Knee isokinetic performance following anterior cruciate ligament reconstruction: patellar tendon versus hamstrings graft

Objective: To compare knee isokinetic performance six months after reconstruction of the anterior cruciate ligament using grafts from either the patellar tendon or the hamstrings among patients who underwent the same rehabilitation protocol.

Methods: Thirty-four patients were evaluated (17 with grafts from the patellar tendon and 17 with grafts from the hamstrings). Operated and non-operated knees were compared with regards to the variables of peak torque, work and the hamstring/quadriceps relationship at velocities of 60º/s and 180º/s and power of 180º/s after six months of surgery.

Results: The patients with ACL reconstruction using the patellar tendon (BPTB) showed quadriceps deficits for all variables, but the flexor musculature was balanced. In the hamstring group, both the extensors and the flexors showed deficits for the variables analyzed, except for hamstring power at 180º/s.

Conclusion: Patients in the patellar tendon group had a greater quadriceps deficit compared with those in the hamstrings group. Patients in the hamstrings group had a greater muscular deficit in the flexor mechanism compared with the contralateral knee. An unbalanced H/Q ratio was observed regardless of graft type, but this was more evident in the BPTB group.     

Dynamic joint loading following hamstring and patellar tendon anterior cruciate ligament reconstruction

This study compared lower limb dynamic joint loading after hamstring (HS) and patellar tendon (PT) anterior cruciate ligament (ACL) reconstruction. A three-dimensional motion analysis and force plate system were used to determine sagittal plane kinematics and kinetics in 20 subjects who had undergone ACL reconstruction (10 HS, 10 PT) whilst they performed both horizontal and vertical hopping tasks. Results for both activities showed significantly smaller knee flexion angles and external flexion moments in the operated than the non-operated limbs in PT subjects but no difference between limbs in HS subjects. There was no difference in the summated moment (hip plus knee plus ankle) between limbs for either graft type. The peak vertical ground reaction force was greater in the operated than the non-operated limb in PT subjects during the horizontal hop. These data show functional knee kinematic and kinetic differences between the two graft types that point to an earlier or better functional recovery in patients undergoing ACL reconstruction with HS graft than PT graft.     

Intra-operative hamstring tendon graft contamination in anterior cruciate ligament reconstruction

We aimed to evaluate the possibility of hamstring tendon contamination, the correlation with clinical infection and its association with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values in 89 anterior cruciate ligament reconstructions. Two tissue samples were obtained for culture from each graft: immediately after harvesting the graft and before implantation. The ESR and the CRP were evaluated preoperatively and on the 4th and 20th postoperative days. Nine patients (10%) had positive cultures but no patient had signs of postoperative infection. All patients had ESR and CRP values elevated at the 4th postoperative day. ESR and CRP values returned to normal levels at the 20th postoperative day. Higher mean values of CRP levels at the 4th day were observed in patients with contaminated grafts compared to those with uncontaminated. Both values reached normal levels at the 20th postoperative day.     

Arthroscopic anterior cruciate ligament reconstruction with periosteum-enveloping hamstring tendon graft

