Allograft anterior cruciate ligament reconstruction in patients over 40 years of age

Outcomes of Anterior Cruciate Ligament Reconstruction in Patients Older Than 50 Years and Younger Than 30 Years

Background:

Few studies have compared the outcomes of anterior cruciate ligament (ACL) reconstruction between older patients and younger patients.

Purpose:

To evaluate the clinical and functional outcomes of ACL reconstruction with autologous hamstring tendon in patients >50 years and <30 years. It was hypothesized that the outcomes would be comparable between these age groups.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients >50 years (older group) or <30 years (younger group) who underwent ACL reconstruction surgery with autologous hamstring tendon between 2012 and 2015 at the authors’ hospital were retrospectively enrolled in this study. All patients had a minimum of 2 years of follow-up. Intraoperative findings, including cartilage and meniscal injury, were recorded, and clinical and functional outcomes were evaluated using the International Knee Documentation Committee (IKDC), Lysholm, and Tegner activity scores. We used the paired-samples t test for statistical analysis between the 2 age groups.

Results:

A total of 67 patients and 459 patients were included in the older and younger groups, respectively. Both groups achieved significant preoperative to postoperative improvement in IKDC (older group, from 41.4 to 88.9; younger group, from 49 to 91.2), Lysholm (older group, from 49.8 to 86.1; younger group, from 50.2 to 91.8), and Tegner (older group, from 2.7 to 4.4; younger group, from 4.6 to 6.9) (P < .05 for all) scores. The change in Tegner score from preinjury to postoperatively was not statistically significant in the older group (from 4.5 to 4.4; P = .471), although it was significant in the younger group (from 7.5 to 6.9; P < .05). No between-group differences were noted in preoperative or postoperative IKDC or Lysholm scores. Both age groups reached a high rate of return to sports activity, and no major complications or ACL retears were noted in either group.

Conclusion:

Comparable results after ACL reconstruction were achieved in patients >50 years compared with patients <30 years, with a high rate of return to sports activity and a low rate of complications at the 2-year follow-up. The younger group returned to a higher Tegner score, while the older group did not.

Current trends in the anterior cruciate ligament part II: evaluation, surgical technique, prevention, and rehabilitation

Clinical evaluation and management of anterior cruciate ligament (ACL) injury is one of the most widely researched topics in orthopedic sports medicine, giving providers ample data on which to base their practices. The ACL is also the most commonly treated knee ligament. This study reports on current topics and research in clinical management of ACL injury, starting with evaluation, operative versus nonoperative management, and considerations in unique populations. Discussion of graft selection and associated procedures follows. Areas of uncertainty, rehabilitation, and prevention are the final topics before a reflection on the current state of ACL research and clinical management of ACL injury. Level of evidence V.

Comparable clinical and functional outcomes after anterior cruciate ligament reconstruction over and under 40 years of age

PURPOSE

The aim of the present meta-analysis was to update the literature on the outcomes and complications of ACL reconstruction in patients aged 40 years and older. It has been hypothesized that patients older than 40 years of age may have comparable clinical outcomes to those of younger patients.

METHODS

A systematic review of articles from 1996 to 2018 was completed using Pubmed, Medline, Cochrane Reviews, and Google Scholar databases using the keyword terms "anterior cruciate ligament reconstruction" and "middle-aged OR elderly OR over 40 OR age factors." Functional and clinical outcomes (International Knee Documentation Committee, Lysholm and Tegner score and KT-1000 arthrometer), complication and graft failure rate were evaluated.

RESULTS

Eleven articles met inclusion criteria. In total, 306 middle-aged patients and 566 younger patients were included in this study. The mean age of patients > 40 was 49 ± 7 (range 40-75) years with a mean follow-up of 25 ± 9 months (range 12-68). The mean age of younger patients was 26 ± 2.7 (range 15-39) years with a mean post-operative follow-up of 26.7 ± 11.5 months (range 3-64). The results were slightly higher (but no significantly different) towards the younger group in terms of objective IKDC (P = n.s.), Lysholm (P = n.s.) and Tegner (P = n.s.) scores and knee laxity assessment (P = n.s.). Complication rate (P = n.s.) and graft failure (P = n.s.) were low even in this cohort.

CONCLUSIONS

The present meta-analysis shows that patients older than 40 years achieve comparable clinical outcomes to those of younger patients following primary ACL reconstruction. This evidence may push the surgeons toward a more aggressive approach in this specific cohort of patients.

LEVEL OF EVIDENCE

III.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of anterior cruciate ligament injury - Secondary publication

BACKGROUND

This clinical guideline presents recommendations for the management of patients with anterior cruciate ligament (ACL) injury, endorsed by the Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Society of Knee, Arthroscopy and Sports Medicine (JOSKAS).

METHODS

The JOA ACL guideline committee revised the previous guideline based on "Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014", which proposed a desirable method for preparing clinical guidelines in Japan. Furthermore, the importance of "the balance of benefit and harm" was also emphasized. This guideline consists of 21 clinical questions (CQ) and 23 background questions (BQ). For each CQ, outcomes from the literature were collected and evaluated systematically according to the adopted study design.

RESULTS

We evaluated the objectives and results of each study in order to make a decision on the level of evidence so as to integrate the results with our recommendations for each CQ. For BQ, the guideline committee proposed recommendations based on the literature.

CONCLUSIONS

This guideline is intended to be used by physicians, orthopedic surgeons, physical therapists, and athletic trainers managing ACL injuries. We hope that this guideline is useful for appropriate decision-making and improved management of ACL injuries.

Delayed ACL Reconstruction in Patients ≥40 Years of Age Is Associated With Increased Risk of Medial Meniscal Injury at 1 Year

BACKGROUND

Anterior cruciate ligament (ACL) tears in the pediatric and young adult ACL-deficient knee are often associated with meniscal or chondral injury with delayed time to surgery. The incidence of ACL reconstruction performed in patients aged ≥40 years is rising, and it is unclear if delayed surgery in this cohort similarly affects the health of the meniscus and cartilage.

PURPOSE

To evaluate whether delayed reconstruction in a cohort of patients aged ≥40 years is associated with an increased risk of meniscal or chondral injury.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Records of patients aged ≥40 years who underwent primary arthroscopic ACL reconstruction between 2012 and 2016 at an academic hospital were retrospectively reviewed. Patient characteristic data and time to surgery were recorded. Operative reports were analyzed for meniscal and chondral injuries as well as treatment. Patients were grouped according to time to surgery, defined as early (<90 days) or delayed (≥90 days). Logistic regression modeling was used to form associations between elapsed time to surgery and patient characteristics to meniscal and chondral damage. Additionally, risks for meniscal and chondral injury were analyzed at time points of 180 days and 1 year from injury to surgery.

RESULTS

A total of 227 patients met the study criteria: 106 patients underwent early surgery, and 121 underwent delayed surgery. The authors identified 127 medial meniscal tears and 106 lateral meniscal tears. Medial, lateral, and patellofemoral compartment chondral injury was reported in 127, 82, and 130 patients, respectively. Delayed surgery (≥90 days) was not associated with increased risk of medial or lateral meniscal tears or any chondral injury at 90 days. Each year of increased age was associated with an increased odds ratio: 1.09 ( P = .001) for medial meniscal tears, 1.06 ( P = .014) for lateral meniscal tears, 1.10 ( P = .001) for medial compartment chondral injuries, and 1.07 ( P = .007) for patellofemoral compartment chondral injuries. Additionally, each unit of increased body mass index was associated with an increased odds ratio: 1.09 ( P = .039) for medial meniscal tears and 1.14 ( P = .003) for medial compartment cartilage injury. Analysis of 180-day and 1-year time points revealed an increased risk (odds ratio, 3.47; 95% CI, 1.55-7.77; P = .002) for medial meniscal injury when surgery was delayed for >1 year.

CONCLUSION

Delayed ACL reconstruction (≥90 days) among patients aged ≥40 years was not associated with an increased risk of meniscal or chondral injury. Increasing age and body mass index were associated with higher risks of meniscal and chondral injuries in this cohort. Delay in surgery for >1 year was associated with increased risk of medial meniscal tear.

Outcomes and Complication Rates After Primary Anterior Cruciate Ligament Reconstruction Are Similar in Younger and Older Patients

Background:

Until recently, anterior cruciate ligament (ACL) tears in older patients were treated conservatively; however, these patients often experienced significant pain and instability.

Purpose/Hypothesis:

The purpose of this study was to compare the patient-reported outcomes, patient satisfaction, and failure rates of primary ACL reconstruction between a younger (age 20-30 years) and older (age 50-75 years) patient cohort. It was hypothesized that patients in the older cohort could achieve comparable clinical outcomes and retear rates following ACL reconstruction with a bone-tendon-bone autograft or allograft compared with the younger patients.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A retrospective analysis of prospectively collected data was performed. All patients undergoing a primary ACL reconstruction between 2010 and 2014 by a single surgeon were collated. Patients were divided into 2 groups based on age at the time of surgery: a younger cohort (20-30 years) and an older cohort (50-75 years). Patients were excluded if they were outside the desired age intervals; had revision ACL reconstructions; had a previous intra-articular infection in the ipsilateral knee; underwent prior alignment correction procedure, cartilage repair, or transplant procedure; had a concurrent posterior cruciate ligament tear; received meniscal allograft transplant; or had an intra-articular fracture. Subjective outcome scores (Tegner activity scale, Lysholm, International Knee Documentation Committee [IKDC], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], Short Form–12 [SF-12] mental health component summary [MCS], and SF-12 physical component summary [PCS]), retear rate, and rate of secondary arthrofibrosis surgery were documented at a minimum 2-year follow-up and were compared between groups.

Results:

A total of 85 patients met the inclusion criteria for this study: 52 patients (33 males, 19 females) in the younger cohort and 33 patients (14 males, 19 females) in the older cohort. No significant differences were found in any demographic factor except for age. Significant improvement in outcome scores from pre- to postoperative assessments was found in both groups. The younger cohort had significantly lower postoperative WOMAC scores (P = .025). However, no significant differences were found between the younger and older cohorts in postoperative SF-12 PCS (P = .487), SF-12 MCS (P = .900), Lysholm score (P = .660), IKDC score (P = .256), Tegner activity score (P = .420), or patient satisfaction (P = .060). Within the older cohort, increasing age did not correlate with inferior postoperative outcome scores. Furthermore, no retears occurred in either group, and the rates of arthrofibrosis surgery were comparable (12% older cohort vs 13% younger cohort).

Conclusion:

Improved function and satisfaction, comparable to the younger age group, were achieved in patients older than 50 years undergoing ACL reconstruction. Furthermore, low failure rates can be achieved in both younger and older patients undergoing ACL reconstruction.

Acute ACL reconstruction in patients over 40 years of age

PURPOSE

The purpose of this study is to compare the clinical outcome of ACL reconstructions in patients older than 40 years of age to younger subjects. It has been hypothesized that patients older than 40 years of age achieve comparable clinical outcomes following acute ACL reconstruction using a hamstring tendon autograft than younger patients.

METHODS

Patients with an isolated ACL tear without any concomitant injuries and subsequent ACL reconstruction within 48 h from injury were included in this prospective study. According to patients' age, subjects were assigned to two groups: (A) 18-40 years and (B) 40-60 years. Functional outcomes, pain, post-operative radiographs and return to sports were recorded and analysed. The follow-up period was 24 months.

RESULTS

A total of 59 patients were included in the study. Group A consisted of 39 patients (14 women, 25 men; median 27 years), group B of 20 patients (12 women, 8 men; median 45 years) respectively. At final follow-up, the Lysholm score showed no significant difference between group A (median 90; range 68-100) and group B (median 94.5; range 63-100) (n.s.). The final Tegner score showed a significant difference between group A (median 6; range 2-9) and group B (median 5.5; range 3-8) (p < 0.05). The mean VAS pain score was 1.3 (range 0-6) in group A and 1 (range 0-7) in group B, respectively (n.s.). Both groups returned to their pre-injury activity level and did not significantly change their activity in respect of pivoting sports and sports frequency at final follow-up (n.s.). According to the IKDC score, all except one of the patients in group A and all patients in group B had a normal or nearly normal final outcome (n.s.).

CONCLUSION

Patients older than 40 years of age achieve comparable clinical outcomes following acute ACL reconstruction using a hamstring tendon autograft than younger patients.

LEVEL OF EVIDENCE

Cohort study, Level III.

Results After Anterior Cruciate Ligament Reconstruction in Patients Older Than 40 Years: How Do They Compare With Younger Patients? A Systematic Review and Comparison With Younger Populations

Context:

Anterior cruciate ligament (ACL) reconstruction in older patients is a controversial topic among orthopaedic surgeons.

Objective:

To determine the outcomes, failure, and morbidity associated with ACL reconstruction in patients older than 40 years and to compare it with nonoperative treatment as well as results of ACL reconstruction in a younger patient population.

Data Sources:

A systematic review of the literature from 1970 to 2015 was conducted utilizing MEDLINE, CINAHL, and the Cochrane Central Register databases using PRISMA guidelines.

Study Selection:

Inclusion criteria were studies with longer than 2-year follow-up of primary ACL reconstruction and minimum age of patients older than 40 years, inclusive of any graft type or source and of any concomitant meniscal pathology.

Study Design:

Systematic review.

Level of Evidence:

Level 4.

Data Extraction:

Two independent reviewers collected demographic, preoperative, intraoperative, and postoperative data.

Results:

Twelve studies with a total of 452 patients were included. The mean patient age was 47.8 years (range, 40-66 years) with a mean follow-up of 53.3 months (minimum, 24 months). Lysholm scores improved from 53.9 to 90.5 in the 11 operative studies. The only nonoperative study reported a mean Lysholm score of 82 after rehabilitation. International Knee Documentation Committee (IKDC) scores of A or B were found in 81%. Tegner activity scores averaged 4.7 preinjury, fell to 2.9 preoperatively, and returned to 4.7 postoperatively. The reported failure rate was 2.3%. There were few complications, and failure rate was similar in younger patients.

Conclusion:

The data confirm that ACL reconstruction can be recommended to patients older than 40 years who wish to maintain an active lifestyle or have symptomatic instability with daily activities. Patient-based outcomes scores were better in the operative studies compared with the single nonoperative study in this patient population.

Long-term Outcomes After Anterior Cruciate Ligament Reconstruction in Patients 60 Years and Older

Background:

Studies evaluating the benefit of surgical reconstruction of the anterior cruciate ligament (ACL) in middle-aged patients have shown promising results, but study populations were limited primarily to patients who were 40 to 60 years old. Some authors have suggested that surgery may benefit these older patients.

Hypothesis:

Patients aged ≥60 years with functional instability after ACL injury would benefit from ACL reconstruction.

Study Design:

Case series; Level of evidence, 4.

Methods:

Medical records from 1984 through 2010 were searched for patients aged ≥60 years who had undergone primary arthroscopic ACL reconstruction at a single institution. Fifteen patients (15 knees) were identified as meeting the above criteria. All patients were contacted for a telephone interview, and they completed Short Form–36 and modified Cincinnati Knee Score forms. One patient was deceased, and 1 had undergone revision to total knee arthroplasty. Among the remaining 13 patients, the mean age at surgery was 63.5 years (range, 60-73 years), and the mean patient age at the time of follow-up was 73 years (range, 65-85 years). Preoperative radiographs showed no obvious evidence of arthritis in 10 (77%) of the 13 patients; small osteophytes without loss of joint space were seen in 3 (23%) patients. The mean length of follow up was 115.7 months (range, 53-193 months).

Results:

At their last clinic visits, all 13 patients had regained full range of motion and returned to sports or exercise, such as tennis, golf, gym exercise, and yoga. Twelve patients reported no joint laxity.

Conclusion:

Patients aged ≥60 years with symptomatic instability from ACL injury can have good to excellent subjective outcomes with surgical reconstruction.

Clinical Relevance:

Physicians who treat active patients older than 60 years should not exclude ACL reconstruction based on the patient’s age alone.

Outcomes after ACL reconstruction with focus on older patients: results from The Swedish National Anterior Cruciate Ligament Register

PURPOSE

To investigate and analyse outcomes of patients over the age of 40 who had undergone anterior cruciate ligament (ACL) reconstruction and to compare them to their younger counterparts. We analysed patient-reported outcomes measured using the knee injury and osteoarthritis outcome score (KOOS) as well as aetiology of injury, concomitant intra-articular injuries and time from injury to surgery.

METHODS

Data were extracted from the Swedish National Knee Ligament Register during the period of 2005 through 2012. The following data were extracted and analysed: patient age, gender, activity at the time of injury, time between injury and reconstruction, concomitant intra-articular injuries, graft size used for reconstruction and KOOS measured pre-operatively as well as 1, 2 and 5 years post-operatively. The cohort was stratified into age groups of 0-19, 20-29, 30-39 and ≥ 40 years of age.

RESULTS

Pivoting sports were dominating as the cause of ACL injury in the younger age groups (up to 39 years). Alpine skiing and other non-specified activities were the most common causes in the older age group (≥ 40 years). Pre-operative KOOS was significantly lower in older age groups (p < 0.01). Post-operative KOOS regarding all subscales was significantly better in the older age group. The improvement in KOOS was significant with increasing age (p < 0.01). Older patients exhibited the greatest improvement in KOOS for all subscales at 1, 2 and 5 years post-operative follow-ups compared with pre-operative values (p < 0.01). Older patients had more cartilage injuries pre-operatively compared with younger patients. The same trend was observed in the older group for meniscus injury with and without cartilage injuries. The diameter of the graft used for ACL reconstruction was significantly larger in the older age groups and largest in the age group ≥ 40 years (p < 0.01). Older patients waited significantly longer for surgery after the ACL injury (p < 0.01).

CONCLUSION

In the older age groups, patients reported lower pre-operative KOOS compared with their younger counterparts. At follow-up, KOOS was similar in all age groups. From these results, we can therefore conclude that our hypothesis confirmed that optimal surgical results can in fact be achieved even in older patients.

Effectiveness of low-profile supplemental fixation in anterior cruciate ligament reconstructions with decreased bone mineral density

PURPOSE

The purpose of this study was to compare anterior cruciate ligament (ACL) fixation using a bioabsorbable interference screw (BIS) and a supplemental low-profile suture anchor (PushLock 4.5-mm polyetheretherketone anchor; Arthrex, Naples, FL) with a standard BIS fixation to determine if fixation methods were dependent on tibial bone mineral density (BMD).

METHODS

Ten matched pairs of fresh-frozen human female knee specimens (20 total) were harvested with specimen ages ranging from 40 to 65 years. The BMD for each specimen was determined with a dual-energy x-ray absorptiometry scanner. The specimens were divided into 2 groups, 1 with a BIS and the other with a BIS plus a PushLock. Tibial-sided ACL fixation with hamstring tendon grafts was performed on all the specimens. Then, load to failure and stiffness were biomechanically tested.

RESULTS

The BIS-plus-PushLock specimens had a significantly higher mean yield load compared with specimens with the BIS alone (702 N v 517 N, P = .047). However, in samples with lower bone density, there was no statistically significant difference in failure loads between fixation techniques (P = .8566 at BMD of 0.5 g/cm(2)). As the bone density of the samples increased, the failure loads increased for both techniques (P < .0001 for PushLock and P = .0057 for BIS). This BMD-associated increase was greater for the PushLock (P = .0148), resulting in a statistically significant difference in failure load at the upper range tested (P = .0293 at BMD of 0.9 g/cm(2)).

CONCLUSIONS

Supplemental fixation of ACL reconstructions with a PushLock is beneficial in persons with a normal BMD of the proximal tibia, but at a lower BMD, there was no difference in our study.

CLINICAL RELEVANCE

Individuals with normal BMDs may benefit from this supplemental fixation. However, caution should be used in postmenopausal women or individuals with chronic ACL injuries when using this fixation strategy.

ACL reconstruction in patients aged 40 years and older: a systematic review and introduction of a new methodology score for ACL studies

BACKGROUND

Treatment of the anterior cruciate ligament (ACL)-deficient knee in older patients remains a core debate.

PURPOSE

To perform a systematic review of studies that assessed outcomes in patients aged 40 years and older treated with ACL reconstruction and to provide a new methodological scoring system that is directed at critical assessment of studies evaluating ACL surgical outcomes: the ACL Methodology Score (AMS).

STUDY DESIGN

Systematic review.

METHODS

A comprehensive literature search was performed from 1995 to 2012 using MEDLINE, EMBASE, and Scopus. Inclusion criteria for studies were primary ACL injury, patient age of 40 years and older, and mean follow-up of at least 21 months after reconstruction. Nineteen studies met the inclusion criteria from the 371 abstracts from MEDLINE and 880 abstracts from Scopus. Clinical outcomes (International Knee Documentation Committee [IKDC], Lysholm, and Tegner activity scores), joint stability measures (Lachman test, pivot-shift test, and instrumented knee arthrometer assessment), graft type, complications, and reported chondral or meniscal injury were evaluated in this review. A new methodology scoring system was developed to be specific at critically analyzing ACL outcome studies and used to examine each study design.

RESULTS

Nineteen studies describing 627 patients (632 knees; mean age, 49.0 years; range, 42.6-60.0 years) were included in the review. The mean time to surgery was 32.0 months (range, 2.9-88.0 months), with a mean follow-up of 40.2 months (range, 21.0-114.0 months). The IKDC, Lysholm, and Tegner scores and knee laxity assessment indicated favorable results in the studies that reported these outcomes. Patients did not demonstrate a significant difference between graft types and functional outcome scores or stability assessment. The mean AMS was 43.9 ± 7.2 (range, 33.5-57.5). The level of evidence rating did not positively correlate with the AMS, which suggests that the new AMS system may be able to detect errors in methodology or reporting that may not be taken into account by the classic level of evidence rating.

CONCLUSION

Patients aged 40 years and older with an ACL injury can have satisfactory outcomes after reconstruction. However, the quality of currently available data is still limited, such that further well-designed studies are needed to determine long-term efficacy and to better inform our patients with regard to expected outcomes.

Anterior cruciate ligament reconstruction in patients aged > 40 years: a case-control study

PURPOSE

To determine the outcomes of isolated anterior cruciate ligament (ACL) reconstruction in physically active patients aged > 40 years, and to compare these results with those of a younger patient cohort who underwent the same procedure.

METHODS

A retrospective review was performed on all patients aged > 40 years who underwent ACL reconstruction between 2000 and 2008. A consecutive series of patients aged ≤ 25 years who underwent the same procedure during this same time period were selected as a control group. Age, sex, graft type, concomitant injuries, complications, and a validated outcome measure (Lysholm Knee Scoring Scale) were assessed at final follow-up.

RESULTS

Forty-six patients (average age, 44.9 years; 28 men, 18 women) in the older group were identified and compared with 48 patients (average age, 21 years; 23 men, 25 women) in the younger group, with an average follow-up period of 5.4 and 5.1 years, respectively. There was no statistically significant difference between the groups in terms of associated injuries. The older group had a higher degree of cartilage degeneration (P = 0.0001). Lysholm scores averaged 90.3 in the older cohort compared with 88.7 in the younger cohort, with no statistical difference between groups.

CONCLUSION

The older patients had outcomes comparable with the younger patients. Age alone should not exclude ACL-deficient patients from undergoing reconstructive surgery.

Tibialis anterior or posterior allograft anterior cruciate ligament reconstruction versus hamstring autograft reconstruction: an economic analysis in a hospital-based outpatient setting

PURPOSE

To analyze and compare the direct costs, reimbursement rates, gross contribution margins, and operating room and recovery room times for anterior cruciate ligament (ACL) reconstructions with the use of soft-tissue allografts and autografts. We aimed to determine the financial impact of using allograft tissue for ACL reconstruction in a hospital-based outpatient setting.

METHODS

Financial data from the facility billing database and operating room (OR) reports from the electronic medical record were queried to identify all patients undergoing arthroscopic ACL reconstruction during a 12-month period. A subset of patients who had isolated ACL reconstruction with or without simple meniscectomy or chondral debridement was identified as the study group. We compared 46 ACL reconstructions using tibialis anterior or posterior allografts and 50 ACL reconstructions using hamstring autografts. Facility direct cost, reimbursement rates, gross contribution margin, OR times, and other variables were compared.

RESULTS

The facility mean direct cost for ACL reconstruction using allografts was $4,587, with a mean OR time of 92 minutes. The mean direct cost and OR time for ACL reconstruction using autografts were $3,849 and 125 minutes, respectively. Allograft ACL reconstructions were $738 more costly, and reimbursement was also higher. Allograft ACL reconstruction produced a 41.5% margin with a gross contribution margin of $3,248, whereas autografts had a reimbursement rate with a 45% margin with a gross contribution margin of $3,156.

CONCLUSIONS

In this study the cost of allograft tissue used in ACL reconstruction was not offset by the savings realized from shorter OR and recovery room times. However, in a hospital-based outpatient setting, reimbursement covered the cost of the allograft, offsetting the additional expense.

LEVEL OF EVIDENCE

Level III, retrospective comparative study for economic analysis.

Supplemental bio-tenodesis improves tibialis anterior allograft yield load in extremely low density tibiae

INTRODUCTION

Improved soft tissue tendon graft mechanical properties have led to their increased use for anterior cruciate ligament (ACL) reconstruction. Because they do not have an osseous component; however, there are greater concerns regarding tibial graft slippage during early postoperative rehabilitation and activities of daily living, particularly in patients with poor bone mineral density (BMD), such as older patients, women, smokers, and patients undergoing revision ACL reconstruction surgery.

METHODS

This in vitro biomechanical study attempted to determine the effectiveness of supplemental ACL graft fixation in low BMD tibiae. Eight paired knees (16 specimens) were harvested from female cadavers (mean age = 76, range = 60-88 years). Tibiae were assigned to either a combination bioabsorbable interference screw, bio-tenodesis screw group (Group 1, n = 8, apparent BMD = 0.44 ± 0.13 g/cm(2)) or a bioabsorbable interference screw group (Group 2, n = 8, apparent BMD = 0.44 ± 0.14 g/cm(2)). Double-strand (single loop) tibialis anterior tendon allografts were fixed in matched diameter tibial tunnels. Using a custom 6° of freedom jig, potted constructs were mounted on to a servo hydraulic device with the axial loading force aligned directly with the tibial tunnel. Constructs underwent progressive cyclic tensile loading from 10 to 150 N with a 25 N load increase every 20 cycles. This was followed by yield load to failure testing (20 mm/min).

RESULTS

Groups did not display displacement differences during progressive cyclic loading. Group 1 (312.7 ± 67.5 N) displayed 25% greater yield load at failure than Group 2 (235.0 ± 47.6 N), P = 0.045. Both groups displayed fixation levels well below the previously reported minimal safe threshold estimate for early unrestricted weight bearing, accelerated rehabilitation and activities of daily living.

CONCLUSION

Supplemental bio-tenodesis fixation may improve early tibial-soft tissue tendon graft fixation in patients that have poor tibial BMD, but study results suggest that both methods may require weightbearing, rehabilitation, and activity of daily living restrictions during the early postoperative period to prevent graft slippage.

Management of anterior cruciate ligament rupture in patients aged 40 years and older

The aim of anterior cruciate ligament (ACL) reconstruction is essentially to restore functional stability of the knee and to allow patients to return to their desired work and activities. While in the young and active population, surgery is often the best therapeutic option after an ACL tear, ACL reconstruction in middle-aged people is rather more controversial due to concerns about a higher complication rate. The purpose of our article is to establish, through a systematic review of the literature, useful decision-making criteria for the management of anterior cruciate ligament rupture in patients aged 40 years and older, guiding surgeons to the most appropriate therapeutic approach. Various reports have shown excellent results of ACL reconstruction in patients over the age of 40 in terms of subjective satisfaction, return to previous activity level, and reduced complication and failure rates. Some even document excellent outcomes in subjects of 50 years and older. Although there are limited high-level studies, data reported in the literature suggest that ACL reconstruction can be successful in appropriately selected, motivated older patients with symptomatic knee instability who want to return to participating in highly demanding sport and recreational activities. Deciding factors are based on occupation, sex, activity level of the subject, amount of time spent performing such highly demanding activities, and presence of associated knee lesions. Physiological age and activity level are more important than chronological age as deciding factors when considering ACL reconstruction.

Effect of repeated freezing-thawing on the Achilles tendon of rabbits

The increased use of allograft tissue in the reconstruction of anterior cruciate ligament has brought more focus to the effect of storage and treatment on allograft. The purpose of this study was to observe the effect of histology and biomechanics on Achilles tendon in rabbits through repeated freezing-thawing before allograft tendon transplantation. Rabbit Achilles tendons were harvested and processed according to the manufacture's protocol of tissue bank, and freezing-thawing was repeated three times (group 1) and ten times (group 2). Those received only one cycle were used as controls. Then, tendons in each group were selected randomly to make for histological observations and biomechanics test. Histological observation showed that the following changes happened as the number of freezing-thawing increased: the arrangement of tendon bundles and collagen fibrils became disordered until ruptured, cells disrupted and apparent gaps appeared between tendon bundle because the formation of ice crystals. There were significant differences between the experimental and control groups in the values of maximum load, energy of maximum load and maximum stress, whereas no significant differences existed in other values such as stiffness, maximum strain, elastic modulus, and energy density. Therefore, repeated freezing-thawing had histological and biomechanical effect on Achilles tendon in rabbits before allograft tendon transplantation. This indicates that cautions should be taken in the repeated freezing-thawing preparation of allograft tendons in clinical application.

Anterior cruciate ligament allograft surgery: underreporting of graft source, graft processing, and donor age

BACKGROUND

There has been much controversy regarding the effects of sterilization techniques and graft history on the structural integrity of allograft ligaments used in reconstruction of the anterior cruciate ligament. The purpose of this review was to comprehensively examine anterior cruciate ligament allograft studies published in the last decade to evaluate the extent to which tissue source, tissue processing techniques, and donor age are reported.

METHODS

The authors reviewed 202 articles published from 1999 through November 2009, of which 68 retrospective, prospective, biomechanical, and histology studies evaluating 4689 allografts were included.

RESULTS

The majority of studies do not accurately report key elements of graft history including tissue bank, processing or sterilization technique, or donor age. Underreporting was particularly prominent in clinical studies as compared with basic science studies. Limited reporting of allograft processing, allograft source, and donor age raises serious questions regarding the generalizability of published studies of allograft tissue for anterior cruciate ligament reconstruction. Conclusion/

CLINICAL RELEVANCE

Orthopaedic surgeons who use allograft tissue must understand the tissue treatments being used (ie, preservation methods, chemical and sterilization processes) to best inform their patients regarding the risks, benefits, and long-term outcomes when such tissues are used. A complete understanding of the implanted tissue, as well as surgeon and recipient demographics, is necessary to ensure appropriate and predictable long-term outcomes.

Effect of patient age on morphology of anterior cruciate ligament grafts at second-look arthroscopy

PURPOSE

The purpose of this study was to evaluate the effect of patient age on the morphology of anterior cruciate ligament (ACL) graft after ACL reconstruction, as well as to investigate the relation between morphology and clinical outcomes.

METHODS

Anatomic double-bundle ACL reconstruction by use of autogenous semitendinosus tendon graft was performed in 193 patients. Of these, 102 patients (51 male and 51 female patients) had consented to undergo second-look arthroscopy at the time of hardware removal within 2 years of ACL reconstruction. These patients were divided into the following 3 groups according to their age: group A, 29 years or younger (55 cases); group B, 30 to 49 years (36 cases); and group C, 50 years or older (11 cases). At second-look arthroscopy, the grafts were evaluated based on synovial coverage around the grafts, tension, and damage/tear of the grafts themselves. Clinical outcomes were evaluated with a physical examination including the Lachman test and side-to-side difference by KT-2000 knee arthrometer (MEDmetric, San Diego, CA), subjective assessment including International Knee Documentation Committee subjective assessment and Lysholm score, and sports activity level including Tegner activity scale. The Mann-Whitney U test, Kruskal-Wallis test, analysis of variance, and χ² test were used for statistical analysis.

RESULTS

Good synovial coverage over the graft was found in 49 cases (89%) in group A, 30 (83%) in group B, and 5 (46%) in group C. Synovial coverage in group C was significantly poorer than that in the other 2 groups. No statistical difference was found in tension of graft among the 3 groups, whereas the incidence of a "partial tear" tended to increase with age. With respect to clinical outcome, there was no significant difference among the 3 groups except for sports activity.

CONCLUSIONS

Although clinical outcomes were comparable among the 3 groups, synovial coverage of ACL grafts in elderly patients was significantly poorer than that in younger patients.

LEVEL OF EVIDENCE

Level II, prognostic study.

Two to five year results of primary ACL reconstruction using doubled tibialis anterior allograft

The aim of the study was to report the 2-5 year results of primary ACL reconstruction with doubled tibialis anterior allograft. Seventy-three patients who underwent primary ACL reconstruction with doubled tibialis anterior allografts with minimum 2 year follow-up were included in the study. Sixty-four patients were available for follow-up. The median age was 27 years (16-55). There were 33 men and 31 women. The median follow-up was 44.5 months (24-55 months). There were two complications, 1 DVT with subsequent PE, and 1 hardware problem. Four patients had failure of their graft, and six patients required repeat arthroscopy. The median Lysholm score was 88 (range 70-95), and the median Tegner activity score was 6.5 (range 3-10). The median IDKC was 92 (range 73-100). According to the IDKC score, 60% of patients were rated as excellent, 27% as good, and 13% as fair. A total of 25 were able to attend the clinical assessment. On KT-1000, 15 (60%) patients had less than 3 mm side-side difference. Eighteen patients (72%) had no pivot shift. ACL reconstruction with allograft tibialis anterior tendon provided good functional results with a low-failure rate at 2-5 years. There was a statistically significant difference in outcome between men and women, with men performing better on the Lysholm and the IDKC scales.

Anterior cruciate ligament reconstruction improves activity-induced pain in comparison with pain at rest in middle-aged patients with significant cartilage degeneration

BACKGROUND

Recent reports revealed that outcomes of anterior cruciate ligament (ACL) reconstruction in middle- or old-age patients are comparable with those of young patients. However, in case of concomitant arthrosis in the affected knee, there has been a paucity of literature regarding the outcomes of ACL reconstruction. We studied the level of improvement in pain originating from significant cartilage degeneration in middle-aged ACL-deficient patients after ACL reconstruction. We divided the pain into pain at rest and activity-induced pain.

HYPOTHESIS

The activity-induced pain would be more improved by ACL reconstruction than the pain at rest.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We studied 36 patients who had undergone arthroscopic isolated ACL reconstruction for functional instability with significant cartilage degeneration grade III or IV without mensical injury. All patients had activity-induced pain; 20 of these patients also had pain at rest. To assess the pain level, the visual analog scale (VAS) was employed, in addition to radiologic and clinical evaluations such as the Lachman test, KT-2000 arthrometer, and pivot shift test. The mean age of the patients was 48.6 years (range, 41-61 years); mean follow-up was 46.7 months (range, 27-74 months).

RESULTS

The preoperative mean VAS of the activity-induced pain (4.1 +/- 1.0; range, 2-6) showed significant improvement at the most recent follow-up (2.0 +/- 1.0; range, 0-4; P < .0001). However, the preoperative mean VAS of the pain at rest (2.9 +/- 0.9; range, 2-5) did not improve significantly at the most recent follow-up (2.5 +/- 0.8; range, 1-4; P = .149). The Lachman test, KT-2000 arthrometer, andpivot shift test showed significant improvement compared with preoperative outcomes (P < .0001). There was no significant difference in radiologic assessment between preoperative and postoperative outcomes (P = .082).

CONCLUSION

Anterior cruciate ligament reconstruction in middle-aged patients with significant cartilage degeneration is effective in reducing activity-induced pain and instability. Even though all patients had less than severe arthritic changes on preoperative radiographs, the pain at rest did not improve after ACL reconstruction.

Failure rate of Achilles tendon allograft in primary anterior cruciate ligament reconstruction

PURPOSE

This study was performed to determine the failure rate of patients undergoing primary anterior cruciate ligament (ACL) reconstruction with an Achilles tendon allograft by a single surgeon with the same surgical technique, graft fixation, and postoperative rehabilitation. The Achilles tendon allograft was obtained from a single source.

METHODS

Of 158 patients who underwent primary ACL reconstruction with Achilles tendon allograft, 144 were followed up at a mean of 40 months. The mean age was 29.5 years at the time of surgery. Evaluation included a questionnaire at serial follow-up visits, physical examination, and return to play.

RESULTS

Of 144 patients, 8 (5.6%) sustained traumatic reruptures or had evidence of laxity failure. Patients were divided into 4 age groups: less than 18 years, 18 to 25 years, 26 to 40 years, and 41 years or greater. Failure rates of 8.7%, 8.8%, 5.7%, and 0%, respectively, were found. A chi(2) contingency test was performed comparing patients aged 25 years or younger and those aged over 25 years with a resulting P value of .5811. No statistically significant difference between the groups of failures was seen.

CONCLUSIONS

The results of our study show that the failure rate for freeze-dried Achilles tendon allograft in primary ACL reconstruction was 8 of 144 (5.6%). When these patients were followed up for a minimum of 24 months, we found failure rates of 8.7%, 8.8%, 5.7%, and 0% in those aged less than 18 years, 18 to 25 years, 26 to 40 years, and 41 years or older, respectively. No statistically significant difference between the groups of failures was seen.

LEVEL OF EVIDENCE

Level IV, case series.

Avoiding mismatch in allograft anterior cruciate ligament reconstruction: correlation between patient height and patellar tendon length

PURPOSE

The purpose of this study was to evaluate whether a correlation exists between patient height and soft-tissue patellar tendon length.

METHODS

Magnetic resonance imaging (1.5 T) was performed for knee pathology on 403 patients. The patellar tendon length was measured in the midsagittal plane by a board-certified musculoskeletal radiologist. Patient height was recorded to the nearest inch. Patients were grouped into 6 subgroups with 4-inch range intervals based on height. The entire study group was analyzed. Subgroup analysis and gender analysis were performed to determine statistical significance.

RESULTS

The mean patellar tendon length was 45 +/- 7 mm (range, 30 to 66 mm). Wide ranges were noted among each height subgroup irrespective of gender. Significant differences were noted between most height subgroups independent of gender.

CONCLUSIONS

This study showed that a correlation exists between patient height, gender, and patellar tendon length. Although variation occurs among patients of the same height, significant differences in mean patellar tendon lengths do exist between patients in different height subgroups.

CLINICAL RELEVANCE

Parameters are provided using patient gender and height to reduce the potential for graft-construct mismatch when ordering bone-patellar tendon-bone allografts for anterior cruciate ligament reconstruction.

Anterior cruciate ligament reconstruction using patellar tendon allograft: an age-dependent outcome evaluation

PURPOSE

To compare the outcomes of a consecutive series of nonrevision bone-patellar tendon-bone (BPTB) allograft anterior cruciate ligament (ACL) reconstructions in patients aged 40 years or older and patients aged younger than 40 years.

METHODS

Prospectively collected data from consecutive BPTB allograft ACL reconstructions fixed with biodegradable interference screws and performed by a single surgeon were analyzed by use of established outcome measures. Preoperative and postoperative outcome assessments included Cincinnati, Lysholm, and Tegner scores and International Knee Documentation Committee (IKDC) activity scores. Lachman test, pivot-shift test, and KT arthrometer (MEDmetric, San Diego, CA) measurements were obtained at a minimum of 24 months after surgery.

RESULTS

In total, 32 patients met the inclusion criteria (21 men and 11 women). The mean follow-up was 35 months (range, 24 to 58 months). Of the patients, 21 were aged younger than 40 years (66%) and 11 were aged 40 years or older (34%). The mean age was 35 years (range, 18 to 55 years). In patients aged younger than 40 years, the mean postoperative Cincinnati score was 82.4 (39.1 preoperatively); Tegner score, 6.2 (3.9 preoperatively); Lysholm score, 89.5 (46.8 preoperatively); and IKDC activity score, 2.7 out of 4 (1.7 preoperatively). Five patients had a positive postoperative Lachman test, but none had a positive pivot-shift test. KT examinations showed a manual maximum difference of less than 3 mm in all but 1 patient (mean, 0.7 mm). In patients aged 40 years or older, the mean postoperative Cincinnati score was 83.8 (44.4 preoperatively); Tegner score, 6.6 (3.9 preoperatively); Lysholm score, 88.8 (50.1 preoperatively); and IKDC activity score, 2.7 out of 4 (2.1 preoperatively). One patient had a positive postoperative Lachman test, but none had a positive pivot-shift test. KT examinations showed a manual maximum difference of less than 3 mm in all but 1 patient (mean, 1.3 mm).

CONCLUSIONS

The outcomes of BPTB allograft ACL reconstructions were not different both subjectively and objectively for patients aged 40 years or older and patients aged younger than 40 years. BPTB allograft ACL reconstruction provides consistent results for patients of all age groups.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Anterior cruciate ligament reconstruction in patients over 40 years using hamstring autograft

Anterior cruciate ligament (ACL) reconstruction is becoming increasingly popular in active middle-aged patients with symptomatic instability. The purpose of this study was to retrospectively evaluate the results of ACL reconstruction in patients over the age of 40. Twenty-one patients with a median age of 44 (range 40-56) who had arthroscopically assisted reconstruction using four-stranded hamstring autograft were reviewed. RCI titanium interference screw fixation was used in the tibia, and Endobutton CL fixation in the femur. The clinical results were assessed at a mean follow-up of 2 years. The median value for the Lysholm knee score was 92 (range 74-100), and the median value for the International Knee Documentation Committee score was 83 (range 53-97). For the Tegner activity scale, the median value was 6 (range 4-8) at follow-up. The median side-to-side difference using the KT-1000 arthrometer was 2 mm (range 0-3.5 mm). Hamstring ACL reconstruction in appropriately selected middle-aged patients can yield successful and satisfactory results.

The role of anterior cruciate ligament reconstruction in the older patients, 55 years or above

Anterior cruciate ligament (ACL) deficiency can result in symptomatic functional instability of the knee regardless of the patient's age. We reviewed a single surgeon database of 908 ACL reconstructions carried out in the last 20 years for symptomatic instability. 14 patients were identified who were 55 years or above at surgery (mean: 60 years, range 55-75 years). Patients were evaluated clinically and with clinical outcome scoring and KT-1000 arthrometry assessment. 12 patients (86%) were available to attend for follow-up at a mean 9 years after ACL reconstruction. The median pre-injury Tegner score was 5.5 (range 1-7) and the median pre-operative Lysholm score was 33 (range 15-67). Initially, one patient had a good result but subsequently the patient undergone total knee replacement 5 years after ACL reconstruction. For the remainder, at the most recent review, the median Lysholm score had improved to 79 (range 43-100, P < 0.05) although it had deteriorated from the maximum achieved post-op score of 85.5 (range 53-100, P < 0.05); and the Tegner score had declined to 3 (range 1-5, P < 0.05). KT-1000 testing demonstrated a mean side-to-side difference improvement in laxity from 4.6 +/- 1.3 mm (range 3-7) to 1.5 +/- 1.2 mm (range 0-4, P < 0.05) and >2 mm difference in only one knee (for which it was known that the graft had failed at 11 years after ACL reconstruction). At review, the same knee was the only one that demonstrated a pivot shift. ACL reconstruction with autograft in the above-55 patient with minimal osteoarthritis is a safe procedure that returns stability to the knee and permits a return to a reasonable level of activity.

Tendon graft fixation in ACL reconstructionIn vitro evaluation of bioabsorbable tenodesis screw

BACKGROUND

Conventional ACL reconstruction requires sufficient tibial bone quality for secure graft fixation. We evaluated the mechanical characteristics of a supplemental tenodesis screw in cadaveric specimens.

MATERIAL AND METHODS

One group of 7 specimens from 7-paired tibiae was randomly assigned to undergo tibialis anterior tendon graft-bone tunnel fixation with a bioabsorbable interference screw, using conventional ACL reconstruction techniques. The other group of 7 specimens underwent the same procedure supplemented with a bioabsorbable tenodesis screw. All specimens were subjected to pullout testing on a servo hydraulic device.

RESULTS

Specimens in the supplemental fixation group had double the load to failure (tenodesis = 467 (SD 184) N, control group = 223 (SD 66) N, p = 0.02) and were also one-third stiffer (tenodesis = 31 (SD 13) N/mm, control group = 21 (SD 6) N/mm, p = 0.03) than the specimens in the conventional fixation group.

INTERPRETATION

Supplemental bioabsorbable tenodesis screw fixation may be advantageous for primary reconstruction in patients with low tibial bone mineral density or during revision procedures. By providing secure soft tissue graft-tibia fixation during the early phase after ACL reconstruction, supplemental tenodesis fixation may enable patients to participate safely in more intense, early rehabilitation.

Is there significant variation in the material properties of four different allografts implanted for ACL reconstruction

The aims of our study were to: (1) determine if there are differences in the material properties of tendon obtained from implanted tibialis anterior, achilles, bone-patella- bone and tibialis posterior allografts; (2) determine the variability in material properties between the implanted specimens. A total of 60 specimens were collected from fresh frozen allografts implanted at ACL reconstruction. Specimens collected included 15 tibialis anterior, 15 tibialis posterior, 15 achilles and 15 bone-patella-bone tendons. Each specimen was mounted in a custom made cryogrip. The mounted specimens were loaded onto a MTS Testline servo-hydraulic testing machine in a uni-axial tensile test configuration. Specimens were subjected to a strain rate of 5% per second until the ultimate tensile stress (UTS), failure strain and high strain modulus was calculated for each specimen after being normalized for specimen dimensions. Individual material properties were tested using one way analysis of variance (ANOVA) and post hoc Tukey's B test with a P value of <0.05 considered significant. Homogeneity of variance was assessed using the Levene's test. As a result, no significant difference was found between all four grafts with regards to UTS, failure strain or high strain linear modulus. The UTS was plotted against the modulus demonstrating a linear relationship which is typical of soft tissues. Significant variability in the results were observed. In conclusion, there was no significant statistical difference between the material properties of the four tendon allografts tested. But significant variability in results was observed within groups and between groups, which may provide one explanation for the range of results in allograft ACL reconstruction reported in the literature.

Reconstruction of the anterior cruciate ligament in patients over 50 years

The records of patients aged 50 years or over who underwent primary reconstruction of the anterior cruciate ligament between 1990 and 2002 were reviewed. There were 35 knees in 34 patients that met the inclusion criteria. The mean age of the patients was 57 years (50 to 66) and the mean clinical follow-up was for 72 months (25 to 173). A total of 23 knees were reconstructed with patellar tendon allograft, and 12 with patellar tendon autograft. The mean pre-operative knee extension was 1 degrees (-5 degrees to 10 degrees) and flexion was 129 degrees (125 degrees to 150 degrees) and at follow-up these values were 0 degrees (-5 degrees to 5 degrees) and 135 degrees (120 degrees to 150 degrees), respectively. Pre-operatively there were 31 knees (89%) with a Lachman grade 2+ or 3+. Post-operatively, 33 knees (94%) were Lachman grade 0 or 1+. The mean pre- and post-operative International Knee Documentation Committee scores were 39 (23 to 72) and 90 (33 to 100) respectively. The mean pre- and post-operative Lysholm scores were 50 (18 to 68) and 92 (28 to 100) respectively and the mean University of California Los Angeles activity scores were 8.5 before injury (4 to 10), 4.3 (3 to 6) after injury and 8.3 (4 to 10) post-operatively. There were three graft failures (8.6%) requiring revision. We conclude that reconstruction of the anterior cruciate ligament in carefully-selected patients aged 50 years or over can achieve similar results to those in younger patients, with no increased risk of complications.

Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction

Although allograft use for primary anterior cruciate ligament reconstruction has continued to increase during the last 10 years, concerns remain regarding the long-term function of allografts (primarily that they may stretch with time) and clinical efficacy compared with autograft tendons. We attempted to address these issues by prospectively comparing identical quadrupled hamstring autografts with allograft constructs for primary anterior cruciate ligament reconstruction in patients with a minimum followup of 3 years. Eighty-four patients (37 with autografts and 47 with allografts) were enrolled; the mean followup was 52 +/- 11 months for the autograft group and 48 +/- 8 months for the allograft group. Outcome measurements included objective and subjective International Knee Documentation Committee scores, Lysholm scores, Tegner activity scales, and KT-1000 arthrometer measurements. The two cohorts were similar in average age, acute or chronic nature of the anterior cruciate ligament rupture, and incidence of concomitant meniscal surgeries. At final followup, we found no difference in terms of Tegner, Lysholm, KT-1000, or International Knee Documentation Committee scores. Five anterior cruciate ligament reconstructions failed: three in the autograft group and two in the allograft group. Our data suggest laxity is not increased in allograft tendons compared with autografts and clinical outcome scores 3 to 6 years after surgery are similar.

LEVEL OF EVIDENCE

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

Avoiding allograft length mismatch during anterior cruciate ligament reconstruction: patient height as an indicator of appropriate graft length

BACKGROUND

Given the increasing use of allografts in anterior cruciate ligament reconstruction, selection of appropriate-sized grafts may help individual surgeons as well as the efficiency of the overall system for graft distribution.

HYPOTHESIS

Recipient patient height can predict the desired length for the tendinous portion of a patellar bone-tendon-bone allograft in anterior cruciate ligament reconstruction.

STUDY DESIGN

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

METHODS

A series of 414 knees in 392 consecutive patients undergoing magnetic resonance imaging evaluation of knee pain were enrolled in the study. Data collected from magnetic resonance imaging included patella and patellar tendon length and intraarticular length of the anterior cruciate ligament. Patient age, height, weight, and gender were recorded. Linear regression analysis assessed the correlation between patient height and intraarticular length of the anterior cruciate ligament as well as patellar tendon length. The effect of variance in age, weight, and gender on anterior cruciate ligament intraarticular length was also measured.

RESULTS

A strong positive correlation was found between intraarticular length of the anterior cruciate ligament and patient height (Pearson r = 0.73; P < .001). Anterior cruciate ligament length (y, in millimeters) as a function of height (x, in inches) can be expressed as y = 1.17x - 41.29. As a function of height (x, in centimeters), anterior cruciate ligament length (y, in millimeters) can be expressed as y = 0.4606x - 41.29. Age, gender, and weight did not significantly influence this relationship. A weak positive association was found between patient height and patellar tendon length.

CONCLUSION

Patient height can predict the desired length of the tendinous portion of a patellar bone-tendon-bone allograft. An addition of 10 mm is made to the predicted anterior cruciate ligament length to allow for aperture tibial and femoral fixation. Patellar bone-tendon-bone allografts can be requested based on recipient patient height as follows: 5 ft, 0 in to 5 ft, 6 in: tendinous length/total length, 45 mm/95 mm; 5 ft, 7 in to 6 ft, 1 in: 50 mm/100 mm; > 6 ft, 1 in: 55 mm/105 mm.

A literature review of autograft and allograft anterior cruciate ligament reconstruction

Knee anterior cruciate ligament reconstructive surgery has significantly evolved and now includes the option of using an allograft. This has resulted in numerous studies evaluating the advantages and disadvantages of allografts. The purpose of this literature review is to evaluate this research and present important findings to allow the selection of the most appropriate graft source when considering allograft versus autograft reconstruction.

Effects of freezing on the biomechanical and structural properties of human posterior tibial tendons

This work analyzes the effects of storage by fresh-freezing at -80 degrees C on the histological, structural and biomechanical properties of the human posterior tibial tendon (PTT), used for ACL reconstruction. Twenty-two PTTs were harvested from eleven donors. For each donor one tendon was frozen at -80 degrees C and thawed in physiological solution at 37 degrees C, and the other was tested without freezing (control). Transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and biomechanical analysis were performed. We found the following mean changes in frozen-thawed tendons compared to controls: TEM showed an increase in the mean diameter of collagen fibrils and in fibril non-occupation mean ratio, while the mean number of fibrils decreased; DSC showed a decrease in mean denaturation temperature and denaturation enthalpy. Biomechanical analysis showed a decrease in ultimate load and ultimate stress, an increase in stiffness and a decrease in ultimate strain of tendons. In conclusion fresh-freezing brings about significant changes in the biomechanical and structural properties of the human PTT. A high variability exists in the biophysical properties of tendons among individuals and in the effects of storage on tendons. Therefore, when choosing an allograft tendon, particular care is needed to choose a biomechanically suitable graft.

Anterior cruciate ligament reconstruction in patients older than 40 years: allograft versus autograft patellar tendon

BACKGROUND

Anterior cruciate ligament reconstruction is the recommended treatment for patients of all ages who are involved in sports and have symptoms of knee instability.

HYPOTHESIS

In patients older than 40 years, allograft reconstruction will have better subjective and objective results than autograft reconstruction, proving allograft to be a better graft source for this patient population.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The authors identified 63 patients meeting the criteria for this study, including 38 patients in the allograft group and 25 patients in the autograft group. All patients were older than 40 years and had at least 2 years' follow-up. Objective parameters included preinjury and postoperative Tegner activity rating scale and Lysholm scores, range of motion, thigh circumference differences, side-to-side difference at maximum manual force in anterior displacement by KT-1000 arthrometer, and clinical examination for Lachman and pivot-shift tests. Using a 15-point visual analog scale, the authors performed subjective evaluations.

RESULTS

Both groups' Tegner activity rating scale scores returned to preoperative levels. Visual analog scales and range of motion data were similar for both groups. KT-1000 arthrometer data showed a mean maximum difference of 1.46 mm for the allograft group and 0.10 mm for the autograft group (P = .398). Three patients in the allograft group showed greater than 5 mm difference, compared with none in the autograft group. There was 1 clinical failure in the allograft group. In the allograft group, 57% of patients had returned to sports by 6 months versus 25% of patients in the autograft group (P = .005), increasing to 71% and 43%, respectively, at final follow-up (P = .127).

CONCLUSION

Allograft bone-patellar tendon-bone advantages include quicker return to sporting activities; disadvantages include increased laxity and higher incidence of failure. The advantage of autograft bone-patellar tendon-bone is that it appears to be a tighter graft. The authors found that allograft was not a superior graft source in this patient population, leading them to offer both options.

Insertion torque pullout strength relationship of soft tissue tendon graft tibia tunnel fixation with a bioabsorbable interference screw

PURPOSE

The purpose of this study was to evaluate the relationship between insertion torque and the biomechanical characteristics of soft tissue tendon graft tibia fixation with a bioabsorbable interference screw.

TYPE OF STUDY

Biomechanical study.

METHODS

Doubled tibialis anterior allografts (n = 20, length = 100 mm, diameter = 9 mm) prepared for anterior cruciate ligament (ACL) reconstructions were divided into 3 groups. Maximum insertion torque was measured as grafts were fixed by the same surgeon with a 10-mm diameter, 35-mm long screw in a 7-mm diameter tunnel (dilated to 9 mm) created in either 0.16 or 0.32 g/cm3 dense synthetic bone or cadaveric tibiae (0.84 +/- 0.15 g/cm2). Tensile testing to construct failure was then performed.

RESULTS

All constructs failed by tunnel pullout. Higher density synthetic bone had greater load at failure than lower density synthetic bone (486.6 +/- 83.8 v 271.6 +/- 52.6 N, P <.0001) and a slightly greater proportion of variance could be explained in synthetic bone (R2 = 0.74, P <.0001) than in cadaveric tibiae (R2 = 0.64, P =.017). Higher density synthetic bone displayed greater stiffness than lower density synthetic bone (68.1 +/- 21.6 v 37.7 +/- 11.2 N/mm, P =.012) and a higher proportion of variance could be explained in cadaveric tibiae (R2 = 0.72, P =.008) than in synthetic bone (R2 = 0.48, P =.012). Greater insertion torque levels were seen in higher density synthetic bone (2.97 +/- 0.35 v 1.24 +/- 0.06 Nm, P <.0001) than in lower density synthetic bone, and a higher proportion of variance could be explained in synthetic bone (R2 = 0.94, P <.0001) than in cadaveric tibiae (R2 = 0.74, P =.006).

CONCLUSIONS

Strong relationships were evident between insertion torque, bone mineral density (BMD) and load to failure across constructs. Differences between the synthetic bone groups and cadaveric tibiae, however, suggest the influence of mixed cortical and cancellous bone, nonuniform structural patterning, and differing BMD levels and distributions in the cadaveric tibiae.

CLINICAL RELEVANCE

Soft tissue graft tibial tunnel fixation is directly related to insertion torque and BMD. Synthetic models with mixed bone characteristics are needed to more accurately depict human tibiae during fixation testing.