The course of the patellar tendon after reharvesting its central third for ACL revision surgery: a long-term clinical and radiographic study

Near complete quadriceps tendon healing 2 years following harvest in anterior cruciate ligament reconstruction

PURPOSE

Despite the recent increase in the use of quadriceps tendon (QT) autograft in anterior cruciate ligament reconstruction (ACLR); however, there remains a paucity of literature evaluating the postoperative morphology of the QT. The present study aimed to determine the postoperative morphologic change of the QT at a minimum of 2 years following harvesting during ACLR.

METHODS

Patients who underwent ACLR with QT autograft and underwent magnetic resonance imaging (MRI) at a minimum of 2 years following harvesting were retrospectively included in the study. The anterior-to-posterior (A-P) thickness, medial-to-lateral (M-L) width, cross-sectional area (CSA), and signal/noise quotient (SNQ) of the QT were assessed at 5 mm, 15 mm, and 30 mm proximal to the superior pole of the patella on MRI. The CSA was adjusted by the angle between the QT and the plane of the axial cut based on a cosine function (adjusted CSA). The A-P thickness, M-L width, adjusted CSA, and SNQ were compared pre- and postoperatively. In addition, defects or scar tissue formation in the harvest site were investigated on postoperative MRI.

RESULTS

Thirty patients were recruited for the study. The mean duration between postoperative MRI and surgery was 2.8 ± 1.1 years. The mean A-P thickness was 10.3% and 11.9% larger postoperatively at 5 mm and 15 mm, respectively. The mean M-L width was 7.3% and 6.5% smaller postoperatively at 5 mm and 15 mm, respectively. There were no significant differences in the adjusted CSA between pre- and post-operative states (275.7 ± 71.6 mm2 vs. 286.7 ± 91.8 mm2, n.s.). There was no significant difference in the postoperative change in the SNQ of the QT at all assessment locations. Defect or scar tissue formation at the harvest site was observed in 4 cases (13.3%), and 5 cases (16.6%), respectively.

CONCLUSION

At a minimum of 2 years following QT harvest during ACLR, the QT became slightly thicker and narrower (approximately 11% and 7%, respectively). While the current study demonstrates that QT re-harvesting can be considered due to nearly normalized tendon morphology, future histological and biomechanical studies are required to determine the re-harvesting potential of the QT.

LEVEL OF EVIDENCE

IV.

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.

Meniscal and Articular Cartilage Predictors of Outcome After Revision ACL Reconstruction: A 6-Year Follow-up Cohort Study

BACKGROUND

Meniscal and chondral damage is common in the patient undergoing revision anterior cruciate ligament (ACL) reconstruction.

PURPOSE

To determine if meniscal and/or articular cartilage pathology at the time of revision ACL surgery significantly influences a patient's outcome at 6-year follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients undergoing revision ACL reconstruction were prospectively enrolled between 2006 and 2011. Data collection included baseline demographics, surgical technique, pathology, treatment, and scores from 4 validated patient-reported outcome instruments: International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx Activity Rating Scale. Patients were followed up at 6 years and asked to complete the identical set of outcome instruments. Regression analysis assessed the meniscal and articular cartilage pathology risk factors for clinical outcomes 6 years after revision ACL reconstruction.

RESULTS

An overall 1234 patients were enrolled (716 males, 58%; median age, 26 years). Surgeons reported the pathology at the time of revision surgery in the medial meniscus (45%), lateral meniscus (36%), medial femoral condyle (43%), lateral femoral condyle (29%), medial tibial plateau (11%), lateral tibial plateau (17%), patella (30%), and trochlea (21%). Six-year follow-up was obtained on 79% of the sample (980/1234). Meniscal pathology and articular cartilage pathology (medial femoral condyle, lateral femoral condyle, lateral tibial plateau, trochlea, and patella) were significant drivers of poorer patient-reported outcomes at 6 years (IKDC, KOOS, WOMAC, and Marx). The most consistent factors driving outcomes were having a medial meniscal excision (either before or at the time of revision surgery) and patellofemoral articular cartilage pathology. Six-year Marx activity levels were negatively affected by having either a repair/excision of the medial meniscus (odds ratio range, 1.45-1.72; P≤ .04) or grade 3-4 patellar chondrosis (odds ratio, 1.72; P = .04). Meniscal pathology occurring before the index revision surgery negatively affected scores on all KOOS subscales except for sports/recreation (P < .05). Articular cartilage pathology significantly impaired all KOOS subscale scores (P < .05). Lower baseline outcome scores, higher body mass index, being a smoker, and incurring subsequent surgery all significantly increased the odds of reporting poorer clinical outcomes at 6 years.