Tendon–bone incorporation of a tendon graft within the bone tunnel is of priority concern when using for anterior cruciate ligament (ACL) reconstruction. Superior healing process and stronger healing strength can be achieved when periosteum is sutured on the tendon inserted into a bone tunnel. We applied this idea to ACL reconstruction for enhancing tendon graft–bone tunnel healing. This is a prospective clinical outcome study with this surgical technique at minimal 2 years follow-up. Periosteum-enveloping hamstring tendon graft has been used in 68 patients. Data from 62 patients who had been followed up completely were analyzed. All patients suffered from a grade 3 or higher grade of Lachman and anterior drawer test with a positive pivot-shift test. Clinical assessments included the Lysholm knee scores, International Knee Documentation Committee (IKDC) scores, KT-1000 instrumented testing, thigh muscle assessment, and radiographic evaluation. The median Lysholm knee score was 59 (40–70) and 94 (60–100) points (P<0.01) before and after surgery. After reconstruction, 81% of patients were able to return to moderate or strenuous activity. Four (6%) patients were found to exhibit grade 2 or more ligament laxity. Complete range of motion could be achieved in 86% of patients. Three patients (5%) had positive pivot shift. Finally, 92% of patients were assessed as normal or nearly normal rating by IKDC guideline. Bone tunnels enlargement of more than 1 mm was identified in 5% of femoral tunnels and 6% of tibial tunnels. The study shows that a satisfactory result can be achieved with the periosteum-enveloping hamstring tendon graft in ACL reconstruction. Periosteum can be easily harvested at the proximal tibia from a routine incision for hamstring tendon harvesting. Besides the potential for improving tendon–bone healing, enveloped periosteum may help to seal the intra-articular tunnel opening in the early postoperative period, and thus avoid synovial fluid reflux into the tunnel. Bone tunnel enlargement could be reduced.     

A randomized comparison of patellar tendon and hamstring tendon anterior cruciate ligament reconstruction

BACKGROUND: Patellar and hamstring tendon autografts are the most frequently used graft types for anterior cruciate ligament reconstruction, but few direct comparisons of outcomes have been published. HYPOTHESIS: There is no difference in outcome between the two types of reconstruction. STUDY DESIGN: Prospective randomized clinical trial. METHODS: After isolated anterior cruciate ligament rupture, 65 patients were randomized to receive either a patellar tendon or a four-strand hamstring tendon graft reconstruction, and results were reviewed at 4, 8, 12, 24, and 36 months. RESULTS: Pain on kneeling was more common and extension deficits were greater in the patellar tendon group. There were greater quadriceps peak torque deficits in the patellar tendon group at 4 and 8 months but not thereafter. In the hamstring tendon group, active flexion deficits were greater from 8 to 24 months, and KT-1000 arthrometer side-to-side differences in anterior knee laxity at 134 N were greater. Cincinnati knee scores, International Knee Documentation Committee ratings, and rates of return to preinjury activity levels were not significantly different between the two groups. CONCLUSIONS: Both grafts resulted in satisfactory functional outcomes but with increased morbidity in the patellar tendon group and increased knee laxity and radiographic femoral tunnel widening in the hamstring tendon group.     

Knee strength deficits after hamstring tendon and patellar tendon anterior cruciate ligament reconstruction

PURPOSE: The purpose of this study was to examine the strength of the knee flexors and knee extensors after two surgical techniques of ACL reconstruction and compare them to an age and activity level matched control group. METHODS: Twenty-four subjects who had undergone ACL reconstruction greater than 1 yr previously were placed into one of two groups according to autograft donor site: patellar tendon (BPB; N = 8) and hamstring (H; N = 16), and compared with an active, control group (N = 30). Knee flexor and extensor strength was evaluated using isovelocity dynamometry (5 speeds, eccentric and concentric, 5-95 degrees ROM). Strength maps were used to graphically analyze strength over a broad operational domain of the neuromuscular system. Average strength maps were determined for each autograft group and compared with controls. A difference map (control minus graft group) and confidence (t-test) maps were used to quantitatively identify strength deficits. RESULTS: The combined ACL group (N = 24) revealed a global 25.5% extensor strength deficit, with eccentric regional (angle and velocity matched) deficits up to 50% of control. Strength deficits covered over 86% of the sampled strength map area (P < 0.01). These knee extensor strength deficits are greater than previously reported. In addition, the BPB group demonstrated a concentric, low velocity, knee extensor strength deficit at 60-95 degrees that was not observed in the H group. Significant graft site dependent, regional knee flexor deficits of up to 50% of control were observed for the H group. CONCLUSIONS: Strength deficits localized to specific contraction types and ranges of motion were demonstrated between the ACL and control groups that were dependent upon autograft donor site. Postoperative rehabilitation protocols specific to these deficits should be devised.     

