Management of bony deficiency in revision anterior cruciate ligament reconstruction using allograft bone dowels: surgical technique

Intraoperative and Postoperative Outcomes of Patients Undergoing Total Knee Arthroplasty With Prior Anterior Cruciate Ligament Reconstruction: A Matched Cohort Analysis

Background

Previous anterior cruciate ligament (ACL) injury is a risk factor for the development of knee osteoarthritis. Despite advances in ACL reconstruction (ACLR) techniques, many patients with history of ACLR develop end-stage osteoarthritis necessitating total knee arthroplasty (TKA). The purpose of this study was to investigate the impact of prior ACLR on intraoperative and postoperative outcomes of TKA.

Methods

This was a single-centre matched cohort study of all patients with prior ACLR undergoing primary TKA from January 2000 to May 2022. Patients were matched 1:1 to patients undergoing TKA with no prior ACL injury based on age, sex, and body mass index. Outcomes investigated included TKA procedure duration, soft-tissue releases, implant design, and complications requiring reoperation.

Results

Forty-two ACLR patients were identified and matched to controls. Mean follow-up was 6.8 years and 5.0 years in the ACLR and control cohorts, respectively (P = .115). ACLR patients demonstrated longer procedure durations (122.8 minutes vs 87.0 minutes, P < .001) and more frequently required soft-tissue releases (40.5% vs 14.3%, P = .007), stemmed implants (23.8% vs 4.8%, P = .013), and patellar resurfacing (59.5% vs 26.2%, P = .002). There were no significant differences in postoperative clinical or surgical outcomes between groups. Ten-year implant survivorship was 92% and 95% in the ACLR and control cohorts, respectively (P = .777).

Conclusions

TKA is an effective procedure for the management of end-stage osteoarthritis with prior ACLR. The care team should be prepared for longer operative times and the utilization of advanced techniques to achieve satisfactory soft-tissue balance and implant stability.

Management of Bone Loss and Tunnel Widening in Revision ACL Reconstruction

➤ Both mechanical and biological factors can contribute to bone loss and tunnel widening following primary anterior cruciate ligament (ACL) reconstruction.➤ Revision ACL surgery success is dependent on graft position, fixation, and biological incorporation.➤ Both 1-stage and 2-stage revision ACL reconstructions can be successful in correctly indicated patients.➤ Potential future solutions may involve the incorporation of biological agents to enhance revision ACL surgery, including the use of bone marrow aspirate concentrate, platelet-rich plasma, and bone morphogenetic protein-2.

Two-Stage Revision Anterior Cruciate Ligament Reconstruction with Cannulated Allograft Bone Dowels Soaked in Bone Marrow Aspirate Concentrate

Anterior cruciate ligament reconstruction (ACLR) is one of the most common orthopedic procedures performed each year. The majority of patients undergoing these reconstructions will experience long-term stability and symptomatic relief; however, some will require a revision ACLR procedure. In general, revision ACLRs are more challenging than primary ACLRs due to several diagnostic and technical considerations. A revision ACLR can be performed with either a one-stage or two-stage procedure, which is based on the presence or absence of malpositioned tunnels, bone loss, and tunnel expansion. Recently, the introduction of preshaped allograft bone dowels as a bone grafting option has gained popularity. They provide immediate structural stability and avoid donor site morbidity associated with autografts. The purpose of this article is to outline a bone-grafting tunnel technique with cannulated allograft bone dowels soaked in bone marrow aspirate concentrate (BMAC) used in the first stage of a staged revision ACLR procedure.

Single-Stage Anterior Cruciate Ligament Revision Reconstruction Using an Allograft Bone Dowel for a Malpositioned and Widened Femoral Tunnel

Tunnel widening, osteolysis, and/or malposition can be a cause of anterior cruciate ligament (ACL) reconstruction failure and a challenging problem to treat when performing revision ACL reconstruction (RACLR). Traditionally, problematic tunnels that interfere with bony stability and incorporation of the new graft at the time of revision have been treated with staged procedures-bone grafting first, followed by a return several months later for the revision reconstruction after bony incorporation has occurred. Multiple staged procedures increase the level of risk the patient may encounter and increase cost and resource utilization. In addition, they prolong the recovery period for the patient. In recent years, several studies have evaluated the clinical outcomes of performing bone grafting of tunnels and concomitant RACLR in a single-stage setting in an effort to mitigate these issues. We describe a technique by which a malpositioned and widened femoral tunnel from a primary ACL failure is treated with bone grafting using an allograft dowel, as well as immediate RACLR using a bone-patellar tendon-bone allograft.

Allograft Bone Dowels Show Better Incorporation in Femoral Versus Tibial Tunnels in 2-Stage Revision Anterior Cruciate Ligament Reconstruction: A Computed Tomography-Based Analysis

PURPOSE

The purpose of this study was to quantitatively evaluate the radiographic outcomes of allograft dowels used in 2-stage revision anterior cruciate ligament reconstruction (ACLR) and to compare the incorporation rates of dowels placed in tibial and femoral tunnels.

METHODS

Prospective review of patients who underwent 2-stage revision ACLR with allograft bone dowels. Inclusion criteria were tibial/femoral tunnel diameter of ≥14 mm on preoperative computed tomography (CT) or overlapping of prior tunnels with planned tunnels. Second-stage timing was determined based on qualitative dowel integration on CT obtained at ∼3 months after the first stage. Quantitative analysis of incorporation rates was performed with the union ratio (UR) and occupying ratio (OR) on postoperative CT scans.

RESULTS

Twenty-one patients, with a mean (SD) age of 32.1 (11.4; range, 18-50) years, were included. Second-stage procedures were performed at a mean (SD) of 6.5 (2.1; range, 2.4-11.5) months after first-stage revision. All dowels showed no signs of degradation at the host bone/graft junction at the second-stage procedure. The mean (SD) diameter of the dowels placed in tibial tunnels was greater than those placed in femoral tunnels (16.1 [2.3] mm vs 12.4 [1.6] mm; P < .05). CT was obtained at a mean (SD) of 121 (28; range, 59-192) days after the first-stage surgery. There was no difference between the OR of femoral and tibial tunnels (mean [SD], 87.6% [4.8%] vs 85.7% [10.1%]; P = .484), but the UR was significantly higher in femoral tunnels (mean [SD], 83% [6.2%] vs 74% [10.5%], P = .005). The intraclass correlation coefficients of OR and UR measurements indicated good reliability.

