Patellar Tendon Group Research Articles

A Randomized Trial Comparing Patellar, Hamstring and Double-bundle ACL Reconstruction at 5-yrs

Objectives:This prospective, double-blind RCT compares ACL reconstruction using patellar tendon, quadruple hamstring and double-bundle hamstring grafts, by measuring patient-reported disease-specific quality of life outcome in patients with isolated ACL deficiency of the knee at a 5-years post-op.Methods:Patients (n=330; 183 males, 147 females) aged 14-50 years were randomly allocated and equally distributed to one of three anatomic ACL autograft reconstruction techniques: 1) Patellar Tendon (PT; mean age 28.7 years), 2) Quadruple-stranded Hamstring Tendon (HT; mean age 28.5 years), or 3) Double-Bundle using hamstring tendons (DB; mean age 28.3 years). Computer-generated allocation with varied block randomization was performed intra-operatively. Outcomes were measured at baseline, 3 and 6 months, 1, 2 and 5 years. Two-year results were previously reported. Primary outcome: Anterior Cruciate Ligament Quality-of-Life (ACL-QOL). Secondary outcomes: International Knee Documentation Committee (IKDC) subjective score and objective grades, pivot shift, range of motion, kneeling pain, Tegner activity level, and the Cincinnati Occupational Rating Scale. The proportion of re-ruptures, partial re-ruptures and the combined total traumatic re-injuries were compared. Radiographic evaluation was performed at baseline, 2 and 5 years; this analysis is ongoing. A 5% significance level was used for all outcomes.Results:315 randomized patients (95%) d 5-yr follow-up. There were 4 withdrawals and 11 patients lost-to-follow-up. Baseline characteristics between the groups were not different. ACL-QOL scores increased significantly from baseline over time for all groups (p=0.000). There was no difference in mean ACL-QOL score at 5-years (p=0.548): PT=82.5 (SD 17.9, 95% CI 79.0-86.0); HT=83.9 (SD 18.2, 95% CI 80.3-87.4); DB=81.1 (SD 19.3, 95% CI 77.4-84.8). At 5-years, there were no differences in the proportion of patients with a Pivot Shift grade 2 or greater (p=0.106): PT=11/98 (11%); HT=16/99 (16%); DB=23/103 (22%). Mean IKDC subjective scores were not different between groups at 5-yrs (p=0.770): PT=83.9 (SD 12.9, 95% CI = 81.4-86.5); HT=85.2 (SD 13.0, 95% CI = 82.7-87.7); DB=84.3 (SD 13.4, 95% CI = 81.7-86.9). Based on IKDC objective grades, the proportions of Normal/Nearly Normal knees at 5-years were not different between groups: PT=85/98 (87%); HT=82/99 (81%); DB=75/103 (76%), p=0.093. 5-yr Tegner activity levels and Cincinnati Occupational Scores were also not different between the groups (p=0.872 and p=0.813, respectively). Kneeling pain remained more common in the PT group (PT=10/98; HT 4/98; DB 2/101; p=0.029). More traumatic graft ruptures occurred in the HT and DB groups (PT=4/103; HT=11/105; DB=11/107; p=0.145). Revision ACL reconstructions were performed on 22 of these patients. There were an additional 11 partial graft re-ruptures (PT=0; HT=5; DB=6), with less total traumatic re-injuries in the patellar tendon group (PT=4; HT=16 and DB=17, p=0.010). Four patients had additional surgery to the index knee, not including the revision surgery between the 2 and 5-yr follow-up.Conclusion:At 5 years, there was no difference in disease-specific quality-of-life outcome or IKDC grades between the PT, HT and DB techniques for ACL reconstruction. There were significantly more traumatic graft re-injuries in the HT and DB groups compared to the PT group.

Nerve injury during anterior cruciate ligament reconstruction: A comparison between patellar and hamstring tendon grafts harvest

BackgroundTendon harvesting for anterior cruciate ligament reconstruction often injures sensory branches of the saphenous nerve. The reports on the prevalence of these injuries are scarce, while the implications on patient satisfaction are not known. Our objective was to compare the prevalence of sensory nerve injuries in patellar to hamstring autograft harvesting for anterior cruciate ligament reconstructions and follow up their postoperative course. MethodsBetween 2012 and 2014, patients who had a primary anterior cruciate ligament reconstruction with bone patellar tendon bone or hamstring autografts were included (n=94). We evaluated and compared demographic details, level of activity and postoperative sensation disturbances between both groups. Data was analyzed retrospectively. ResultsThe mean postoperative follow-up time was 23months. At the last follow-up 46 (77%) patients of the patellar tendon group and 22 (58%) of the hamstring tendons group reported on reduced sensation; however, in both groups a quarter of these patients experienced full recovery within an average of seven to eight months. There were more patients in the hamstring tendons group that reported on partial recovery. In most cases midline incisions for patellar tendons harvesting injured the infrapatellar branch and medial incisions for hamstring tendons harvesting injured the sartorial branch of the saphenous nerve. ConclusionsHarvesting tendon autografts for anterior cruciate ligament reconstructions by vertical incisions had high prevalence of saphenous nerve branches injury with a minor possibility for complete recovery within the first year. The loss of sensation was perceived by patients as a minor complication. Level of evidenceLevel IV, therapeutic case series.

Complications of anterior cruciate ligament reconstructions

Introduction. The aim of study was to analyze the results and complications of anterior cruciate ligament reconstructions, treatment and prevention possibilities. Material and Methods. We performed 210 operations: 175 with patellar tendon graft and 35 with hamstring tendons. Men were 7 times more present in our survey. The average age being 27.1 years. The average follow up was 3.2 years. The participants answered a modified Knee Ostedoarthritis Outcome Scale questionnaire set. We used clinical examination tests (Range of motion, Lachman and pivot shift) and postoperative X-rays. Results. The complication?s rate was 9% (19 patients). In patellar tendon group we registered one patellar fracture and pulmonary tromboembolism and two cases of cyclops lesions. Septic arthritis was more common among professional athletes and in hamstring tendons group. Reoperations had to be performed: in 5 cases of infections (continous irrigation and drainage), two arthrofibrosis and one osteosynthesis of patella. Graft had to be removed in 2.5% of cases and revisions happened mostly because of impropriate position of bone tunnels and new trauma. One algodystrophic syndrome happened in hamstring tendons group. Complications were successfully treated in 12 cases but 5 patients had knee contractures, so average Knee Ostedoarthritis Outcome Scale score was 88.2 points in comparison to 93.8 points in patients without complications. Seventy-three percent of patients returned to nonrestricted (sport) activities. Complications can compromise the final results of anterios cruciate ligament reconstructions. We registered similar complication rates between different grafts. Some of complications had almost every eleventh patient that resulted with reoperation at every eighteenth of them. Conclusion. The most of complications can be prevented and treated successfuly althought many questions are still left opened.

Twenty-Year Outcome of a Longitudinal Prospective Evaluation of Isolated Endoscopic Anterior Cruciate Ligament Reconstruction With Patellar Tendon or Hamstring Autograft

Background: Long-term prospective studies of isolated endoscopic anterior cruciate ligament (ACL) reconstruction are limited and may include confounding factors. Purpose: This study aimed to compare the outcomes of isolated ACL reconstruction using the patellar tendon (PT) autograft and the hamstring (HT) autograft in 180 patients over 20 years. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 180 participants undergoing isolated ACL reconstruction between 1993 and 1994 were prospectively recruited. Evaluation was performed at 1, 2, 5, 7, 10, 15, and 20 years after surgery and included the International Knee Documentation Committee (IKDC) knee ligament evaluation with radiographic evaluation, KT-1000 arthrometer side-to-side difference, and subjective scores. Results: Over 20 years, there were 16 patients (18%) and 9 patients (10%) with an ACL graft rupture in the HT and PT groups, respectively (P = .13). ACL graft rupture was associated with male sex (odds ratio [OR], 3.9; P = .007), nonideal tunnel position (OR, 3.6; P = .019), and age <18 years at the time of surgery (OR, 4.6; P = .003). The odds of a contralateral ACL rupture were increased in patients with the PT graft compared with patients with the HT graft (OR, 2.2; P = .02) and those aged <18 years at the time of surgery (OR, 3.4; P = .001). The mean IKDC scores at 20-year follow-up were 86 and 89 for the PT and HT groups, respectively (P = .18). At 20 years, 53% and 57% of the PT and HT groups participated in strenuous or very strenuous activities (P = .55), kneeling pain was present in 63% and 20% of the PT and HT groups (P = .018), and radiographic osteoarthritic change was found in 61% and 41% of the PT and HT groups (P = .008), respectively. Conclusion: Compared with patients who received the HT graft, patients who received the PT graft had significantly worse outcomes with regard to radiologically detectable osteoarthritis, kneeling pain, and contralateral ACL injury. At 20-year follow-up, both HT and PT autografts continued to provide good subjective outcomes and objective stability. However, further ACL injury is common, particularly in male individuals, younger patients, and those with tunnel malposition.

A Randomized Controlled Trial With Mean 16-Year Follow-up Comparing Hamstring and Patellar Tendon Autografts in Anterior Cruciate Ligament Reconstruction

Background: There is no consensus in the current literature on which surgical options render the best long-term results after anterior cruciate ligament (ACL) reconstruction in terms of clinical outcomes and the development of radiographic osteoarthritis (OA). Purpose: To investigate the long-term clinical and radiographic results after ACL reconstruction using either a patellar tendon (PT) autograft or a hamstring tendon (HT) autograft. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: This multicenter study was based on 2 previous randomized cohorts consisting of 193 patients who underwent unilateral primary ACL reconstruction using either a PT autograft or an HT autograft. The index surgical procedure was performed between September 1995 and January 2000. Clinical assessments, including knee laxity measurements, functional outcomes, patient-reported outcomes, and bilateral standing radiographs, were performed at the final follow-up examination. Results: At the long-term follow-up, 147 (76%) patients were examined: 61 in the PT group and 86 in the HT group. The mean (±SD) follow-up time was 191.9 ±15.1 months for the HT group and 202.6 ± 10.4 months for the PT group. Knee laxity measurements revealed significantly more patients with a normal pivot-shift test finding in the HT group compared with the PT group (71% vs 51%, respectively; P = .048); however, no significant differences were found in terms of the manual Lachman test or the KT-1000 arthrometer manual maximum test. The patients in the PT group had significantly more difficulty knee walking (P = .049). There were no significant differences between the study groups in terms of patient-reported outcomes or range of motion in the reconstructed knee. In both groups, significantly more signs of radiographic OA were found in the reconstructed knee than in the contralateral healthy knee. However, there were no significant differences between the groups in terms of radiographic OA. Conclusion: Only minor and mostly insignificant differences were found between the PT and HT autograft groups in this long-term randomized controlled trial. In both groups, significantly more signs of radiographic OA were found in the reconstructed knee than in the contralateral knee.

Effect of ACL Graft Type on Side-Step Cutting in Young Athletes

Objectives:Due to the slightly higher re-tear rate for ACL reconstruction (ACLR) with hamstring (HT) versus patellar tendon (PT), differences in movement strategies were assessed during side-step cutting in young athletes with recent ACLR to determine if graft type affected post-operative motion.Methods:Dominant limbs from 21 athletes without lower extremity injury or previous surgery (age 14.9 ± 2.0 years) and 26 limbs with recent (5.1-8.0 months post-operative) unilateral ACLR were included, 18 with HT grafts (age 16.6 ± 3.7 years) and 8 with PT (age 16.7 ± 1.2 years). Lower extremity 3-dimensional data was recorded during the deceleration phase (initial contact to maximum knee flexion) of a 45° cut. Group differences were assessed using analysis of variance with Bonferroni post-hoc tests.Results:The HT group had a slower approach velocity than controls (2.9 vs. 3.5 m/s; p=0.006) with intermediate velocity in the PT group (3.2 m/s). Both the HT and PT groups had lower peak ground reaction force (GRF) compared to controls (HT: 2.0 body weights, PT: 2.2 BW, Control: 2.8 BW; p≤0.02), along with lower peak knee flexion moments (HT: 1.4 Nm/kg, PT: 1.3 Nm/kg, Control: 2.2 Nm/kg; p=0.002). The PT group had less power absorption at the knee than controls (0.3 vs. 0.7 Nm/kg; p=0.07), while the HT group had more at the hip (0.4 vs. 0.1 Nm/kg; p=0.04). The HT group also had higher peak hip flexion (HT: 65.8°, PT: 53.9°, Control: 55.1°; p≤0.06) and hip sagittal plane excursion (HT: 9.4°, PT: 3.6°, Control: 2.8°; p≤0.05) than the PT and control groups. The HT group had lower peak knee valgus moments than controls (0.05 vs. 1.2 Nm/kg; p=0.01) as well as a greater range of frontal plane pelvic (8.2° vs. 3.4°; p=0.03) and hip (7.6° vs. 3.0°; p=0.05) motion. The PT group had intermediate values for valgus moment (0.8 Nm/kg) and pelvic (4.9°) and hip (3.3°) excursion.Conclusion:While both ACLR groups showed reduced GRFs and knee flexion moments compared with controls, the HT group demonstrated greater adaptations proximally with increased hip flexion and frontal plane pelvic and hip excursion. The lower frontal and sagittal plane hip motion in the PT group may be due to anterior knee pain associated with PT grafts. Since the HT group exhibited movement adaptations, but no observable pathologic movement patterns, such as increased knee valgus moment, other factors likely account for the observed higher re-tear rate in HT vs. PT ACLR.

Fifteen Year Prospective Comparison of Patellar &amp; Hamstring Tendon Grafts for ACL Reconstruction

Objective:This prospective longitudinal study compares isolated endoscopic ACL reconstruction utilizing 4-strand hamstring tendon (HT) or patellar tendon (PT) autograft over a 15-year period with respect to clinical outcomes and the development of osteoarthritis.Method:90 consecutive patients with isolated ACL rupture were reconstructed with a PT autograft and 90 patients received HT autograft, with an identical surgical technique. Patients were assessed at 2, 5, 7, 10 and 15 years. Assessment included the IKDC Knee Ligament Evaluation including radiographic evaluation, KT1000, kneeling pain, and clinical outcomes.Results:Subjects who received the PT graft had significantly worse outcomes at 15 years for the variables of radiologically detectable osteoarthritis (p=0.001), motion loss (p=0.02), single leg hop test (p=0.002), participation in strenuous activity (p=0.03), knee related decrease in activity level (p=0.002) and kneeling pain (p=0.03). There was no significant difference between the HT and PT groups in overall IKDC grade (p=0.28). ACL graft rupture occurred in 16% of HT group and 8% of the PT group (p=0.10). Contralateral ACL rupture occurred in significantly more PT patients (24%) than HT patients (12%) (p=0.03).Conclusion:Significant differences have developed at 15 years after surgery which were not seen at earlier reviews. Compared to the HT Group, the PT group had significantly worse outcomes with respect to radiological osteoarthritis, range of motion and functional tests but no significant difference in laxity was identified. There was a high incidence of ACL injury after reconstruction, to both the reconstructed and the contralateral knee.

Radiographic Osteoarthritis, Clinical Outcomes and Re-Injury 20 Years after ACL Reconstruction

Objective:This prospective longitudinal study compares the outcome of isolated endoscopic ACL reconstruction utilizing 4-strand hamstring tendon (HT) and patellar tendon (PT) autograft over a 20-year period.Method:Observational Series. 90 consecutive patients with isolated ACL rupture were reconstructed with a PT autograft and 90 patients received HT autograft, with an identical surgical technique. Patients were assessed at 2, 5, 7, 10, 15 and 20 years. Assessment included the IKDC Knee Ligament Evaluation including radiographic evaluation, KT1000, Lysholm Knee Score, kneeling pain, and clinical outcomes.Results:Subjects who received the PT graft had significantly worse outcomes compared to those who received the HT graft at 20 years for the variables of radiologically detectable osteoarthritis (59% v 39%, p=0.01), kneeling pain (38% v 20%, p=0.02), and incidence of contralateral ACL injury (30% v 14%, p=0.04). There was no significant difference between the HT and PT groups in overall IKDC grade (p=0.23), or IKDC subjective score (p=0.18). Subgroup gender differences were identified. The female PT group had significantly lower mean IKDC subjective scores (p=0.05), and more difficulty with kneeling (p=0.04) compared to the other subgroups. ACL graft rupture occurred in 18% of HT and 10% of the PT (p=0.13), and was associated with males (Hazard Ratio(HR)=3.9, p=0.007), age <18 years (HR=4.6, p=0.003), and non ideal radiological tunnel placement (HR=3.6, p=0.02). Contralateral ACL injury was associated with age <18 years (HR=3.4, p=0.001), and the PT graft (HR=2.2, p=0.02).Conclusion:At 20 years both HT and PT autografts continue to provide good subjective outcomes and objective stability. However, ACL reconstruction using the PT graft is associated with persisting kneeling pain and radiological osteoarthritis, compared to the HT graft. Risk factors for ACL graft rupture include males, young age, and those with tunnel malposition. This information may help in the counseling of patients undergoing this procedure and stratifying their individual risk of re-injury.

Comparison of Patellar Tendon and Hamstring Tendon Anterior Cruciate Ligament Reconstruction

Background: Numerous studies have compared patellar tendon (PT) and hamstring tendon (HS) anterior cruciate ligament (ACL) reconstructions in the short to midterm, but fewer long-term results have been published. Hypothesis: There will be no difference in functional outcome between ACL reconstruction performed with PT and HS grafts, but PT grafts will have more donor site morbidity. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Sixty-five patients undergoing ACL reconstruction were randomized to receive either a PT graft or a 4-strand HS graft. Early results were reported at 4, 8, 12, 24, and 36 months. Forty-seven patients (22 of 31 PT and 25 of 34 HS) were reviewed at a mean of 15.3 years. Results: Four graft ruptures (1 PT, 3 HS) and 6 contralateral ACL injuries (4 PT, 2 HS) occurred in the group that was reviewed. There was no statistically significant difference between the groups for any of the variables measured. There was a similar incidence of anterior knee pain and kneeling pain in both groups. The previously observed increased extension deficit in the PT group at 3 years was not present at 15 years, and there was no significant between-group difference in knee laxity. A higher proportion of patients in the PT group were participating in sport on a weekly basis (73% PT, 48% HS; P = .05). There was no difference in the degree of osteoarthritis between the groups. Conclusion: This randomized controlled trial showed that HS and PT ACL reconstructions have comparable results at an average 15-year follow-up. Contrary to the study hypothesis, some of the graft differences seen at earlier review were not present at 15 years, and patients with PT grafts were more active in sport participation. Overall, both graft types provided good long-term subjective and objective outcomes.

Do outcomes of outpatient ACL reconstruction vary with graft type?

BackgroundStudies establishing the feasibility of anterior cruciate ligament (ACL) reconstruction as an outpatient procedure in France were usually conducted with hamstring tendon grafts. The objective of this study was to evaluate the outcomes of outpatient ACL reconstruction according to whether the graft was harvested from the hamstring tendons or patellar tendon. HypothesisOutpatient ACL reconstruction can be performed using any type of graft. MethodsA single-centre retrospective study was conducted in consecutive patients older than 16years who had primary ACL reconstruction using patellar tendon or hamstring tendons, with or without lateral tenodesis. Patients who underwent other procedures on bones or peripheral ligaments and those with a previous history of ACL reconstruction were excluded. The primary evaluation criterion was the occurrence of complications within 45days after surgery. Secondary evaluation criteria were the visual analogue scale (VAS) for pain during the first 3 postoperative days, patient satisfaction on day 3, and the IKDC and Lysholm clinical scores on day 45. ResultsThe analysis included 104 knees (one knee per patient). Hamstring tendons were used in 77 (74%) knees and patellar tendon in 27 (26%) knees. In the hamstring group, 2 (2.6%) patients spent the first postoperative night in the hospital and 2 others were re-admitted. No hospitalisations were recorded in the patellar-tendon group. None of the patients required revision surgery within 45days of the reconstruction procedure. None of the postoperative criteria studied showed statistically significant differences between the two groups. DiscussionACL reconstruction can be performed on an outpatient basis using any type of graft. The main determinants of successful outpatient ACL reconstruction are a standardised clinical management strategy and an appropriate anaesthesia protocol. Level of evidenceLevel IV, retrospective study.

Patellar tendon vs. hamstrings in ACL reconstruction: Ten-year follow-up prospective randomized study

Single bundle, single tunnel reconstruction of ACL seems to be an “old procedure” after the recent development and knowledge about anatomical reconstructions of ACL (single or double bundle). Despite the new trend, prospective long-term follow-up studies on the single bundle reconstruction are necessary to get more information on a technique that has occupied the last 20 years and has been executed on millions of patients. Methods From January 2002 and February 2003, hundred eight patients were recruited for a prospective randomized trial. The exclusion criteria were previous knee operations, chondral lesions, varus deformity more than 10 degrees, limb imbalance, meniscal lesion extension more than on third of the meniscus and history of knee tendinopathies. Three groups of 36 patients each were selected by the arthroscopically assisted surgical procedure: A B-PT-B reconstruction, B hamstrings (endobutton CL-reabsorbable interference screw), and C hamstrings (endobutton CL-evolgate). A dice method was used for the graft randomization. A standard rehabilitation protocol was used for all the patients, including immediate postoperative mobilisation with a knee brace just for walking (first 3 weeks), protected weight bearing for 2 weeks, and return to full activity at 6–12 months postoperatively. The patients were followed up at 6 months, 1 year and then each year until the tenth year postoperative. Six patients in group A, 8 in group B and 11 in group C were lost at the final follow-up. The methods of evaluation included clinical and instrumented laxity testing (Rolimeter), isokinetic muscle torque measurements (Cybex II), International Knee Documentation Committee II ratings, Lysholm score, Tegner activity level, Kujala patellofemoral knee scores, and radiological tunnel enlargement measure. Results The results revealed no statistically significant differences with respect to IKDC II, Lysholm score, Isokinetic test and Kujala patellofemoral knee scores. There was an enlargement of the tunnels, statistically significant in the hamstring tendon groups, and more evident in the group B. Any widening of the tunnels from 3 to 5 years was recorded into each group. The measurement of laxity using the Rolimeter showed better results for group A without any difference statistically significant. Differently, the Tegner score was statistically favourable for PT group for the first 4 years after surgery. Radiological narrowing of the joint spaces (IKDC) from 1 to 10 years postoperatively was seen in all the groups, At 10 years follow-up, radiological findings were worse for the PT group (P Conclusions PT and hamstrings ACL reconstruction seem to show similar functional and clinical results at long-term follow-up. Tunnel widening in hamstrings groups, may be a complication in case of revision. The patellar tendon group seems to be more prone to develop osteoarthritis after 5 years postoperatively.

Lower Risk of Revision With Patellar Tendon Autografts Compared With Hamstring Autografts

Background: A number of studies have found comparable results after anterior cruciate ligament (ACL) reconstruction with patellar tendon autografts and hamstring autografts; however, few studies have been large enough to reveal differences in risk of revision with regard to clinical and demographic factors. Purpose: To present the distribution of grafts for ACL reconstruction based on data in the Scandinavian ACL registries and to compare the risk of revision between patellar tendon autografts and hamstring autografts. Potential associations with other clinical and demographic factors were also explored. Study design: Cohort study; Level of evidence, 2. Methods: A total of 45,998 primary ACL reconstructions, including 6736 patellar tendon autografts and 38,666 hamstring autografts, were identified in the Scandinavian ACL registries. The overall median follow-up time was 3 years (range, 0-8 years). To compare the risk of revision between groups of patients, univariate Kaplan-Meier analysis (with log-rank test) and the Cox proportional hazard regression model were applied. The hazard rate ratio with 95% CI was reported as a measure of effect. Results: Patellar tendon and hamstring autografts were used in 14.6% and 84.1% of the patients, respectively. The remaining patients received allografts, direct sutures, or other graft types (1.3%). The primary ACL injury occurred during soccer, team handball, or alpine activities in 67.5% of the patients in the patellar tendon group and 66.2% in the hamstring group. A total of 156 patients in the patellar tendon group and 1042 patients in the hamstring group underwent revision. The overall risk of revision was significantly lower in the patellar tendon group versus the hamstring group (hazard rate ratio = 0.63; 95% CI, 0.53-0.74), and it decreased with increasing age at surgery, although not strictly linearly. The lower risk of revision in the patellar tendon group was consistently observed across subgroups of patient sex, age, and concomitant cartilage injury (P > .05, test for interaction) but seemed to be slightly more pronounced for patients injured during certain pivoting activities (soccer, team handball, and alpine activities) compared with other activities (hazard rate ratio = 0.57 vs 0.81; P = .058, test for interaction). Conclusion: The majority of primary ACL reconstructions in Scandinavia are performed with hamstring autografts. Results from the present large prospective study show that patients receiving patellar tendon autografts have a statistically significantly lower risk of revision compared with patients receiving hamstring autografts.

Comparison of Hamstring Tendon and Patellar Tendon Grafts in Anterior Cruciate Ligament Reconstruction in a Nationwide Population-Based Cohort Study

Background: The choice of graft for anterior cruciate ligament reconstruction (ACLR) remains controversial, and despite numerous studies, there is still an ongoing debate on this topic. The 2 most widely used grafts are the hamstring tendon and patellar tendon. Hypothesis: In this study, we hypothesized that the revision rate after primary ACLR is greater when using hamstring tendon grafts compared with patellar tendon grafts. Study Design: Cohort study; Level of evidence, 2. Methods: From the nationwide population-based Danish Knee Ligament Reconstruction Registry, we identified all primary ACLR procedures (n = 13,647) performed in Denmark between July 2005 and December 2011. The end point was revision ACLR. As other end points, we used objective measurements and patient-reported outcome scores. Revision rates and relative risk estimates for revision ACLR were calculated using Cox multiple regression. Results: The use of hamstring tendon grafts increased from 68% in 2005 to 85% in 2011. The cumulative revision rates for hamstring tendon grafts at 1 and 5 years were 0.65% (95% confidence interval [CI], 0.51%-0.82%) and 4.45% (95% CI, 3.94%-5.01%), respectively. For patellar tendon grafts, the revision rate was 0.16% (95% CI, 0.05%-0.50%) at 1 year and 3.03% (95% CI, 2.27%-4.05%) at 5 years. The adjusted overall relative risk of revision surgery in the hamstring tendon group compared with the patellar tendon group was 1.41 (95% CI, 1.03-1.92), and the adjusted relative risk of undergoing revision surgery performed after 1 and 5 years was 3.82 (95% CI, 1.20-12.2) and 1.90 (95% CI, 0.43-8.40), respectively. Conclusion: In this population-based study, the use of hamstring tendon grafts in ACLR was associated with an increased risk of revision compared with patellar tendon grafts, in particular during the first year after surgery. These results demonstrate that both hamstring and patellar tendon grafts reveal good results after ACLR and suggest that graft selection should be based on an individual evaluation of patient demands and graft morbidity.

Fifteen Year Follow-up of a Randomised Comparison of Patellar Tendon and Hamstring Tendon Anterior Cruciate Ligament Reconstruction

This randomised control trial shows that hamstrings tendon and patellar tendon ACL reconstructions have comparable results at an average of 15 years follow-up. Prospective Randomised Controlled Trial. Numerous studies have compared patellar tendon (PT) and hamstring tendon (HS) ACL reconstructions in the short to mid term. This study provides long term follow-up data of a group of patients who had previously participated in a randomised controlled trial. Of the original cohort of 65 patients, 21/31 PT and 24/34 HS subjects were able to be reviewed in person at a mean of 15.2 years (range 14-16). They completed the IKDC Subjective Knee Score, Cincinnati Knee Rating and Sports Activity Scales, as well as reporting the incidence and severity of anterior knee pain and kneeling pain using visual analogue scales. Examination consisted of assessment of any effusion, range of motion, anterior knee laxity measured by KT-1000, Lachman test, and the pivot shift test. Weight-bearing PA in flexion and lateral X-rays assessed for osteoarthrosis using the Kellgren-Lawrence classification. The mean age of the group was 42 years (31-57). There were 36 males and 9 females. There was no statistically significant difference between the groups for any of the variables measured. There was a trend towards a higher incidence of kneeling pain in the PT patients, although the severity of reported kneeling pain was similar in both groups. The previously observed increased extension deficit in the PT group at three years had resolved and the mildly increased anterior knee laxity in the HS group had reduced. There was no difference in the degree of osteoarthrosis between the groups (HS: 17% > KG I, PT: 19% > KG I), but older patients had more advanced changes irrespective of graft type. This RCT shows that HS and PT ACL reconstructions have comparable and results at an average of 15 years follow-up. The degree of osteoarthrosis present in the knee is dependent on age of the patient as opposed to graft type.

Arthroscopic transtibial single-bundle posterior cruciate ligament reconstruction using patellar tendon graft compared with hamstring tendon graft

The purpose of this study was to compare the outcomes of arthroscopic transtibial single-bundle posterior cruciate ligament reconstruction using autologous patellar tendon and hamstring tendon grafts. From 1998 to 2007, 59 patients with symptomatic isolated posterior cruciate ligament injury were included in this retrospective study. Twenty-five knees were reconstructed using bone-patellar tendon-bone graft, and 34 knees were reconstructed using hamstring graft. In both groups, surgical techniques were similar, except material of fixation screws. Patients were evaluated pre-operatively and post-operatively at the latest follow-up with several parameters, including symptoms, physical examination, outcome satisfaction, functional scores, radiography and complications. Average follow-up period was 51.6months in patellar tendon group and 51.1months in hamstring tendon group. Significantly more kneeling pain (32 vs. 3%), squatting pain (24 vs. 3%), anterior knee pain (36 vs. 3%), posterior drawer laxity and osteoarthritic change were shown in patellar tendon group than in hamstring tendon group post-operatively. No significant differences were found in other parameters between both groups. Several shortcomings, including anterior knee pain, squatting pain, kneeling pain and osteoarthritic change, have to be concerned when using patellar tendon autograft. In conclusion, hamstring tendon autograft may be a better choice for transtibial tunnel PCL reconstruction.

Knee Objective Stability and Isokinetic Thigh Muscle Strength after Anterior Cruciate Ligament Reconstruction: A Randomized Six-Month Follow-Up Study

Purpose: The most frequently used grafts for intra-articular anterior cruciate ligament (ACL) reconstruction are the autologous patellar tendon (PT) or doubled semitendinosus and gracilis tendons (STG) autografts. There are still controversies about graft selection for primary ACL reconstruction. Methods: A prospective, randomized study was conducted on 57 patients who underwent arthroscopically assisted ACL reconstruction between January 2010 and February 2011. In 29 patients ACL reconstruction was performed with hamstring tendon autograft (STG group), and in 28 patients the ACL reconstruction was performed with patellar tendon autograft (PT group). At 6 months follow-up, all patients have performed the isokinetic extensor and flexor muscles strength and KT-1000 measurements. Results: At 6 months after surgery, we found significantly lower average isokinetic quadriceps peak torque in the PT group compared to the STG group at angular velocity of 60°/s. However, at the same time we did not find significant difference in flexor muscle power comparing both groups. The manual maximum KT-1000 arthrometer side-to-side difference was 1.7 ± 1.7 mm for the PT group and 1.9 ± 1.6 mm for the STG group (P=0.398). No significant correlation was found between the knee objective stability (KT-1000 measurements) and the isokinetic thigh muscle strength (extensors, Spearman’s rho=0.057, P=0.671; flexors, Spearman’s rho=0.094, P=0.489). Conclusions: Both hamstring and patellar tendon autografts provided good objective stability at 6 months after surgery In addition, regardless of which graft was used, a considerable percentage of patients continue to have strength deficits. In our opinion, the ACL-reconstructed leg should have 85% or greater return to the strength of the normal leg as one criterion before release to full sports activities. We were particularly intrigued to find only half of the competitive athletes achieved this goal at 6 months after surgery.

Paper 197: Long-term Results After ACL Reconstruction Using Hamstring vs. BPT Graft in an Implant Free Pressfit Technique: An 8 Year Follow-up

The goal of this prospective, randomized study is the long-term evaluation of functional and radiological results after implant free press-fit ACL reconstruction performed using the bone-patella-tendon (PT) vs. hamstrings (HT) graft. 62 ACL insufficient patients without any concomitant sports injuries took part in a prospective, randomized study. In the PT group 31 patients (18 male, 13 female) underwent ACL reconstruction using BPT graft. The HT group included 31 patients (15 male, 16 female) who underwent ACL reconstruction using a quadrupled hamstrings graft (semitendinosus and gracilis tendon). The time from injury to surgery was 1.51 years in group PT and 1.49 in group HT (NS). All patients were operated between 10′98 and 09′99 by the senior author. The average age in the group PT was 29.9 years (range 16-46 years) and 34.2 years (range 16-55) in group HT at the time of the operation. Both surgical procedures were performed without any implants in a press-fit technique. The same rehabilitation protocol was applied to both patient groups (accelerated rehabilitation, early weight bearing). At a mean follow-up time of 8.48 years (101.7 months) we examined 49 patients, 23 (14 male, 9 female) in group PT and 26 (14 male, 12 female) in group HT. All patients were examined 1 day pre-op, 3, 6, and 12 months and 8 years post-op with Tegner, Lysholm and the IKDC, KT-1000, one leg hop test, kneeling and knee walking test and isokinetic testing. We also performed bilateral MRI to determine the cartilage defects of both injured and uninjured knee according to the ICRS protocol and compared this with the pre-operative status. For statistical analysis we used the Student's t-test. The level of significance was p<0.05. At a mean of 8.48 years after surgery we found 6 ruptured grafts (12.2%), 3 in each group. 4 of this ruptures, 2 in the PT (8.6%) and 2 in the HT group (7.7%), were connected with new sport injuries. These patients were excluded for final examination. The Tegner Score of the other 43 patients was 4.86 in group PT vs. 5.29 in group HT (NS) compared to the pre-operative results of 4.0 vs. 4.1 (NS). The Lysholm Score was 87.2 vs. 92.47 (NS/p=0.32) compared to pre-op values of 65.4 vs. 65.7 (NS). 16 patients in the patellar tendon group and 23 patients in the hamstring group had normal or nearly normal scores in the IKDC Score (A or B) throughout the review (69.23%/88.89%). The KT-1000 stability test showed a side-to-side difference of <3mm in 92.86% of the PT group and in 88.24% of the HT group (NS). A pivot shift glide had 28.6% of the cases in group PT and 17.6% in group HT. There was no gross pivot shift in either group. Concerning ROM, there were no significant side-to-side difference in flexion deficit (2.5°/1.6°) and extension deficit (0.7°/0.5°). Isokinetic testing showed nearly normal quadriceps function in both groups (91.2%/92.4%). However, there was a significant lower hamstrings strength in the HT group (99.0%/91.4%; p=0.029), unchanged since the 12 months follow-up. The significant difference of kneeling and knee walking test between both groups at the 12 months FU persisted at the 8 year follow-up. Kneeling: 1.36/1.06 (p=0.038); knee walking: 1.64/1.06 (p=0.028). The single leg hop test was significantly better in group HT (97.0%) than in group PT (92.4%; p<0.05). MRI measurements of tunnel size did not show any tunnel widening of the femoral tunnel 8 years post-op (2.11%/0.4%). However, the tibial tunnels were significantly widened in both groups (+25.38% in group PT and +20.5% in group HT). Concerning the cartilage status, 61.6% in the PT group and 88.3% in the HT group had normal or nearly normal MRI results (p<0.05). The Caton Index for patellar height in the PT group was +0.002 compared with the uninjured knee and −0.011 in the HT group (NS). The implant free press-fit technique of ACL reconstruction using PT and HT graft is an excellent procedure to restore stability and function of the knee. Using hamstring as graft, a significant lower morbidity was noted except for a persistent hamstring deficit.

The knee adduction moment in hamstring and patellar tendon anterior cruciate ligament reconstructed knees

The external knee adduction moment during gait has previously been associated with knee osteoarthritis, and although it has been shown to be greater following anterior cruciate ligament (ACL) reconstruction surgery compared to a control group, it has not been compared between different graft types. Given that the incidence of radiographic knee osteoarthritis appears to be greater following patellar tendon compared to hamstring tendon ACL reconstruction, this study tested the hypothesis that the knee adduction moment would also be increased following patellar tendon ACL reconstruction. In 48 male participants (16 patellar tendon graft, 16 hamstring graft and 16 controls), the external knee adduction moment was measured during level walking in a gait laboratory at mean of 10months after surgery. There was no difference in the knee adduction moment between the hamstring and patellar tendon groups, and both patient groups had a significantly reduced knee adduction moment compared to the control group. In the hamstring group, the smaller adduction moment was associated with the patients walking with less knee varus whereas in the patellar tendon group, the smaller moment was associated with the patients walking with a decreased vertical ground reaction force. These results indicate that in male patients during the early stages of recovery from ACL reconstruction, the knee adduction moment is not greater than controls for either hamstring or patellar tendon graft types. Although the knee adduction moment was similar between the two graft types, the overall magnitude of the moment was influenced by different biomechanical factors. III.

Clinical Results and Risk Factors for Reinjury 15 Years After Anterior Cruciate Ligament Reconstruction

Background: There is a lack of prospective studies comparing the long-term outcome of endoscopic anterior cruciate ligament (ACL) reconstruction with either a patellar tendon or hamstring tendon autograft. Purpose: This prospective longitudinal study compared the results of isolated endoscopic ACL reconstruction utilizing a 4-strand hamstring tendon (HT) or patellar tendon (PT) autograft over a 15-year period with respect to reinjury, clinical outcomes, and the development of osteoarthritis. Study Design: Cohort study; Level of evidence, 2. Methods: Ninety consecutive patients with isolated ACL rupture were reconstructed with a PT autograft, and 90 patients received an HT autograft, with an identical surgical technique. Patients were assessed at 2, 5, 7, 10, and 15 years. Assessment included the International Knee Documentation Committee (IKDC) knee ligament evaluation including radiographic evaluation, KT-1000 arthrometer testing, and Lysholm knee score. Results: Patients who received the PT graft had significantly worse outcomes compared with those who received the HT graft at 15 years for the variables of radiologically detectable osteoarthritis (grade A: 46% in PT and 69% in HT; P = .04), motion loss (extension deficit <3°: 79% in PT and 94% in HT; P = .03), single-legged hop test (grade A: 65% in PT and 92% in HT; P = .001), participation in strenuous activity (very strenuous or strenuous: 62% of PT and 77% of HT; P = .04), and kneeling pain (moderate or greater pain: 42% of PT and 26% of HT; P = .04). There was no significant difference between the HT and PT groups in overall IKDC grade (grade A: 47% of PT and 57% of HT; P = .35). An ACL graft rupture occurred in 17% of the HT group and 8% of the PT group (P = .07). An ACL graft rupture was associated with nonideal tunnel position (odds ratio [OR], 5.0) and male sex (OR, 3.2). Contralateral ACL rupture occurred in significantly more PT patients (26%) than HT patients (12%) (P = .02) and was associated with age ≤18 years (OR, 4.1) and the PT graft (OR, 2.6). Conclusion: Anterior cruciate ligament reconstruction using ipsilateral autograft continues to show excellent results in terms of patient satisfaction, symptoms, function, activity level, and stability. The use of HT autograft does, however, show better outcomes than the PT autograft in all of these outcome measures. Additionally, at 15 years, the HT graft–reconstructed ACLs have shown a lower rate of radiological osteoarthritis.

The effects of the synovium on chondrocyte growth: an experimental study

The objective of this study was to evaluate the effects of synovium on the proliferation of the cartilage tissue and chondrocytes using a rabbit knee model as an invivo synovial culture medium. Twelve New Zealand rabbits were used as the animal model in this investigation. Standard size chondral and osteochondral cartilage grafts were taken from, respectively, the left and right knees of all the animals. Two groups of 6 animals were formed: in Group I (synovium group), grafts were placed into the synovial tissue and in group II (patellar tendon group) behind the patellar tendon of the corresponding knees. After 4months, samples were collected and evaluated macroscopically by measuring their dimensions (vertical=D1, horizontal=D2, and depth=D3) and volumes, and histologically by counting the chondrocyte number using camera lucida method. Macroscopically, the increase in average D1, D2, and D3 measurements and volume in the osteochondral specimens were significantly higher compared to the chondral specimens in both groups (P<0.05). However, no significant difference was observed between the two groups in terms of macroscopic values. Histologically, the mean chondrocyte counts in osteochondral and chondral specimens for Group I (synovium) were 20.2 and 18.1, and for Group II (patellar tendon) were 18.7 and 15.6, respectively. The mean number of chondrocytes was found to be significantly higher in osteochondral specimens than that of chondral specimens in either group (P<0.05). Overall average chondrocyte count was significantly higher for Group I compared to Group II (P<0.05). Transplantation of the cartilage grafts into the synovial tissue in rabbit knees significantly enhanced the chondrocyte production compared with the group where the grafts were transplanted into intra-articular patellar tendon. The results of this study indicate that native synovial tissue may have the potential to be used as an in vivo culture medium for osteochondral tissue growth.