A prospective randomized study of patellar versus hamstring tendon autografts for anterior cruciate ligament reconstruction

BACKGROUND: Bone-patellar tendon-bone graft has been the most commonly used graft material in anterior cruciate reconstructions, but there has been increasing use of hamstring tendon grafts. However, no existing clinical studies show adequate support for the choice of one graft over the other. HYPOTHESIS: Hamstring tendons are equally as good as patellar tendon in anterior cruciate ligament reconstructions. STUDY DESIGN: Prospective randomized clinical trial. METHODS: Ninety-nine patients with laxity caused by a torn anterior cruciate ligament underwent arthroscopically assisted reconstruction with graft randomization according to their birth year. Grafts were either bone-patellar tendon-bone with metal interference screw fixation or double-looped hamstring tendons with metal plate fixation. There were no significant differences between the two groups preoperatively or at operation. Standard rehabilitation included immediate postoperative mobilization without a knee brace, protected weightbearing for 2 weeks, and return to full activity at 6 to 12 months. RESULTS: Forty-three patients in the patellar tendon group and 46 patients in the hamstring tendon group were available for clinical evaluation at a minimum of 21 months after surgery. No statistically significant differences were seen with respect to clinical and instrumented laxity testing, International Knee Documentation Committee Score ratings, isokinetic muscle torque measurements, and Kujala patellofemoral, Lysholm, and Tegner scores. CONCLUSION: Equal results were seen for patellar and hamstring tendon autograft anterior cruciate ligament reconstructions at 2 years after surgery. Both techniques seem to improve patients' performance.     

Tunnel expansion following anterior cruciate ligament reconstruction: a comparison of hamstring and patellar tendon autografts

Thirty patients having had anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) autograft and thirty patients having had ACL reconstruction with hamstring (HS) autograft were enrolled. All procedures were performed using an endoscopic technique with identical postoperative rehabilitation, such that the only variable was the type of graft and its fixation. Lateral and 45° posteroanterior (PA) weightbearing radiographs were performed in each patient at 6–12 (mean 9) months postoperatively in the HS group and 9–22 (mean 13) months postoperatively in the PT group. The sclerotic margins of the tunnel were measured at the widest dimension of the tunnel by a single observer and were compared with the initially drilled tunnel size after correction for radiographic magnification. For the BPTB group, all bone plugs appeared to be incorporated radiographically. On the femoral side, the bone plug was incorporated at the roof of the intercondylar notch, such that no tunnel measurement could be made. Well-defined sclerotic margins were always present at the tibial and femoral tunnels for the HS group and at the tibial tunnel for the BPTB group. The mean percentage increase in tunnel size in the PA view was 9.7% ± 14.7% for the BPTB tibial tunnel, 20.9% ± 13.4% for the HS tibial tunnel, and 30.2% ± 17.2% for the HS femoral tunnel. The mean percentage increase in tunnel size in the lateral view was 14.4% ± 16.1% for the BPTB tibial tunnel, 25.5% ± 16.7% for the HS tibial tunnel, and 28.1% ± 14.7% for the HS femoral tunnel. The difference in HS and BPTB tibial tunnel expansion on both the PA and lateral views was statistically significant (P = 0.003 and P = 0.01, respectively). Inter-observer variability was excellent with an intra-class correlation coefficient of 0.92. Tunnel expansion was significantly greater following ACL reconstruction using HS autografts than in those using BPTB autografts. The points of fixation for the HS grafts are at a greater distance from the normal insertion site and biomechanical point of action of the ACL than the points of fixation for BPTB grafts. We believe that this greater distance creates a potentially larger force moment during graft cycling which may lead to greater expansion of bone tunnels. Received: 17 March 1997 Accepted: 30 June 1997     