CONCLUSIONS

Allograft bone dowels are a viable graft choice to replenish bone stock in the setting of a staged revision ACL reconstruction. Allograft dowels placed in femoral tunnels had a higher healing union ratio than tibial tunnel allografts and no evidence of degradation at the bone/graft junction, with no difference seen in occupying ratio.

LEVEL OF EVIDENCE

Level IV, case series.

Editorial Commentary: Anterior Cruciate Ligament Tunnel Aperture Overlap Determines Need for 1- Versus 2-Stage Revision: Setting the Stage

Despite general agreement that tunnel widening ≥14 mm necessitates a 2-stage approach for revision anterior cruciate ligament (ACL) reconstruction, there is very little literature describing the effect of tunnel overlap between the previous tunnel and new tunnel with 1-stage ACL revisions. Tunnel overlap, particularly at the aperture, should be minimized without compromising anatomic tunnel location(s). This can often be accomplished with a 1-stage revision, but 2-stage revisions are sometimes required. Revision ACL reconstruction can be challenging and it is helpful for the surgeon to carefully plan preoperatively and have several options available to him/her intraoperatively, including the possibility of a 2-stage revision.

One-Stage Anatomical Revision Anterior Cruciate Ligament Reconstruction: Results According to Tunnel Overlaps

PURPOSE

To present clinical results according to tunnel overlap in 1-stage anatomical revision anterior cruciate ligament reconstruction (ACLR).

METHODS

All patients who underwent revision ACLR performed by a single surgeon (J.H.A.) from 2012 to 2017 and were followed up for >24 months were retrospectively evaluated. The exclusion criteria were concomitant ligament injury, including medial collateral ligament injury, modified Outerbridge grade ≥3 cartilage lesion, and severe meniscus defects. Tunnel overlap was measured on 3-dimensionally reconstructed computed tomography images. Patients in the nonoverlapped femoral tunnel group (group NO, n = 52) were treated with new tunnel drilling that completely avoided previous tunnels, and those in the overlapped femoral tunnel group (group O, n = 41) were treated with a new tunnel that overlapped with previous tunnels. Clinical outcomes were evaluated using the subjective International Knee Documentation Committee (IKDC) and Lysholm scores. Knee joint stability was measured using the Lachman and pivot shift tests. Patients with femoral tunnel widening of ≥14 mm underwent 2-stage ACLR.

RESULTS

The mean follow-up duration of 93 patients was 46.9 months (range, 24-97 months). All preoperative subjective and objective IKDC (P<0.001) and Telos stress test scores (P = .016) were significantly improved at the last follow-up. Forty-one patients had overlapping femoral tunnels, whereas 87 had overlapping tibial tunnels. At the last follow-up, subjective IKDC and Lysholm scores (73.6 ± 15.3 vs 74.9 ± 12.1, P = .799 and 80.0 ± 19.2 vs 81.44 ± 13.5, P = .505, respectively) and objective pivot shift (IKDC grade) in the Lachman test (P = .183 and P = .450, respectively) did not differ significantly between groups NO and O, respectively.

CONCLUSIONS

One-stage anatomical revision ACLR significantly improved the clinical results. Most tibial tunnels (94%) and approximately one-half (44%) of the femoral tunnels overlapped. The overlapped femoral tunnel group did not show inferior outcomes or stability.

LEVEL OF EVIDENCE

Level III, cohort study.

Single-Stage Revision Anterior Cruciate Ligament Reconstruction: Experience With 91 Patients (40 Elite Athletes) Using an Algorithm

BACKGROUND

The increased prevalence of anterior cruciate ligament (ACL) reconstruction has led to an increased need for revision ACL reconstructions. Despite the growing body of literature indicating that single-stage revision ACL reconstruction can yield good outcomes, there is a lack of data for determining when and how to safely perform a single-stage revision.

PURPOSE

To assess the outcomes, graft failure rates, and return-to-play rates of a decision-making algorithm for single-stage revision ACL reconstruction.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We reviewed a consecutive series of revision ACL reconstructions performed by the senior author between September 2009 and July 2016 with minimum 2-year follow-up. All patients were assessed, and decision making was undertaken according to the algorithm. Outcomes measured were further surgery, graft rerupture, re-revision, Tegner score, and Knee injury and Osteoarthritis Outcome Score (KOOS). For the elite athlete population, return-to-play time, duration, and level of play after surgery as compared with preinjury were also determined.

RESULTS

During this period, 93 procedures were performed in 92 patients (40 elite athletes). Two 2-stage procedures were undertaken, leaving 91 single-stage procedures (91 patients) to form the basis for further study. At a mean 4.3 years (SD, 2.2 years) after surgery, there had been 2 re-revisions (2.2%) and 2 further instances of graft failure that had not been re-revised (total graft failure rate, 4.4%). There were 17 subsequent procedures, including 6 arthroscopic partial meniscectomies, 5 removals of prominent implants, and 1 total knee arthroplasty. The mean Tegner score was 8.02 before graft rerupture and 7.1 at follow-up. At follow-up, the mean KOOS outcomes were 79.3 for Symptoms, 88.0 for Pain, 94.2 for Activities of Daily Living, 73.6 for Sport, and 68.9 for Quality of Life. Of 40 elite athletes, 35 returned to play at a mean 11.2 months (SD, 3.6 months) after surgery.

CONCLUSION

Single-stage revision ACL reconstructions can be performed reliably in the majority of patients, with good clinical outcomes, low rerupture rates, and high-return-to play rates, even in the elite athlete population.