CONCLUSION

Meniscal and chondral pathology at the time of revision ACL reconstruction has continued significant detrimental effects on patient-reported outcomes at 6 years after revision surgery.

Revision Anterior Cruciate Ligament Reconstruction Using Bone-Patellar Tendon-Bone Graft Combined With Modified Lemaire Technique Versus Hamstring Graft Combined With Anterolateral Ligament Reconstruction: A Clinical Comparative Matched Study With a Mean Follow-up of 5 Years From The SANTI Study Group

BACKGROUND

Additional lateral extra-articular tenodesis (LET) has recently been correlated with improved clinical outcomes and reduced failure rates in revision anterior cruciate ligament (ACL) reconstruction (ACLR). However, no data are available on clinical outcomes and reoperation after revision ACLR using different LET procedures.

PURPOSE

To compare the clinical outcomes of ACL + anterolateral ligament (ALL) reconstruction using hamstring tendon graft (HT-ALL) and a bone-patellar tendon-bone (BPTB) graft + modified Lemaire tenodesis procedure (BPTB-Lemaire) in the setting of revision ACLR and to determine whether ALL reconstruction is associated with an increased rate of adverse outcomes when compared with a modified Lemaire tenodesis procedure.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Descriptive data and clinical outcomes were prospectively collected from patients who underwent revision ACLR with LET between 2009 and 2018 with a minimum follow-up of 2 years. Patients with an HT autograft combined with ALL reconstruction (HT-ALL group) were matched in a 1:1 propensity ratio to patients with a BPTB autograft combined with a modified Lemaire LET procedure (BPTB-Lemaire group). The evaluated parameters included complications and reoperations; knee laxity tests; return to sports; and various scores, including the Lysholm knee score, Tegner activity scale, Anterior Cruciate Ligament Return to Sport After Injury scale, Marx activity rating scale, International Knee Documentation Committee subjective knee evaluation form, and Knee injury and Osteoarthritis Outcome Score.

RESULTS

In total, 36 matched pairs were included in the analysis. The mean follow-up durations for the BPTB-Lemaire and HT-ALL groups were 56 ± 35 and 57 ± 23 months, respectively (P = .91). No significant differences were found in graft rupture rate (HT-ALL, 0%; BPTB-Lemaire, 11.1%; P = .13) or reoperations (HT-ALL, 8.3%; BPTB-Lemaire, 22.2%; P = .23). No specific complications with regard to LET were noted in either group. Additionally, there were no significant differences in knee laxity parameters, return to sports, or clinical scores between the groups at the final follow-up, except for the Tegner activity scale score (HT-ALL, 6.4; BPTB-Lemaire, 7.3; P = .03). HT-ALL was associated with a shorter surgical time (41.4 vs 59.8 minutes; P < .0001).

CONCLUSION

HT-ALL was at least equivalent, in terms of clinical outcomes, to the more commonly performed procedure, BPTB-Lemaire. Performing ALL reconstruction in the setting of revision ACLR is therefore safe and effective.

Revision Anterior Cruciate Ligament Reconstruction after Surgical Management of Multiligament Knee Injury

The purpose of this study is to determine factors associated with the need for revision anterior cruciate ligament reconstruction (ACLR) after multiligament knee injury (MLKI) and to report outcomes for patients undergoing revision ACLR after MLKI. This involves a retrospective review of 231 MLKIs in 225 patients treated over a 12-year period, with institutional review board approval. Patients with two or more injured knee ligaments requiring surgical reconstruction, including the ACL, were included for analyses. Overall, 231 knees with MLKIs underwent ACLR, with 10% (n = 24) requiring revision ACLR. There were no significant differences in age, sex, tobacco use, diabetes, or body mass index between cohorts requiring or not requiring revision ACLR. However, patients requiring revision ACLR had significantly longer follow-up duration (55.1 vs. 37.4 months, p = 0.004), more ligament reconstructions/repairs (mean 3.0 vs. 1.7, p < 0.001), more nonligament surgeries (mean 2.2 vs. 0.7, p = 0.002), more total surgeries (mean 5.3 vs. 2.4, p < 0.001), and more graft reconstructions (mean 4.7 vs. 2.7, p < 0.001). Patients in both groups had similar return to work (p = 0.12) and activity (p = 0.91) levels at final follow-up. Patients who had revision ACLR took significantly longer to return to work at their highest level (18 vs. 12 months, p = 0.036), but similar time to return to their highest level of activity (p = 0.33). Range of motion (134 vs. 127 degrees, p = 0.14), pain severity (2.2 vs. 1.7, p = 0.24), and Lysholm's scores (86.3 vs. 90.0, p = 0.24) at final follow-up were similar between groups. Patients requiring revision ACLR in the setting of a MLKI had more overall concurrent surgeries and other ligament reconstructions, but had similar final outcome scores to those who did not require revision surgery. Revision ligament surgery can be associated with increased pain, stiffness, and decrease patient outcomes. Revision surgery is often necessary after multiligament knee reconstructions, but patients requiring ACLR in the setting of a MLKI have good overall outcomes, with patients requiring revision ACLR at a rate of 10%.

Association Between Graft Choice and 6-Year Outcomes of Revision Anterior Cruciate Ligament Reconstruction in the MARS Cohort

BACKGROUND

Although graft choice may be limited in the revision setting based on previously used grafts, most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome.

HYPOTHESIS

In the ACL revision setting, there would be no difference between autograft and allograft in rerupture rate and patient-reported outcomes (PROs) at 6-year follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients who had revision surgery were identified and prospectively enrolled in this cohort study by 83 surgeons over 52 sites. Data collected included baseline characteristics, surgical technique and pathology, and a series of validated PRO measures. Patients were followed up at 6 years and asked to complete the identical set of PRO instruments. Incidence of additional surgery and reoperation because of graft failure were also recorded. Multivariable regression models were used to determine the predictors (risk factors) of PROs, graft rerupture, and reoperation at 6 years after revision surgery.

RESULTS

A total of 1234 patients including 716 (58%) men were enrolled. A total of 325 (26%) underwent revision using a bone-patellar tendon-bone (BTB) autograft; 251 (20%), soft tissue autograft; 289 (23%), BTB allograft; 302 (25%), soft tissue allograft; and 67 (5%), other graft. Questionnaires and telephone follow-up for subsequent surgery information were obtained for 809 (66%) patients, while telephone follow-up was only obtained for an additional 128 patients for the total follow-up on 949 (77%) patients. Graft choice was a significant predictor of 6-year Marx Activity Rating Scale scores (P = .024). Specifically, patients who received a BTB autograft for revision reconstruction had higher activity levels than did patients who received a BTB allograft (odds ratio [OR], 1.92; 95% CI, 1.25-2.94). Graft rerupture was reported in 5.8% (55/949) of patients by their 6-year follow-up: 3.5% (16/455) of patients with autografts and 8.4% (37/441) of patients with allografts. Use of a BTB autograft for revision resulted in patients being 4.2 times less likely to sustain a subsequent graft rupture than if a BTB allograft were utilized (P = .011; 95% CI, 1.56-11.27). No significant differences were found in graft rerupture rates between BTB autograft and soft tissue autografts (P = .87) or between BTB autografts and soft tissue allografts (P = .36). Use of an autograft was found to be a significant predictor of having fewer reoperations within 6 years compared with using an allograft (P = .010; OR, 0.56; 95% CI, 0.36-0.87).

CONCLUSION

BTB and soft tissue autografts had a decreased risk in graft rerupture compared with BTB allografts. BTB autografts were associated with higher activity level than were BTB allografts at 6 years after revision reconstruction. Surgeons and patients should consider this information when choosing a graft for revision ACL reconstruction.

Outcome After Anterior Cruciate Ligament Revision

PURPOSE OF REVIEW

To describe the current literature related to anterior cruciate ligament (ACL) revision in terms of surgical aspects, graft choices, concomitant injuries, patient-reported outcome, return to sport, and objective measurement outcome.

RECENT FINDINGS

An ACL rupture is a common knee injury, and the number of primary ACL reconstructions is increasing, implying a subsequent increase of ACL revisions in the future. It is widely accepted that an ACL revision is surgically challenging with a myriad of graft options to choose from. In many cases, simultaneous injuries to the index limb including meniscal and chondral lesions, respectively, are observed in the setting of a secondary ACL injury. Furthermore, the general understanding is that an ACL revision results in inferior outcome compared with a primary ACL reconstruction. Surgical treatment of an ACL revision can be performed as one-stage or two-stage procedure depending on, for example, the presence of limb malalignments, concomitant injuries, and tunnel widening. Nonirradiated allografts and autologous patella tendon, hamstring tendon, and quadriceps tendon are feasible options for ACL revision. Concomitant injuries to the affected knee such as intraarticular chondral lesions are more common in the setting of an ACL revision compared with primary ACL reconstruction while a lower presence of concomitant meniscal pathology is reported at ACL revision. Patients undergoing ACL revision have lower clinical and patient-reported outcome and lower rates of return to sport when compared with primary ACL surgery cases. However, long-term follow-ups with large study cohorts evaluating outcome of ACL revision are limited. Further research is needed to confirm the present findings of this review.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Meta-analysis of Level II studies, Level II.

What Is the Mid-term Failure Rate of Revision ACL Reconstruction? A Systematic Review

BACKGROUND

When anterior cruciate ligament (ACL) reconstruction fails, a revision procedure may be performed to improve knee function, correct instability, and allow return to activities. The results of revision ACL reconstruction have been reported to produce good but inferior patient-reported and objective outcomes compared with primary ACL reconstruction, but the degree to which this is the case varies widely among published studies and may be influenced by heterogeneity of patients, techniques, and endpoints assessed. For those reasons, a systematic review may provide important insights.

QUESTIONS/PURPOSES

In a systematic review, we asked: (1) What is the proportion of revision ACL reconstruction cumulative failures defined as rerupture or objective failure using prespecified clinical criteria at mean followup of at least 5 years? (2) What are the most common complications of revision ACL reconstruction?

METHODS

A systematic review was performed by searching PubMed/Medline, EMBASE, and CENTRAL. We included studies that reported the clinical evaluation of revision ACL reconstruction with Lachman test, pivot shift test, side-to-side difference with KT-1000/2000 arthrometer, and with a mean followup of at least 5 years. We excluded studies that incompletely reported these outcomes, that reported only reruptures, or that were not in the English language. Extracted data included the number of graft reruptures and objective clinical failure, defined as a knee that met one of the following endpoints: Lachman test Grade II to III, pivot shift Grade II to III, KT-1000/2000 > 5-mm difference, or International Knee Documentation Committee Grade C or D. For each study, we determined the proportion of patients who had experienced a rupture of the revision ACL graft as well as the proportion of patients who met one or more of our clinical failure endpoints. Those proportions were summed for each study to generate a percentage of patients who met our definition of cumulative failure. Complications and reoperations were recorded but not pooled as a result of inconsistency of reporting and heterogeneity of populations across the included studies. Of the 663 screened studies, 15 articles were included in the systematic review. Because one study reported two separate groups of patients with different treatments, 16 case series were considered in the evaluation.

RESULTS

The proportion of reruptures (range, 0%-25%) was > 5% in only four of 16 series and > 10% in only one of them. The objective clinical failures (range, 0%-82%) was > 5% in 15 of 16 series and > 10% in 12 of them. The proportion exceeded 20% in five of 16 series. The cumulative failures (range, 0%-83%) was > 5% in all except one series and > 10% in 12 of 16 series; five series had a cumulative failure proportion > 20%. The most frequent complications were knee stiffness and anterior knee pain, whereas reoperations were primarily débridement and meniscectomies.

CONCLUSIONS

Considering rerupture alone as a failure endpoint in patients who have undergone revision ACL reconstruction likely underestimates the real failure rate, because the percentage of failures noticeably increases when objective criteria are also considered. Whether patient-reported and subjective scores evaluating knee function, level of activity, satisfaction, and pain might also contribute to the definition of failure may be the focus of future studies.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Does the type of graft affect the outcome of revision anterior cruciate ligament reconstruction? a meta-analysis of 32 studies

AIMS

Our aim was to perform a meta-analysis of the outcomes of revision anterior cruciate ligament (ACL) reconstruction, comparing the use of different types of graft.

MATERIALS AND METHODS

A search was performed of Medline and Pubmed using the terms "Anterior Cruciate Ligament" and "ACL" combined with "revision", "re-operation" and "failure". Only studies that reported the outcome at a minimum follow-up of two years were included. Two authors reviewed the papers, and outcomes were subdivided into autograft and allograft. Autograft was subdivided into hamstring (HS) and bone-patellar tendon-bone (BPTB). Subjective and objective outcome measures were analysed and odds ratios with confidence intervals were calculated.

RESULTS

A total of 32 studies met the inclusion criteria. Five studies used HS autografts, eight reported using BPTB autografts, two used quadriceps tendon autografts and eight used various types. Seven studies reported using allografts, while the two remaining used both BPTB autografts and allografts. Overall, 1192 patients with a mean age of 28.7 years (22.5 to 39) and a mean follow-up of 5.4 years (2.0 to 9.6) were treated with autografts, while 269 patients with a mean age of 28.4 years (25 to 34.6) and a mean follow-up of 4.0 years (2.3 to 6.0) were treated with allografts. Regarding allografts, irradiation with 2.5 mrad was used in two studies while the graft was not irradiated in the seven remaining studies. Reconstructions following the use of autografts had better outcomes than those using allograft with respect to laxity, measured by KT-1000/2000 (MEDmetric Corporation) and the rates of complications and re-operations. Those following the use of allografts had better mean Lysholm and Tegner activity scores compared with autografts. If irradiated allografts were excluded from the analysis, outcomes no longer differed between the use of autografts and allografts. Comparing the types of autograft, all outcomes were similar except for HS grafts which had better International Knee Documentation Committee scores compared with BPTB grafts.

CONCLUSION

Autografts had better outcomes than allografts in revision ACL reconstruction, with lower post-operative laxity and rates of complications and re-operations. However, after excluding irradiated allografts, outcomes were similar between autografts and allografts. Overall, the choice of graft at revision ACL reconstruction should be on an individual basis considering, for instance, the preferred technique of the surgeon, whether a combined reconstruction is required, the type of graft that was previously used, whether the tunnels are enlarged and the availability of allograft. Cite this article: Bone Joint J 2017;99-B:714-23.

Magnetic resonance imaging after anterior cruciate ligament reconstruction: A practical guide

Anterior cruciate ligament (ACL) reconstruction is one of the most common orthopedic procedures performed worldwide. In this regard, magnetic resonance imaging (MRI) represents a useful pre-operative tool to confirm a disruption of the ACL and to assess for potential associated injuries. However, MRI is also valuable post-operatively, as it is able to identify, in a non-invasive way, a number of aspects and situations that could suggest potential problems to clinicians. Graft signal and integrity, correct tunnel placement, tunnel widening, and problems with fixation devices or the donor site could all compromise the surgical outcomes and potentially predict the failure of the ACL reconstruction. Furthermore, several anatomical features of the knee could be associated to worst outcomes or higher risk of failure. This review provides a practical guide for the clinician to evaluate the post-surgical ACL through MRI, and to analyze all the parameters and features directly or indirectly related to ACL reconstruction, in order to assess for normal or pathologic conditions.

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.

Healing of donor site in bone-tendon-bone ACL reconstruction accelerated with plasma rich in growth factors: a randomized clinical trial

PURPOSE

To determine whether the use of plasma rich in growth factors accelerates healing of the donor site in bone-tendon-bone anterior cruciate ligament (ACL) reconstruction (patellar graft). The use of the patellar graft presents post-operative problems such as anterior knee pain, which limits its use and leads to preference being taken for alternative grafts.

METHODS

A double-blind, randomized, clinical trial was performed comparing two groups of patients who underwent ACL reconstruction using patellar tendon graft and comparing the use of plasma rich in growth factors at the donor site after graft harvest in terms of local regeneration by ultrasound assessment.

RESULTS

The plasma rich in growth factors group shows earlier donor site regeneration in comparison with the control group (2 months earlier), with significant differences in the first 4 months of the follow-up.

CONCLUSION

The application of plasma rich in growth factors shows accelerated tissue regeneration processes with respect to the control group. This fact, together with the previously published with similar conclusions, can create a knowledge basis in order to set out new recovery guidelines following ACL reconstruction.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

Investigating tendon mineralisation in the avian hindlimb: a model for tendon ageing, injury and disease

Mineralisation of the tendon tissue has been described in various models of injury, ageing and disease. Often resulting in painful and debilitating conditions, the processes underlying this mechanism are poorly understood. To elucidate the progression from healthy tendon to mineralised tendon, an appropriate model is required. In this study, we describe the spontaneous and non-pathological ossification and calcification of tendons of the hindlimb of the domestic chicken (Gallus gallus domesticus). The appearance of the ossified avian tendon has been described previously, although there have been no studies investigating the developmental processes and underlying mechanisms leading to the ossified avian tendon. The tissue and cells from three tendons - the ossifying extensor and flexor digitorum longus tendons and the non-ossifying Achilles tendon - were analysed for markers of ageing and mineralisation using histology, immunohistochemistry, cytochemistry and molecular analysis. Histologically, the adult tissue showed a loss of healthy tendon crimp morphology as well as markers of calcium deposits and mineralisation. The tissue showed a lowered expression of collagens inherent to the tendon extracellular matrix and presented proteins expressed by bone. The cells from the ossified tendons showed a chondrogenic and osteogenic phenotype as well as tenogenic phenotype and expressed the same markers of ossification and calcification as the tissue. A molecular analysis of the gene expression of the cells confirmed these results. Tendon ossification within the ossified avian tendon seems to be the result of an endochondral process driven by its cells, although the roles of the different cell populations have yet to be elucidated. Understanding the role of the tenocyte within this tissue and the process behind tendon ossification may help us prevent or treat ossification that occurs in injured, ageing or diseased tendon.

The reharvested patellar tendon has the potential for ligamentization when used for anterior cruciate ligament revision surgery

PURPOSE

The aim of the present study was to make an in-depth clinical, radiographical, and histological evaluation of patients who underwent anterior cruciate ligament (ACL) revision surgery with reharvested central third patellar tendon autograft.

METHODS

Four patients (two women and two men) underwent ACL revision surgery with reharvested patellar tendon autograft 71 (66-120) months after the primary reconstruction. The patients were followed prospectively and underwent a clinical examination and magnetic resonance imaging (MRI) at two and 10 years. Furthermore, they underwent a second-look arthroscopy involving a biopsy procedure from the reconstructed ACL 3 years after revision surgery.

RESULTS

The clinical results were poor both at two and 10 years, but the knees were stable and had a firm endpoint in all four patients in the Lachman test. At the second-look arthroscopy, the graft appeared macroscopically normal in all four patients. Histologically two patients had a normal or close to normal appearance of the reconstructed ACL with no or slight increase in cellularity and vascularity. Two patients had a marked increase in cellularity and vascularity, and the findings revealed that ligamentization was present in all four patients.

CONCLUSIONS

The clinical outcome 10 years after ACL revision surgery was poor in these four patients. In contrast, the reharvested patellar tendon appeared close to normal on MRI, and the second-look arthroscopy with the concomitant histological findings revealed that the grafts were viable 3 years after revision. Therefore, the reharvested patellar tendon seems to have the potential for ligamentization when used for ACL revision surgery.

LEVEL OF EVIDENCE

Case series, Level IV.

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.

Ectopic chondro-ossification and erroneous extracellular matrix deposition in a tendon window injury model

The acquisition of chondro-osteogenic phenotypes and erroneous matrix deposition may account for poor tissue quality after acute tendon injury. We investigated the presence of chondrocyte phenotype, ossification, and the changes in the expression of major collagens and proteoglycans in the window wound in a rat patellar tendon window injury model using histology, von Kossa staining and immunohistochemistry of Sox 9, major collagens, and proteoglycans. Our results showed that the repair tissue did not restore to normal after acute injury. Ectopic chondrogenesis was observed in 33% of samples inside wound at week 4 while ectopic ossification surrounded by chondrocyte-like cells were observed in the window wound in 50% of samples at week 12. There was sustained expression of biglycan and reduced expression of aggrecan and decorin in the tendon matrix in the repair tissue. The erroneous deposition of extracellular matrix and ectopic chondro-ossification in the repair tissue, both might influence each other, might account for the poor tissue quality after acute injury. Higher expression of biglycan and aggrecan were observed in the ectopic chondro-ossification sites in the repair tissue, suggesting that they might have roles in ectopic chondro-osteogenesis.

Osteoarthritic changes after anterior cruciate ligament reconstruction using bone-patellar tendon-bone or hamstring tendon autografts: a retrospective, 7-year radiographic and clinical follow-up study

PURPOSE

This study was undertaken to evaluate the long-term radiographic appearance and clinical outcome after anterior cruciate ligament (ACL) reconstruction by use of either bone-patellar tendon-bone (BPTB) or hamstring tendon (HT) autografts and to evaluate how associated meniscal injuries affect the prevalence of osteoarthritis (OA).

METHODS

ACL reconstruction was performed in 124 consecutive patients. Of these patients, 113 (91%) (72 BPTB and 41 HT) returned for a follow-up examination at a median of 86 months (range, 67 to 111 months) after reconstruction. The patients underwent standard weight-bearing radiographic examinations and clinical evaluation.

RESULTS

The radiographic assessments showed no significant differences between the graft types in terms of OA classified according to the Ahlbäck and Fairbank rating systems. Overall, 23% of the patients had degenerative changes according to the Ahlbäck system, and 74% had degenerative changes according to the Fairbank system. Associated meniscal injuries increased the prevalence of OA. Clinically, no significant differences were found between the graft types in terms of the Tegner activity test, 1-leg hop test, International Knee Documentation Committee evaluation system, disturbed area of sensitivity, manual Lachman test, KT-1000 laxity test (MEDmetric, San Diego, CA), and knee-walking test. The Lysholm score (P = .02) and knee-walking ability (P = .02) were significantly better in the HT group.

CONCLUSIONS

At a median of 7 years after ACL reconstruction with either BPTB or HT autografts, the prevalence of OA as seen on standard weight-bearing radiographs and the clinical outcome were comparable. The presence of meniscal injuries increased the prevalence of OA.

LEVEL OF EVIDENCE

Level III, therapeutic, retrospective comparative study.

A histological and ultrastructural evaluation of the patellar tendon 10 years after reharvesting its central third

PURPOSE

This study was undertaken to evaluate the histologic and ultrastructural characteristics of the patellar tendon 10 years after reharvesting its central third.

HYPOTHESIS

In the long term, after its central third is reharvested, the patellar tendon does not regain a normal histological and ultrastructural appearance.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Twelve consecutive patients (4 women, 8 men) who underwent anterior cruciate ligament revision surgery using reharvested ipsilateral patellar tendon autografts were included in the study. Percutaneous biopsy samples were obtained from the central and lateral parts of the patellar tendon under ultrasonographic guidance at a median of 116 months (range, 102-127 months) after the revision procedure. Eleven biopsy specimens from asymptomatic patellar tendons obtained from open anterior cruciate ligament reconstructions served as controls. The histologic characteristics and the presence of glycosaminoglycans were assessed using a light microscope, and the ultrastructure was assessed using a transmission electron microscope.

RESULTS

The histological evaluation revealed deterioration in fiber structure, increased cellularity, and increased vascularity in both the central and peripheral parts of the reharvested patellar tendon specimens compared with normal tendon specimens. No difference in the amount of glycosaminoglycans was seen in specimens from either part of the reharvested patellar tendons and the control specimens. The ultrastructural evaluation revealed that all the control specimens had a normal morphologic appearance and a compact extracellular matrix with regularly oriented collagen fibrils. Furthermore, in the control specimens, the fibril diameter was heterogeneous, with all fibril size classes present. Specimens from the central and the lateral part of the reharvested tendon displayed pathological cell appearance and a more heterogeneous extracellular matrix. The lateral specimens from the reharvested tendons also displayed all fibril size classes but with a more homogeneous distribution. In the central specimens, the largest fibril size class was absent.

CONCLUSION

Ten years after its central third was reharvested for anterior cruciate ligament revision surgery, the patellar tendon had not normalized in terms of its histological and ultrastructural appearance.