Arthroscopic anterior cruciate ligament reconstruction: a metaanalysis comparing patellar tendon and hamstring tendon autografts

BACKGROUND: The best choice of graft tissue for use in anterior cruciate ligament reconstruction has been the subject of debate. HYPOTHESIS: Anterior cruciate ligament reconstruction with patellar tendon autograft leads to greater knee stability than reconstruction with hamstring tendon autograft. STUDY DESIGN: Metaanalysis. METHODS: A Medline search identified articles published from January 1966 to May 2000 describing arthroscopic anterior cruciate ligament reconstruction with either patellar tendon or hamstring tendon autograft and with a minimum patient follow-up of 24 months. RESULTS: There were 1348 patients in the patellar tendon group (21 studies) and 628 patients in the hamstring tendon group (13 studies). The rate of graft failure in the patellar tendon group was significantly lower (1.9% versus 4.9%) and a significantly higher proportion of patients in the patellar tendon group had a side-to-side difference of less than 3 mm on KT-1000 arthrometer testing than in the hamstring tendon group (79% versus 73.8%). There was a higher rate of manipulation under anesthesia or lysis of adhesions (6.3% versus 3.3%) and of anterior knee pain in the patellar tendon group (17.4% versus 11.5%) and a higher incidence of hardware removal in the hamstring tendon group (5.5% versus 3.1%). CONCLUSIONS: Patellar tendon autografts had a significantly lower rate of graft failure and resulted in better static knee stability and increased patient satisfaction compared with hamstring tendon autografts. However, patellar tendon autograft reconstructions resulted in an increased rate of anterior knee pain.     

Isokinetic evaluation of anterior cruciate ligament reconstruction: quadriceps tendon versus patellar tendon

AIM: The goal of this prospective randomized study was to compare the isokinetic recovery of thigh strength after anterior cruciate ligament (ACL) reconstruction by using patellar or quadriceps tendon as graft at the 6th month follow-up. METHODS: The authors evaluated 48 patients who underwent arthroscopic ACL reconstruction using patellar tendon (PT group) or quadriceps tendon (QT group) as autograft after a 6 months follow-up undergoing the following tests: the Ergojump Bosco System springboard and Universal's FITNET computerized isokinetic system. RESULTS: The counter movement jump (CMJ) test showed a 24% (p<0.01) strength deficit in patients operated with patellar tendon and 11% in the quadriceps tendon group. Also in the leg press test the greater differences in strength (p<0.05) were verified in the patellar tendon group, above all the peak torque (PT) test carried out at 3 repetitions (15%). CONCLUSIONS: The strength deficit found in the subjects operated with quadriceps tendon were statistically lower in comparison to that verified in the patellar tendon group. A good recovery in thigh strength after 6 months in patients operated with quadriceps tendon could encourage the use of this kind of graft in order to achieve an easier rehabilitation and a faster release of the patient to daily and sports activity.     

A five-year comparison of patellar tendon versus four-strand hamstring tendon autograft for arthroscopic reconstruction of the anterior cruciate ligament

BACKGROUND: The choice of graft material for anterior cruciate ligament reconstruction is believed to play a major role in outcome, but most comparisons of graft choice have not been well controlled. HYPOTHESIS: The choice of graft material (patellar tendon or hamstring tendon) does affect clinical outcome after anterior cruciate ligament reconstruction. STUDY DESIGN: Prospective, nonrandomized clinical trial. METHODS: Two groups of 90 patients each were followed for a minimum of 5 years. RESULTS: International Knee Documentation Committee assessment revealed that more than 85% of each group had an overall score of A or B at all follow-up intervals. The median Lysholm knee score was greater than 90 for both groups at 2 and 5 years. Instrumented testing revealed no significant difference between the two groups beyond 3 years. Thirty-one percent of the patellar tendon group (25) had a fixed flexion deformity and 19% of the hamstring tendon group (14) had fixed flexion deformity at 5 years. Radiologic assessment revealed early osteoarthritic changes in 4% of the hamstring tendon group (2) and in 18% of the patellar tendon group (11) at 5 years. CONCLUSIONS: Arthroscopic reconstruction with either graft results in a similar surgical outcome, reliably restoring knee stability over a 5-year period; however, patients with patellar tendon grafts are at greater risk of developing early signs of osteoarthritis.     

Compaction versus extraction drilling for fixation of the hamstring tendon graft in anterior cruciate ligament reconstruction

Initial strength of quadrupled hamstring tendon grafts fixed with titanium interference screws was assessed in 30 pairs of porcine tibiae. Bone tunnels were drilled with either compaction drilling (stepped routers) or conventional extraction drilling (cannulated drill bits). Fifteen pairs of specimens were subjected to a single-cycle load-to-failure test, while the rest underwent a cyclic-loading test to further assess the quality of the fixation. No significant difference between the two drilling techniques was found with regard to yield load, displacement at yield load, stiffness, or mode of failure. Porcine trabecular bone mineral density was determined using peripheral quantitative computed tomography and compared with that of young women and men at a site corresponding to that of the tibial bone drill hole of an anterior cruciate ligament reconstruction. There was a significant difference between the two species (210 +/- 45 mg/cm(3) in porcine tibial bone versus 129 +/- 30 mg/cm(3) in women and 134 +/- 34 mg/cm(3) in men), suggesting that porcine knee specimens may have limitations in studies of graft fixation in anterior cruciate ligament reconstruction. We found no difference between extraction and compaction drilling in initial fixation strength of a hamstring tendon graft for anterior cruciate ligament reconstruction using a porcine model.     

Interference screw fixation of hamstring vs patellar tendon grafts for anterior cruciate ligament reconstruction

The present study was designed to investigate the fixation strength of a quadruple semitendinosus-gracilis graft compared with a middle-third bone-patellar tendon-bone graft using a new interference screw developed to fix hamstrings grafts for ACL reconstructions (RCI, Smith & Nephew Donjoy). Five pairs of human cadaveric knees from donors with a mean age of 43 (range 33–52) years were used. One knee of each pair was randomly allocated to be reconstructed on the femoral side with a semitendinosus-gracilis graft from the same donor using RCI screw fixation. As the control, the contralateral knee was correspondingly reconstructed with a bone-patellar tendon-bone graft using the same interference screw. The grafts were pulled out at a velocity of 30 mm/s by an axially applied load using a MTS machine. The mean (SD) failure load for the bone-patellar tendon-bone graft fixations was 505 (25) N, 110% stronger than the mean failure load for the semitendinosus-gracilis graft fixations, which was 240 (47) N (P = 0.003). The stiffness for the patellar tendon-bone graft fixations was 46 (11) N/mm, 120% stiffer than the semitendinosus-gracilis graft fixations, which was 22 (11) N/mm (P = 0.01). This study shows that the interference screw principle used for ACL reconstructions with hamstrings tendons is inferior to that for bone-patellar tendon-bone reconstructions although the screw was developed especially for soft-tissue fixation in bone tunnels. Received: 14 August 1996 Accepted: 25 September 1997     

Factors affecting return to sports after anterior cruciate ligament reconstruction with patellar tendon and hamstring graft: a prospective clinical investigation

In athletes, anterior cruciate ligament (ACL) reconstruction is recommended after injury to restore the normal knee function and allow subsequent return to sport. Successful ACL reconstruction with patellar tendon (PT) and hamstring tendon (HT) grafts combined with a well-structured rehabilitation program could bring athletes back to their previous level of sport activities. We prospectively followed-up 100 athletes who underwent ACL reconstruction with either PT (n=50) or HT grafts (n=50). Evaluation was done pre-operatively and post-operatively (3, 6, 12, and 24 months) using International Knee Documentation Committee (IKDC), