow-up with the objective International Knee Documenting Committee (IKDC) scoring system. In 2006, 163 patients met the inclusion criteria.

RESULTS

The objective IKDC knee score improved significantly after revision ACL reconstruction, with 72% IKDC A + B (26% A). When a lateral tenodesis was performed, 80% had a negative pivot shift, versus 63% without (P = 0.03), but there was no significant difference in the IKDC score.

CONCLUSION

This study shows a significant improvement in the IKDC score after revision ACL reconstruction. The association of a lateral extra-articular tenodesis with the intra-articular graft increases knee stability after revision ACL reconstruction; however, this additional procedure does not significantly alter the IKDC score at follow-up.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

Over-the-top double-bundle revision ACL reconstruction

Revision ACL presents many technical issues that are not seen in the primary ACL reconstruction. A variety of surgical techniques for revising ACL reconstruction have been described in the literature to address these concerns. The purpose of this article is to present a novel technique consisting in a non-anatomic double-bundle ACL revision reconstruction, using a fresh-frozen Achilles tendon allograft with soft tissue fixation. This technique is a valid treatment option when faced with a complex scenario such as ACL revision surgery.

Reliability of early postoperative radiographic assessment of tunnel placement after anterior cruciate ligament reconstruction

PURPOSE

To evaluate the interobserver and intraobserver reliability of radiographic assessment of tunnel placement in anterior cruciate ligament reconstruction.

METHODS

Seven sports fellowship-trained orthopaedic surgeons in the Multicenter Orthopaedic Outcomes Network (MOON) group participated in the study. We prospectively enrolled 54 consecutive patients after primary anterior cruciate ligament reconstruction. Postoperative plain radiographs were obtained including a full-extension anteroposterior view of the knee, a lateral view of the knee in full extension, and a notch view at 45° of flexion (Rosenberg view). Three blinded reviewers performed 8 different radiographic measurements including those of Harner and Aglietti/Jonsson. Intraclass correlation coefficients were used to determine reliability of the measurements. Intrarater reliability was assessed by repeated measurements of a subset of 20 patient images from 1 institution, and inter-rater reliability was assessed by use of all 54 sets of films from a total of 4 institutions.

RESULTS

Intraobserver reliability for femoral measures ranged from none to substantial, with notch height having the worst results. Intraobserver reliability was moderate to almost perfect for tibial measures. Interobserver reliability ranged from slight to moderate for femoral measures. The Harner method for determining tunnel depth was more reliable than the Aglietti/Jonsson method. Interobserver reliability for tibial measures ranged from fair to substantial. The presence of metal interference screws did not improve reliability of measurements.

CONCLUSIONS

Postoperative radiographs are easily obtained, but our results show that radiographic measurements are of quite variable reliability, with most of the results falling into the fair to moderate categories.

A CT-based classification of prior ACL femoral tunnel location for planning revision ACL surgery

PURPOSE

The purposes of this study are to describe an ACL femoral tunnel classification system for use in planning revision ACL reconstruction based on 3-D computed tomography (CT) reconstructions and to evaluate its inter- and intra-rater reliability.

METHODS

A femoral tunnel classification system was developed based on the location of the femoral tunnel relative to the lateral intercondylar ridge. The femoral tunnel was classified as Type I if it was located entirely below and posterior to the ridge as viewed from distally, Type II if it was slightly malpositioned (either vertically, anteriorly, or both), and Type III if it was significantly malpositioned. To evaluate the reproducibility of the classification system, CT scans of 27 knees were obtained from patients scheduled for revision ACL reconstruction, and 3-D reconstructions were created. Four views of the 3-D reconstruction of each femur were then obtained, and inter- and intra-observer reliability was determined following classification of the tunnels by eight observers.

RESULTS

Twenty-five tunnels were classified as Type I (5 tunnels), Type II (9 tunnels), or type III (11 tunnels) by at least 5 of 8 observers, while insufficient agreement was noted to classify two tunnels. The interobserver reliability of tunnel classification as type I, II, or III yielded a κ coefficient of 0.57, while intra-observer reliability yielded a κ coefficient of 0.67. Subclassification of type II femoral tunnels into the subgroups anterior, vertical, and both was possible in four of the nine type II patients. The interobserver reliability of the complete classification system yielded a κ coefficient of 0.50, while the intra-observer reliability yielded a κ coefficient of 0.54.

CONCLUSION

Classification of the location of ACL femoral tunnels utilizing 3-D reconstructions of CT data yields moderate to substantial inter- and intra-observer reliability.

LEVEL OF EVIDENCE

Diagnostic Level III.

ACL graft failure location differs between allografts and autografts

BACKGROUND

Between 5 and 20% of patients undergoing ACL reconstruction fail and require revision. Animal studies have demonstrated slower incorporation of allograft tissue, which may affect the mechanism of graft failure. The purpose of this study is to determine the location of traumatic graft failure following ACL reconstruction and investigate differences in failure patterns between autografts and allografts.

METHODS

The medical records of 34 consecutive patients at our center undergoing revision ACL reconstruction following a documented traumatic re-injury were reviewed. Graft utilized in the primary reconstruction, time from initial reconstruction to re-injury, activity at re-injury, time to revision reconstruction, and location of ACL graft tear were recorded.

RESULTS

Median patient age at primary ACL reconstruction was 18.5 years (range, 13-39 years). The primary reconstructions included 20 autografts (13 hamstrings, 6 patellar tendons, 1 iliotibial band), 12 allografts (5 patellar tendon, 5 tibialis anterior tendons, 2 achilles tendons), and 2 unknown. The median time from primary reconstruction to re-injury was 1.2 years (range, 0.4 - 17.6 years). The median time from re-injury to revision reconstruction was 10.4 weeks (range, 1 to 241 weeks). Failure location could be determined in 30 patients. In the autograft group 14 of 19 grafts failed near their femoral attachment, while in the allograft group 2 of 11 grafts failed near their femoral attachment (p < 0.02).

CONCLUSIONS

When ACL autografts fail traumatically, they frequently fail near their femoral origin, while allograft reconstructions that fail are more likely to fail in other locations or stretch.

LEVEL OF EVIDENCE

Level III - Retrospective cohort study.

Outcome of revision anterior cruciate ligament reconstruction: a systematic review

BACKGROUND

Revision anterior cruciate ligament (ACL) reconstruction is believed to have an inferior outcome compared with primary ACL reconstruction. The available literature on the outcome of revision ACL reconstruction is sparse compared with that for primary reconstruction. The purpose of this systematic review was to test the hypothesis that the outcome of revision ACL reconstruction compares unfavorably with the historical outcome of primary ACL reconstruction.

METHODS

A systematic review of studies evaluating the outcome of revision ACL reconstructions with a minimum of two years of follow-up was performed. Pooled data were collected when appropriate and a mixed-effect-model meta-analysis was performed for important outcome measures that were reported in several studies (objective graft failure, Lysholm score, International Knee Documentation Committee [IKDC] subjective score, and IKDC objective score). Objective failure was defined as repeat revision, a side-to-side difference of &gt;5 mm measured with use of a KT1000 arthrometer, or a pivot-shift grade of 2+ or 3+.

RESULTS

Twenty-one studies were included, and 863 of the 1004 patients in these studies had a minimum of two years of follow-up and were analyzed. The pooled mean age of the patients at the time of the revision procedure was 30.6 years, and 66% were male. Objective failure occurred in 13.7% ± 2.7% of the patients (95% confidence interval, 8.0% to 19.4%). The mean Lysholm score in 491 patients was 82.1 ± 3.3 (95% confidence interval, 74.6 to 89.5) according to a mixed-model meta-analysis. The mean IKDC subjective score in 202 patients was 74.8 ± 4.4 (95% confidence interval, 62.5 to 87.0).

CONCLUSIONS

Revision ACL reconstruction resulted in a worse outcome compared with primary ACL reconstruction. Patient-reported outcome scores were inferior to previously published results of primary ACL reconstruction, but these differences may not be clinically important. A dramatically elevated failure rate was noted after revision ACL reconstruction; this rate was nearly three to four times the failure rate in prospective series of primary ACL reconstructions.

Quadriceps muscle activation and radiographic osteoarthritis following ACL revision

PURPOSE

Quadriceps strength and activation may play an important role in the recovery from ACL revision surgery. The purpose of this study was to describe quadriceps strength and central activation ratio (CAR) and correlate with radiographic findings in patients with ACL revision surgery.

METHODS

Twenty-one patients who were on average 47.5 ± 21.1 months [range: 14-85 months] post-revision ACL reconstruction. We performed knee joint physical examination and radiographic evaluation. Quadriceps strength testing consisted of maximal voluntary isometric contractions (MVIC) with the knee bent to 90-degrees bilaterally. We calculated quadriceps central activation ratio using the superimposed burst technique. Radiographs (bilateral standing antero-posterior in knee flexion and lateral in full extension) were evaluated by a fellowship-trained orthopedic surgeon using the International Knee Documentation Committee (IKDC) grading system.

RESULTS

Mean CAR was 83.9 ± 12.0% on the reconstructed limb and 85.5 ± 9.5% on the contralateral limb. Average, normalized MVIC torque was 2.5 ± 1.0 Nm/kg on the reconstructed limb and 2.7 ± 1.0 N m/kg for the contralateral limb. Patient age at the time of follow-up evaluation was related to severity of knee joint degeneration, particularly the medial, anterior and patellofemoral compartments. Younger patients with lower CARs tended to have more severe degeneration in the patellofemoral joint. Older patients with lower normalized MVIC torque values tended to exhibit more severely graded degeneration in the patellofemoral joint.

CONCLUSION

Bilateral quadriceps central activation deficits and radiographic osteoarthritis are evident in patients with revision ACL reconstruction.

Causes for failure of ACL reconstruction and influence of meniscectomies after revision

The purpose of this multicenter retrospective study was to analyze the causes for failure of ACL reconstruction and the influence of meniscectomies after revision. This study was conducted over a 12-year period, from 1994 to 2005 with ten French orthopaedic centers participating. Assessment included the objective International Knee Documenting Committee (IKDC) 2000 scoring system evaluation. Two hundred and ninety-three patients were available for statistics. Untreated laxity, femoral and tibial tunnel malposition, impingement, failure of fixation were assessed, new traumatism and infection were recorded. Meniscus surgery was evaluated before, during or after primary ACL reconstruction, and then during or after revision ACL surgery. The main cause for failure of ACL reconstruction was femoral tunnel malposition in 36% of the cases. Forty-four percent of the patients with an anterior femoral tunnel as a cause for failure of the primary surgery were IKDC A after revision versus 24% if the cause of failure was not the femoral tunnel (P = 0.05). A 70% meniscectomy rate was found in revision ACL reconstruction. Comparison between patients with a total meniscectomy (n = 56) and patients with preserved menisci (n = 65) revealed a better functional result and knee stability in the non-meniscectomized group (P = 0.04). This study shows that the anterior femoral tunnel malposition is the main cause for failure in ACL reconstruction. This reason for failure should be considered as a predictive factor of good result of revision ACL reconstruction. Total meniscectomy jeopardizes functional result and knee stability at follow-up.

Revision anterior cruciate ligament reconstruction

Revision reconstruction of the anterior cruciate ligament (ACL) introduces several diagnostic and technical challenges in comparison with primary ACL reconstruction. With the increasing numbers of original reconstructions combined with the continued expectation of high-level athletic participation, revision ACL reconstruction is likely to become more frequent. The purpose of this article was to summarize the causes of failure and the evaluation of the patient with recurrent instability. A review of the literature regarding results after revision ACL reconstruction was performed to assist in the decision-making process and patient counseling. Good results can be obtained in terms of functional stability after revision reconstruction, but chondral and meniscal injury as well as unrecognized associated pathologic instability may play a role in diminished outcomes. In addition, a wide variety of surgical techniques are reviewed to address problems associated with tunnel malposition, widening, and pre-existing hardware.

Cost-effectiveness of anterior cruciate ligament reconstruction: a preliminary comparison of single-bundle and double-bundle techniques

BACKGROUND

There has been growing interest in anatomical reconstruction of the anterior cruciate ligament (ACL), including the use of double-bundle (DB) reconstruction techniques.

HYPOTHESIS

The DB technique will not be cost-effective when compared with single-bundle (SB) reconstruction.

STUDY DESIGN

Economic and decision analysis; Level of evidence, 1.

METHODS

A decision-analysis model with input values derived from the literature was used to estimate the cost-effectiveness of DB ACL reconstruction compared with SB ACL reconstruction. Effectiveness was based on the revision rate and the postoperative International Knee Documentation Committee (IKDC) score.

RESULTS

Sixty-four percent of DB knees result in an IKDC score of A, compared with 54% of SB knees. The incremental cost-effectiveness ratio of a DB reconstruction compared with an SB reconstruction was $6416 per quality adjusted life year in the baseline scenario and $64 371 per quality adjusted life year in the alternate scenario. The model is very sensitive to the proportions of IKDC A outcomes. The model is also sensitive to the utility values assigned to IKDC A and B outcomes and is less sensitive to the marginal cost of a DB reconstruction.

CONCLUSION

This preliminary analysis based on published clinical results to date shows DB ACL reconstruction may be cost-effective, despite increased upfront cost. More research is needed to confirm whether there is any difference in the distribution of IKDC outcomes between the 2 techniques. Perhaps more importantly, the lack of any other demonstrated clinical benefit from the DB technique questions the clinical relevance of this difference in IKDC scores.

CLINICAL RELEVANCE

Revision data and longer term outcomes after DB reconstruction and more reliable clinical utility data are needed to definitively compare the cost-effectiveness of DB and SB ACL reconstruction. Studies of ACL reconstruction and other sports medicine procedures should report the distribution of outcomes data to facilitate future analyses of clinical effectiveness.

Descriptive epidemiology of the Multicenter ACL Revision Study (MARS) cohort

BACKGROUND

Revision anterior cruciate ligament (ACL) reconstruction has worse outcomes than primary reconstructions. Predictors for these worse outcomes are not known. The Multicenter ACL Revision Study (MARS) Group was developed to perform a multisurgeon, multicenter prospective longitudinal study to obtain sufficient subjects to allow multivariable analysis to determine predictors of clinical outcome.

PURPOSE

To describe the formation of MARS and provide descriptive analysis of patient demographics and clinical features for the initial 460 enrolled patients to date in this prospective cohort.

STUDY DESIGN

Cross-sectional study; Level of evidence, 2.

METHODS

After training and institutional review board approval, surgeons began enrolling patients undergoing revision ACL reconstruction, recording patient demographics, previous ACL reconstruction methods, intra-articular injuries, and current revision techniques. Enrolled subjects completed a questionnaire consisting of validated patient-based outcome measures.

RESULTS

As of April 1, 2009, 87 surgeons have enrolled a total of 460 patients (57% men; median age, 26 years). For 89%, the reconstruction was the first revision. Mode of failure as deemed by the revising surgeon was traumatic (32%), technical (24%), biologic (7%), combination (37%), infection (<1%), and no response (<1%). Previous graft present at the time of injury was 70% autograft, 27% allograft, 2% combination, and 1% unknown. Sixty-two percent were more than 2 years removed from their last reconstruction. Graft choice for revision ACL reconstruction was 45% autograft, 54% allograft, and more than 1% both allograft and autograft. Meniscus and/or chondral damage was found in 90% of patients.

CONCLUSION

The MARS Group has been able to quickly accumulate the largest revision ACL reconstruction cohort reported to date. Traumatic reinjury is deemed by surgeons to be the most common single mode of failure, but a combination of factors represents the most common mode of failure. Allograft graft choice is more common in the revision setting than autograft. Concomitant knee injury is extremely common in this population.

Anterior cruciate ligament graft reconstruction: clinical, technical, and imaging overview

The anterior cruciate ligament (ACL) is one of the most frequently torn ligaments of the knee. With more than 100,000 ACL reconstructions performed yearly in the United States, evaluation of ACL grafts with magnetic resonance imaging is a common occurrence in daily clinical practice. Anterior cruciate ligament reconstructions vary from single bundle, double bundle, selective bundle, and physeal-sparing techniques. Complications of ACL graft reconstructions include graft tears, graft laxity, arthrofibrosis, and hardware failure or migration. This article offers a comprehensive review of ACL reconstruction for the consulting radiologist.

Cost analysis of converting from single-bundle to double-bundle anterior cruciate ligament reconstruction

BACKGROUND

Recent studies comparing double-bundle anterior cruciate ligament reconstruction to single-bundle anterior cruciate ligament reconstruction have reported some biomechanical advantages but little or no short-term clinical benefit from the double-bundle technique. In the current healthcare environment, the potential economic implications of widespread conversion to a double-bundle anterior cruciate ligament reconstruction are an important consideration.

PURPOSE

To determine the economic implications of widespread use of the double-bundle technique for anterior cruciate ligament reconstruction.

STUDY DESIGN

Economic analysis; Level of evidence, 2.

METHODS

A cost model to assess the effect of double-bundle anterior cruciate ligament reconstruction was constructed using standard accounting methodology. The model was based on actual 2008 cost figures (in US dollars) for ligamentous allografts, fixation implants, and operating room time. Revision rate (4%) and time to revision surgery (mean, 4 years) for single-bundle anterior cruciate ligament reconstruction was based on the available literature. Assumptions about the prevalence of double-bundle versus single-bundle anterior cruciate ligament reconstruction, the number of grafts used, and the revision rate for double-bundle reconstruction were varied to assess their effect on cost.

RESULTS

The potential additional cost for widespread conversion to the double-bundle technique for anterior cruciate ligament reconstruction ranges from $36 million to $792 million per year in the United States alone. To offset this increased cost, the double-bundle technique would have to reduce the revision rate at a minimum from 4% to 1.5% and potentially from 24.1% to 0%.

CONCLUSION

Double-bundle anterior cruciate ligament reconstruction has the potential of adding considerable cost to the health-care system.

CLINICAL RELEVANCE

While further research is warranted to determine if there are other benefits from this technique, widespread adoption of a double-bundle anterior cruciate ligament reconstruction does not appear to be cost-effective at this time.

Repeat revision of anterior cruciate ligament reconstruction: a retrospective review of management and outcome of 10 patients with an average 3-year follow-up

BACKGROUND

To the authors' knowledge, no previous published study has focused on management and outcome of repeat revision of anterior cruciate ligament reconstruction in terms of functional result and meniscus and articular cartilage status.

HYPOTHESIS

Repeat revision of anterior cruciate ligament reconstruction improves knee stability, but with inferior results for functional outcome compared with primary anterior cruciate ligament reconstruction. Meniscal tears and subsequent articular cartilage degeneration are more prevalent with successive revisions due to recurrent laxity.

STUDY DESIGN

Case series; Level of evidence, 4.

MATERIALS AND METHODS

Between February 2003 and November 2006, a consecutive series of 10 patients with an average age at 30 years (range, 17-48) were operated on for a repeat revision of anterior cruciate ligament reconstruction (2 revisions after a primary reconstruction) with arthroscopic procedures. A clinical and a radiographic evaluation were performed to assess anterior cruciate ligament reconstruction failures, outcome of revisions, and causes of failures. Meniscal tears and articular cartilage lesions were analyzed.

RESULTS

The average follow-up of the second revision was 38 months (range, 12-61). At latest follow-up, final International Knee Documentation Committee assessment was excellent or good in 7 cases. Postoperatively, only 2 patients recovered to the same sports activity level they had before their first anterior cruciate ligament reconstruction. Four had a lower level, and 4 discontinued sports activity. The postoperative average side-to-side KT-1000 arthrometer maximum manual difference was 1.3 +/- 1.9 mm. Nine patients had meniscal tears and 7 had articular cartilage lesions. Meniscal tears, meniscectomies, and articular cartilage degeneration increased after the second revision (P = .016, P = .0098, and P = .0197, respectively). Severe articular cartilage degeneration (International Cartilage Repair Society grade III and IV lesions) was found in patients with bad functional outcome (final International Knee Documentation Committee assessment C or D) (P = .0472). Incidence of articular cartilage degeneration was found to be more prevalent in cases of meniscal tears and partial meniscectomy at the same tibiofemoral compartment (P = .0157). Index anterior cruciate ligament reconstruction and first revision failures were caused by recurrent trauma (60% and 70%, respectively) or a surgical technical error with tunnel malpositioning (40% and 10%, respectively).

CONCLUSION

Outcome of repeat revision of anterior cruciate ligament reconstruction was excellent or good in 70% of the cases, although decreased after the second revision, in relation to the occurrence of meniscal tears and articular cartilage lesions. Meniscal and articular cartilage lesions were more frequent and more severe with recurrent laxity. The cause of failures was mainly recurrent trauma, followed by surgical technical errors.