Economic Reliable Technique for Tunnel Grafting Using Iliac Crest Bone Graft in Two-Staged Revision Anterior Cruciate Ligament Surgery

Revision anterior cruciate ligament surgery is a technically demanding procedure. Mal-positioned tunnels together with bone loss and its management are some of the difficulties and challenges faced. Two-staged procedures have successfully been used to tackle those challenges. We present a technique that is safe, reliable, reproducible, and economic in the management of bone defects faced in anterior cruciate ligament revision surgery by using iliac crest bone graft. Preoperative assessment of tunnel position and size is done by computed tomography. Tri-cortical iliac crest bone graft is harvested through a trap door. It is then shaped to fit the tunnels to be filled. It is tapered at the advancing end to facilitate introduction. Mounted on a passing pin and a drill bit, the graft is arthroscopically introduced into the femoral and tibial tunnels. The second stage is performed after the graft has incorporated, as seen on postoperative computed tomography, done at approximately 3 months after the first stage. Iliac crest provides a natural abundant reservoir for bone graft and has all the advantages of being an autograft. With good meticulous technique, complications can be avoided with less donor-site morbidity. This technique is safe, reliable, and reproducible. It provides an ample amount of graft and harvest does not rely on implants; hence, it is economic.

Two-stage revision anterior cruciate ligament reconstruction: Our experience using allograft bone dowels

The incidence of anterior cruciate ligament reconstruction (ACLR) is continuously increasing. As a result so has the need for revision ACLR, which unfortunately has worse functional outcomes and rate of return to sport. Revision ACLR can be performed as a single stage or in two stages. The latter is recommended in the presence of enlarged and/or malpositioned tunnels. We describe our surgical technique, experience and outcome of our first 19 patients in whom we used allograft bone dowels in the first stage of revision ACLR.

Autologous Bone Graft Versus Silicate-Substituted Calcium Phosphate in the Treatment of Tunnel Defects in 2-Stage Revision Anterior Cruciate Ligament Reconstruction: A Prospective, Randomized Controlled Study With a Minimum Follow-up of 2 Years

PURPOSE

To compare and evaluate knee laxity and functional outcomes between autologous bone graft and silicate-substituted calcium phosphate (Si-CaP) in the treatment of tunnel defects in 2-stage revision anterior cruciate ligament reconstruction (ACLR).

METHODS

This prospective, randomized controlled trial was conducted between 2012 and 2015 with a total of 40 patients who underwent 2-stage revision ACLR. The tunnels were filled with autologous iliac crest cancellous bone graft in 20 patients (control group) and with Si-CaP in the other 20 patients (intervention group). After a minimum follow-up period of 2 years, functional outcomes were assessed by KT-1000 arthrometry (side-to-side [STS] difference), the Tegner score, the Lysholm score, and the International Knee Documentation Committee score.

RESULTS

A total of 37 patients (follow-up rate, 92.5%) with an average age of 31 years were followed up for 3.4 years (range, 2.2-5.5 years). The KT-1000 measurement did not show any STS difference between the bone graft group (0.9 ± 1.5 mm) and the Si-CaP group (0.7 ± 2.0 mm) (P = .731). One patient in the intervention group (5%) had an STS difference greater than 5 mm. Both groups showed significant improvements in the Tegner score, Lysholm score, and International Knee Documentation Committee score from preoperative assessment to final follow-up (P ≤ .002), without any difference between the 2 groups (P ≥ .396). Complications requiring revision occurred in 4 control patients (22%) and in 2 patients in the intervention group (11%) (P = .660). No complications in relation to Si-CaP were observed.

CONCLUSIONS

Equivalent knee laxity and clinical function outcomes were noted 3 years after surgery in both groups of patients. Si-CaP bone substitute is therefore a safe alternative to autologous bone graft for 2-stage ACLR.

LEVEL OF EVIDENCE

Level I, prospective, randomized controlled clinical trial.

Single-stage revision anterior cruciate ligament reconstruction using bone grafting for posterior or widening tibial tunnels restores stability of the knee and improves clinical outcomes

PURPOSE

Revision ACL surgery may be complicated by tunnel malposition and/or tunnel widening and often requires a staged treatment approach that includes bone grafting, a period of several months to allow bone graft incorporation and then definitive revision ACL reconstruction. The purpose of this study was to evaluate the results of a single-staged ACL revision reconstruction technique using a cylindrical dowel bone graft for patients who have existing posteriorly placed and/or widened tibial tunnels in the tibia at a minimum of 2 years follow-up.

METHODS

Between 2010 and 2014, patients undergoing single-stage revision ACL reconstruction with the described technique were prospectively enrolled and evaluated. At a minimum of 24 months, patients were evaluated by physical examination, multiple clinical outcome instruments including KOOS, Tegner and Lysholm, and preoperative and postoperative MRIs.

RESULTS

At a mean of 35.1 months, 18 consecutive patients had no revision surgery and no subjective knee instability. There were statistically significant improvements in the Tegner (median 2, interquartile range 2.25; p < 0.01), Lysholm (20.0 ± 15.0; p < 0.01), KOOS symptoms scale (12.9 ± 11.8; p < 0.01), KOOS pain scale (15.4 ± 18.7; p < 0.01), KOOS ADL scale (13.5 ± 19.0; p < 0.01), KOOS sports scale (32.8 ± 26.4; p < 0.01), and KOOS QoL scale (18.1 ± 16.9; p < 0.01). Postoperative MRI demonstrated statistically significant anteriorization of the tibial tunnel and a statistically significant decrease in tunnel widening.

CONCLUSION

Revision ACL reconstruction utilizing a single-staged tibial tunnel grafting technique resulted in improved knee pain, function, and stability at a minimum of 24-month follow-up.

LEVEL OF EVIDENCE

IV.

Two-stage revision anterior cruciate ligament reconstruction

With the rising number of anterior cruciate ligament (ACL) reconstructions, revision ACL reconstructions are becoming increasingly common. A revision procedure may be performed to improved knee function, correct instability, and facilitate a return to normal activities. When performing a revision reconstruction, the surgeon decides between a single-stage or a two-stage revision. Two-stage revisions are rarely performed, but are particularly useful when addressing substantial tunnel-widening, active infection, and concomitant knee pathology (e.g., malalignment, other ligamentous injuries, meniscal or chondral lesions). Among these potential scenarios requiring a two-stage revision, tunnel-widening is the most common cause; the first stage involves graft removal, tunnel curettage, and bone grafting, followed by revision ACL reconstruction in the second stage. The purpose of this article is to review the preoperative planning, surgical considerations, rehabilitation, and outcomes of two-stage revision ACL reconstructions and summarize the recent literature outlining treatment results.

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.

One-stage revision anterior cruciate ligament reconstruction in cases with excessive tunnel osteolysis. Results of a new technique using impaction bone grafting

BACKGROUND

This level IV study describes a new one-stage procedure for revision ACL reconstruction in cases with extreme tunnel widening.

METHODS

Eight consecutively treated subjects requiring ACL revision and presenting with excessive tunnel widening (87.5% to 250% tunnel enlargement) were included in this study. The graft-tunnel mismatch was resolved in this one-stage revision procedure by the use of custom-made eight to 10 mm cylindrical shaped bone allografts in a press-fit construct with the ACL-graft in combination with the usual fixation devices for ACL-reconstruction. All subjects were evaluated pre-operatively and at a minimum follow-up of one year by the IKDC objective and subjective scores, KOOS, and Tegner activity scale.

RESULTS

Mean improvement was 24.8 ± 16.1 on the KOOS evaluation (P-value 0,006) and 38.1 ± 16.8 on the IKDC subjective score (P-value 0,001). The objective IKDC scores improved significantly with an average of one grade (P-value 0,038). Anterior laxity as determined on the KT-1000 arthrometer improved with an average of 3.63 mm compared to the situation before primary reconstruction, and the Pivot-shift test was negative in all but one patient after the revision procedure while positive in all patients before primary reconstruction.

CONCLUSION

This new surgical technique using eight to 10 mm allograft bone cylinders for the management of excessive tunnel enlargement at single stage revision ACL reconstruction delivers excellent results after minimum one year of follow-up. The results of this study have the potential to lower the threshold for one-stage surgery in ACL revision complicated by extreme tunnel widening.

Supercritical Carbon Dioxide-Sterilized Bone Allograft in the Treatment of Tunnel Defects in 2-Stage Revision Anterior Cruciate Ligament Reconstruction: A Histologic Evaluation

PURPOSE

To examine the histologic properties of supercritical carbon dioxide (sCO₂)-sterilized bone allograft for tunnel grafting and determine in vivo graft quality, as well as graft incorporation and remodeling, in 2-stage revision anterior cruciate ligament (ACL) surgery.

METHODS

Histologic evaluation was performed in 12 subjects undergoing 2-stage revision ACL reconstruction. In the first stage, the femoral and tibial tunnels were debrided, tunnel dimensions were measured, and tunnels were grafted with sCO₂-sterilized bone allograft. In the second stage, revision ACL reconstruction was performed and bone biopsy specimens were taken from the tibia. Tissue, bone, and graft volumes were measured, and histomorphometric analysis was performed.

RESULTS

The mean time between the 2 stages was 8.8 months (range, 5.6-21.3 months). In the second stage, bone graft material was easily identified by its necrotic appearance comprising mature lamellar bone devoid of osteocyte nuclei within osteocyte lacunae. In all tissue samples, host-bone apposition of predominantly mature lamellar bone was noted on the surface of graft fragments in keeping with "creeping substitution." In several regions in 3 cases, osteoblastic and osteoclastic activity was evident in keeping with ongoing creeping substitution and remodeling. The mean bone volume over tissue volume was 68% (range, 33%-92%), and the mean graft volume over bone volume was 41% (range, 19%-70%). The mean graft volume (8 cases) harvested at less than 7 months (44%; 95% confidence interval, 31.4%-56.8%) was not significantly different than the mean graft volume (4 cases) harvested at greater than 10 months (34%; 95% confidence interval, 14.3%-54.2%; P = .214).

CONCLUSIONS

The sCO₂-sterilized bone allograft showed graft incorporation and remodeling through creeping substitution.

CLINICAL RELEVANCE

The initial bone apposition and graft fragment bridging appear to provide a strong environment for ACL graft fixation resulting in technically successful 2-stage revision ACL reconstruction.

Two-Stage Revision Anterior Cruciate Ligament Reconstruction Using Allograft Bone Dowels

Revision anterior cruciate ligament (ACL) reconstruction is substantially more challenging than primary reconstruction. Management of previously malpositioned or widened tunnels often requires innovative approaches for managing bony defects. Massive osteolysis with poor bone stock and convergence or overlapping of revision tunnels into the previously placed tunnels may necessitate a staged revision procedure. In this surgical technique description, we describe a method for the management of bony deficiencies using allograft bone dowels in staged revision ACL reconstruction.

Bone Incorporation of Silicate-Substituted Calcium Phosphate in 2-Stage Revision Anterior Cruciate Ligament Reconstruction: A Histologic and Radiographic Study

PURPOSE

To evaluate the histologic and radiographic outcomes of using silicate-substituted calcium phosphate (Si-CaP) as bone graft substitute for the augmentation of tunnel defects in 2-stage revision anterior cruciate ligament (ACL) reconstruction.

METHODS

Forty patients undergoing 2-stage revision ACL reconstruction were included in a prospective, randomized controlled clinical trial between 2012 and 2015. The inclusion criteria were tunnel diameter of the tibial and/or femoral tunnel of 10 mm or greater after failed ACL reconstruction. Twenty patients received autologous bone from the iliac crest and 20 patients received Si-CaP as a bone graft substitute for tunnel grafting at the first-stage procedure. Punch biopsy specimens of the augmented tunnels were taken at the second-stage procedure, and histologic examination included quantitative analysis of the area of immature bone formation, lamellar bone, and bone marrow. Radiographic analysis included determination of the filling rates of the tunnels on postoperative computed tomography scans.

RESULTS

Forty patients with a mean age of 32 years (standard deviation [SD], 11.0 years) were analyzed. Histologic examination of the tunnels filled with Si-CaP showed that 15% (SD, 14%) of the area was covered with immature bone formation, 41% (SD, 10%) with well-organized lamellar bone, and 44% (SD, 8%) with bone marrow. In the control group (autologous bone), 58% (SD, 3%) of the area was covered with well-organized lamellar bone and 42% (SD, 3%) with bone marrow. Quantitative evaluation of the postoperative computed tomography scans showed a trend of better filling rates in patients with Si-CaP for the tibial tunnel (86% [SD, 17%] vs 78% [SD, 14%]; P = .131). Intraoperatively, Si-CaP was completely integrated into the original bone tunnel providing good stability for tunnel placement and tendon graft fixation comparable to autologous bone.

CONCLUSIONS

Si-CaP as bone graft substitute for tunnel augmentation in 2-stage revision ACL reconstruction shows good histologic, radiographic, and intraoperative integration comparable to autologous bone.

LEVEL OF EVIDENCE

Level I, prospective randomized controlled trial.

Causes of Failure of Anterior Cruciate Ligament Reconstruction and Revision Surgical Strategies

Purpose

Long-term outcomes of anterior cruciate ligament (ACL) reconstruction are good or excellent; however, 0.7%–20% of patients suffer from recurrent instability due to graft failure. The purpose of this paper was to analyse failure aetiology and the possibilities of revision surgical strategies, with a description of our experience. We obtained optimal and good results in most of our patients.

Materials and Methods

We retrospectively reviewed 42 patients who underwent revision surgery (43 revisions) due to relapsing instability after ACL reconstruction between 2006 and 2015. We used allografts in 39 cases and autografts in 4 cases.

Results

The 85.7% of the patients obtained optimal results (normal knee; group A) and the 7.2% obtained good results (nearly normal knee; group B) according to the International Knee Documentation Committee score. The most frequent failure causes were traumatic events, non-anatomic tunnel placement, and lack of graft incorporation.

Conclusions

A correct revision surgery requires accurate patient evaluation and knee imaging. Preoperative planning starts with the identification of the cause of failure of the primary reconstruction. Then, the most suitable procedure should be determined for each case. It is also important to accurately inform the patient of all the complexity of an ACL revision surgery even if it is a procedure with high rates of excellent and good outcomes.

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.

Revision Anterior Cruciate Ligament Reconstruction: Results of a Single-stage Approach Using Allograft Dowel Bone Grafting for Femoral Defects

INTRODUCTION

The purpose of this study was to present results of single-stage revision anterior cruciate ligament (ACL) reconstruction using an allograft bone dowel for isolated femoral bony deficiency.

METHODS

Sixteen patients underwent single-stage revision ACL reconstruction using an allograft bone dowel for isolated femoral bony deficiency between 2007 and 2012. Twelve patients (75%) completed study visits, which included CT scans as well as completion of validated outcomes measures.

RESULTS

The average KT-1000 side-to-side difference was 1.0 mm ± 2.9 mm. The average International Knee Documentation Committee score was 70.2 ± 17.8, the Tegner score was 4.8 ± 2.8, and the visual analog scale pain score was 2.8 ± 2.4. An analysis of CT scans showed that all 12 dowels had excellent (>75%) incorporation.

CONCLUSIONS

A single-stage approach for revision ACL reconstruction using allograft dowels for isolated femoral bony deficiency yields objective and subjective outcomes comparable to those reported in the literature for two-stage and other single-stage techniques, with good incorporation of the dowels.

LEVEL OF EVIDENCE

Retrospective case series, level IV.

Two-Stage Revision Anterior Cruciate Ligament Reconstruction

The number of primary anterior cruciate ligament (ACL) tears is rapidly increasing. In patients who wish to return to their preoperative level of function, specifically as it pertains to participation in sports, the gold standard of treatment following an ACL tear remains an anterior cruciate ligament (ACL) reconstruction. Despite a majority of good/excellent results following primary ACL reconstruction, there is a growing subset of patients with persistent or recurrent functional instability who require revision ACL reconstruction. Preoperative planning for revision ACL reconstruction requires a careful understanding of the root cause of ACL failure, including possible technical causes of primary ACL failure and the presence of combined knee pathology that was not addressed at the index ACL reconstruction. The decision to perform 2-stage revision ACL reconstruction is multifactorial and is reached by technical considerations that may make a 1-stage revision less optimal, including tunnel widening, arthrofibrosis, active infection, and others. Concomitant knee pathology such as meniscal deficiency, malalignment (including an increase in posterior tibial slope), chondral lesions, and other ligamentous laxity may also require a staged approach to treatment. This evidence-based review covers the indications for 2-stage revision ACL reconstruction, surgical techniques, evidence for and technique of bone grafting prior ACL tunnels, and outcomes of 2-stage revision stratified by initial cause of ACL reconstruction failure. With proper preoperative planning and an understanding of the cause of failure following the primary ACL reconstruction, revision ACL reconstruction can offer excellent outcomes in the motivated patient. [Orthopedics. 2016; 39(3):e456-e464.].

Two-Stage Revision Anterior Cruciate Ligament Reconstruction: Bone Grafting Technique Using an Allograft Bone Matrix

Outcomes of primary anterior cruciate ligament (ACL) reconstruction have been reported to be far superior to those of revision reconstruction. However, as the incidence of ACL reconstruction is rapidly increasing, so is the number of failures. The subsequent need for revision ACL reconstruction is estimated to occur in up to 13,000 patients each year in the United States. Revision ACL reconstruction can be performed in one or two stages. A two-stage approach is recommended in cases of improper placement of the original tunnels or in cases of unacceptable tunnel enlargement. The aim of this study was to describe the technique for allograft ACL tunnel bone grafting in patients requiring a two-stage revision ACL reconstruction.

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

Background

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

Methods

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

Results

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

Conclusion

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

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.

Revision anterior cruciate ligament reconstruction using tibial or hamstring tendon allografts

PURPOSE

To report outcomes of revision anterior cruciate ligament (ACL) reconstruction using tibial or hamstring tendon allografts and to compare with another study using non-irradiated fresh-frozen bone-patellar tendon-bone allografts.

METHODS

Records of 12 men and 7 women aged 18 to 53 (mean, 33) years who underwent revision ACL reconstructions using tibial tendon (n=17) or hamstring tendon (n=2) allografts were retrospectively reviewed. At the time of primary ACL reconstruction, hamstring autografts (n=8) and bonepatellar tendon-bone allografts (n=11) were used. The mean time interval between surgeries was 93 (range, 11-225) months. The causes of failure were traumatic injury (n=7) and technical or biological reasons (n=12). The physical activity level was high in 2 patients, medium in 10, and low in 7. For clinical assessment, the Lysholm test, International Knee Documentation Committee (IKDC) scale, and visual analogue scale (VAS) for pain were used. Patient satisfaction was also assessed.

RESULTS

Four of the patients had laxity and were dissatisfied or very dissatisfied with the outcome; the failure rate was 21%. The mean IKDC score was 63% (range, 25-100%), and the mean Lysholm score was 74% (range, 30-100%). Comparing our patients with those in another study using bone-patellar-bone allografts, there was no significant difference in terms of the VAS for pain, IKDC score, and Lysholm score. Comparing our patients with and without chondral and/or meniscal lesions, there was significant difference in terms of the Lysholm score only (86±11 vs. 57±28, p=0.043). Comparing patients who had used hamstring tendon autografts at the primary ACL reconstruction with those who had used bonepatellar tendon-bone autografts, there was significant difference in terms of the VAS for pain only (4.4±3.1 vs. 1.6±1.0, p=0.020).

CONCLUSION

Revision ACL reconstruction using tibial or hamstring tendon allografts provided acceptable results, similar to those using the bone-patellar tendon-bone allografts.

One-stage revision anterior cruciate ligament reconstruction with impacted bone graft after failed primary reconstruction

Revision anterior cruciate ligament reconstruction can be performed in a 1- or 2-stage procedure. Restoration of bone stock using bone grafting is often required for good results. The authors performed 1-stage revision surgery with a more lateral and oblique femoral tunnel and an impacted bone graft to avoid the bone defect caused by the previous screw removal from a malpositioned tunnel. No evidence existed of revision surgery failure or viral transmission in any of 17 cases at 2-year follow-up. The authors' technique is also useful for a slightly misplaced femoral tunnel.

Technique of anatomical footprint reconstruction of the ACL with oval tunnels and medial portal aimers

PURPOSE

The purpose of this article was to demonstrate an anterior cruciate ligament (ACL) reconstruction technique using oval tunnels. Aim of this single bundle technique is to fit the footprint anatomy of the ACL as closely as possible. TECHNIQUE AND PATIENTS: The presented technique is a single bundle technique using a semitendinosus graft. For femoral tunnel placement, a specific medial portal aimer (Karl Storz, Tuttlingen, Germany) is used. Aiming and drilling of the femoral tunnel are performed via the medial portal. Oval tunnels are created by stepwise dilatation with ovally shaped dilatators. The position of the femoral tunnel is visualized and controlled with the arthroscope via the medial portal. For the tibial tunnel placement, a specific aimer was used as well. With this technique, 24 patients were operated and all intra- and postoperative complications were analyzed prospectively. The tunnel position was documented postoperatively by CT scan.

RESULTS

There were no significant intra- and postoperative complications associated with the oval tunnel technique. The postoperative 3D CT scan revealed that all femoral and tibial tunnels were located within the area of the anatomical ACL insertions.

CONCLUSIONS

This article presents an ACL reconstruction technique using oval dilatators and medial portal aimers to create oval tunnels. These oval tunnels match the insertion site anatomy much closer than round tunnels do.

LEVEL OF EVIDENCE

Level IV, case series.

Outcomes of repeat revision anterior cruciate ligament reconstruction

BACKGROUND

As anterior cruciate ligament (ACL) reconstruction is performed increasingly in the United States, the rate of revision ACL reconstruction continues to rise. A paucity of literature exists with respect to repeat ACL revision surgery.

PURPOSE

To evaluate the functional outcomes of patients who had undergone at least 2 revision ACL reconstructions.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The records of all patients who had undergone repeat revision ACL reconstructions between 1998 and 2009 were retrospectively reviewed. Data collected included patient demographics, operative findings, pre- and postoperative physical examination findings, radiographs, and Tegner, Lysholm, and International Knee Documentation Committee (IKDC) subjective scores.

RESULTS

Fifteen patients had undergone repeat revision ACL reconstruction during the study period. Mean age was 27 years (range, 18-57 years). Mean follow-up was 5 years (range, 2-10 years). At the time of repeat revision surgery, new tunnels were drilled in 9 of 15 (60%) cases. Of those, 8 of 9 (89%) were drilled because femoral tunnels were deemed "too anterior." During repeat revision, 11 of 15 (73%) patients were noted to have a meniscal tear, and 9 of 15 (67%) had International Cartilage Repair Society (ICRS) grade 3 or 4 chondral lesions. Mean Lysholm score was 60 preoperatively and increased to 82 postoperatively (P < .001). Mean preoperative IKDC score was 59, which increased to 80 postoperatively (P < .001). Mean preoperative Tegner score was 6.0. Mean postoperative Tegner score was 4.5, with only 4 of 15 (27%) patients having returned to their prior activity level (P < .001). Two patients (13%) sustained a traumatic rerupture. Presence of grade 3 or 4 chondral lesions and body mass index greater than 28 at the time of repeat revision were associated with a "fair" or "poor" outcome by Lysholm score (P = .007 and P = .03, respectively) and IDKC subjective scoring (P = .04 and P = .007, respectively).

CONCLUSION

Repeat revision ACL reconstruction may improve the functional outcomes of patients who have failed revision ACL reconstruction. Most patients do not return to prior activity level following repeat revision. Presence of grade 3 or 4 chondral lesions and body mass index greater than 28 were associated with worse outcomes.

Evaluation of a one-stage ACL revision technique using bone void filler after cyclic loading

BACKGROUND

Revision anterior cruciate ligament (ACL) reconstruction often requires a two-stage approach. This study analyzes the biomechanical properties after cyclic loading of a one-stage ACL revision technique using a calcium phosphate bone cement.

METHODS

Arthroscopic reconstruction of the ACL was performed in 5 matched pairs of fresh-frozen cadaveric knees separated into two groups. The control group underwent a standard reconstruction with a bone-patellar tendon-bone autograft with bioabsorbable interference screw fixation. The experimental group simulated a failed reconstruction by drilling a 12 mm hole and underwent a revision after filling it with a bioabsorbable calcium phosphate bone cement. The specimens were dissected, scanned for bone mineral density, and cyclically loaded on a mechanical testing system (preload of 250 cycles of 5-75 N at 0.5 Hz followed by 10,000 cycles of 20-150 N at 1 Hz). Intact specifmens underwent a load-to-failure protocol of 50mm/min. Ultimate load, stiffness, and modes of failure were recorded. Data was analyzed using paired t-tests.

FINDINGS

All specimens completed the mechanical testing protocol. The control group had a mean maximum load of 471.33 N (SD 220.73 N) and the experimental group had 453.54 N (SD 152.36; p=0.84). There were no statistically significant differences in maximum load or stiffness. No correlation between bone mineral density (BMD) and maximum load was found.

INTERPRETATION

Using calcium phosphate filler in a single-stage ACL revision is biomechanically viable. Further testing of long-term incorporation of the ACL graft in an animal model, along with human clinical trials, should be performed before there is clinical acceptance of this technique.

Surgical technique: revision ACL reconstruction with a rectangular tunnel technique

BACKGROUND

We developed the rectangular tunnel ACL reconstruction (RT ACLR) using a 10-mm wide bone-patellar tendon-bone (BTB) graft through rectangular tunnels with a rectangular aperture to reduce tunnel size: the cross-sectional area of the tunnels of 50 mm(2) (5 × 10 mm) in RT ACLR is less than that of 79 mm(2) in a conventional 10-mm round tunnel technique presuming the technique would be more suitable in revision ACLR with previous improperly placed tunnels.

DESCRIPTION OF TECHNIQUE

Two contiguous 5-mm tunnels inside the anatomic ACL femoral and tibial attachment areas along their long axes, and they are expanded with a 5 × 10-mm dilator into parallelepiped ones.

PATIENTS AND METHODS

We indicated and intended to perform the RT ACLR procedure in 31 patients requiring revision between 2004 and 2008. Eighteen of the 31 patients treated with the procedure were followed a minimum of 24 months (mean, 38 months; range, 24 to 73 months). We evaluated ROM, obtained IKDC scores, and determined stability with KT-1000.

RESULTS

The procedure could be applied in 30 of the 31 cases. One of the 18 reruptured the graft at 28 months. Of the remaining 17 patients with followup of 24 months or longer, 15 had full ROM, while the remaining two lost 5° of flexion; 11 were classified as normal and six were nearly normal according to the IKDC evaluation. Stability measured with KT-1000 was 1.0 ± 1.5 mm.

CONCLUSION

The RT ACLR technique provided acceptable results after one-stage revision ACLR.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

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.

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.

Biomechanical evaluation of a 1-stage revision anterior cruciate ligament reconstruction technique using a structural bone void filler for femoral fixation

PURPOSE

The purpose of this study was to develop a method of femoral fixation for complex revision anterior cruciate ligament (ACL) reconstructions that would avoid a staged bone grafting approach. We evaluated the use of a calcium phosphate cement as a structural bone void filler that would allow for a single-stage revision ACL reconstruction with initial biomechanical properties equivalent to standard autologous bone-patellar tendon-bone primary ACL reconstruction.

METHODS

We tested 11 matched pairs of fresh-frozen cadaveric knees (N = 22). Controls were treated with autologous bone-patellar tendon-bone primary ACL reconstruction fixed with bioabsorbable interference screws with a 1-mm back wall. The contralateral knee of each pair had a large bone void created that would hamper subsequent femoral fixation to simulate revision ACL reconstruction conditions. This defect was filled with calcium phosphate cement arthroscopically. After solidification, the femoral tunnel was drilled through the bone void filler and native bone with a 1-mm back wall, allowing anatomic positioning. The autologous graft was then placed and fixed with a bioabsorbable interference screw. Specimens were then tested in an MTS machine (MTS Systems, Eden Prairie, MN) for load to failure according to a standard protocol and compared with matched controls.

RESULTS

Failure loads for the control group averaged 312 N (standard deviation [SD], 127 N) and were not significantly different compared with the calcium phosphate cement revision group, which averaged 301 N (SD, 95 N) (P = .80). Failure occurred at the femoral bone block in both groups but without screw pullout.

CONCLUSIONS

Statistical analysis failed to show a significant difference between the control group and the group undergoing structural bone void filler revision in this biomechanical evaluation of initial fixation strength.

CLINICAL RELEVANCE

This technique may allow surgeons to perform a single-stage revision ACL reconstruction in the presence of a contained bone void and avoid the need for a staged procedure if clinical studies verify long-term incorporation of the bone void filler.

A simple and effective technique of femoral tunnel bone grafting in revision anterior cruciate ligament reconstruction

Restoring the bone stock in the femoral tunnel during revision anterior cruciate ligament reconstruction is vital for better surgical results and to avoid potential complications. The technique must be easy, effective, simple, reproducible and cost effective. We describe a new, simple and inexpensive technique of femoral tunnel bone grafting in revision ACL reconstruction using universally available materials.

Anterior cruciate ligament revision reconstruction: results in 107 patients

BACKGROUND

Although techniques and options for suitable graft substitutes for anterior cruciate ligament surgery continue to improve, failures occur because of many reasons. Errors in surgical techniques seem to be important reasons.

HYPOTHESIS

Inappropriate positioning of the tunnels may be the most important reason for these failures. Anatomical anterior cruciate ligament revision reconstruction, using autografts, may yield acceptable outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This retrospective study involved 148 anterior cruciate ligament revision reconstructions performed in our hospital using autografts. One hundred and seven patients were followed up at a mean of 72.9 +/- 20.6 months. Clinical evaluation was performed using the Lysholm score, the Tegner rating system, the International Knee Documentation Committee evaluation form, and the KT-1000 arthrometer. Radiographs were evaluated for signs of osteoarthritis according to the Jaeger and Wirth classification.

RESULTS

Inappropriate positioning of the tunnels was the most important reason (63.5%) for anterior cruciate ligament reconstruction failure. The average Lysholm score improved significantly at the follow-up (88.5 +/- 12.4 vs 51.5 +/- 24.9; P < .001). Moreover, the average Tegner activity score improved significantly compared with the activity score before revision surgery (6.3 +/- 1.8 vs 2.8 +/- 1.8; P < .001). The International Knee Documentation Committee score was A in 17 cases, B in 45, C in 37, and D in 8. Radiographic evaluation revealed that 33 patients had degenerative findings of grade I, 35 of grade II, 16 of grade III, and 2 of grade IV.

CONCLUSION

Anatomical anterior cruciate ligament revision reconstruction provides satisfactory midterm results as far as stability and function of the knee are concerned. In spite of these favorable subjective and objective results, the radiological evaluation revealed a significant progression of osteoarthritis.

A novel technique for arthroscopically assisted femoral bone tunnel grafting in two-stage ACL revision

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Femoral tunnel defect filled with a synthetic dowel graft for a single-staged revision anterior cruciate ligament reconstruction

Bone defects are a common obstacle to successful revision anterior cruciate ligament (ACL) reconstruction. We describe the use of a synthetic bone graft plug to fill a cylindric defect after femoral interference screw removal. During revision ACL reconstruction performed through a 2-incision technique, we placed an outside-in guidewire for a new femoral tunnel that converged with the femoral screw from the primary ACL reconstruction. The screw was removed, and the resultant defect appeared very similar to the cylindric bone defect left after an osteochondral graft harvest. The confluence of the defect and the planned femoral tunnel would have allowed a "windshield wiper" effect of the graft at the lateral wall of the notch. We filled the screw defect with a synthetic bone graft plug to limit the aperture size of the femoral tunnel and to buttress the tendinous portion of the revision ACL graft, while maintaining proper anatomic graft position. In this article, we present a readily available all-arthroscopic option for repairing cylindric bone defects without the risk of an allograft or the morbidity of an autograft for a single-stage revision ACL reconstruction.

A new harvest site for bone graft in anterior cruciate ligament revision surgery

During revision anterior cruciate ligament (ACL) surgery, femoral interference screws frequently require removal. This may lead to significant tunnel widening and possible graft fixation failure as a result. Solutions include drilling the revision tunnel in a different location, using stacked interference screws, or using bone graft to fill the defect. Autogenous iliac crest graft and allograft are both used, but there are significant comorbidities associated with each. We developed a new technique for harvesting autogenous bone graft that avoids many of the complications associated with other graft sources. By use of the existing surgical incision from the initial harvest of the bone-patellar tendon-bone autograft, bone from the medial tibial metaphyseal safe zone is harvested via an OATS tube harvester (Arthrex, Naples, FL). A bone plug 1 mm larger in size than the femoral defect is harvested and arthroscopically inserted via a press-fit technique. At 3 months after bone grafting, patients undergo revision ACL reconstruction. The proximal tibial metaphysis is a safe bone graft harvest site in revision ACL surgery and offers an effective method for filling large bony defects, allowing anatomic reconstruction of the ACL after bone healing has occurred. Furthermore, it eliminates the problems associated with allograft or use of a remote graft donor site.

Current concepts review: revision anterior cruciate ligament reconstruction

Failed anterior cruciate ligament (ACL) reconstruction presents a difficult clinical challenge. Successful revision ACL reconstruction depends on identifying the causes of failure and correcting technical or diagnostic errors. Failed ACL reconstruction may be either traumatic or atraumatic. Atraumatic failures may be attributable to technical errors, diagnostic errors, or failure of graft incorporation. Published outcomes of revision ACL reconstruction have been worse than for primary ACL reconstruction. The preoperative evaluation, surgical techniques, and clinical outcomes of revision ACL reconstruction are reviewed.

A new technique for femoral and tibial tunnel bone grafting using the OATS harvesters in revision anterior cruciate ligament reconstruction

Revision anterior cruciate ligament (ACL) reconstruction is becoming more frequent, especially in specialized centers, because of the large numbers of primary ACL procedures performed. In 2-stage revisions, bone grafting of the tunnels may be undertaken if the primary position was inaccurate or if osteolysis has caused widening of the tunnels. This will allow the desired placement of the new tunnels without the risk of loss of structural integrity. It is technically difficult to deliver and impact bone graft into the femoral tunnel with the standard surgical and arthroscopic instruments. We describe a new technique for femoral and tibial tunnel impaction grafting in 2-stage ACL revisions, using the OATS grafting instruments (Osteochondral Autologous Transfer System; Arthrex, Naples, FL). The appropriately sized OATS harvester is chosen 1 mm larger than the tunnel size and is used to harvest bone graft from the iliac crest through a percutaneous approach. This provides a cylindrical graft, which is delivered to the femoral tunnel through the arthroscopic portal. The inside punch of the harvester is tapped and this allows delivery of the graft in a controlled manner and its impaction into the tunnel. The same is repeated for the tibial tunnel while providing support for the proximal end of the tunnel.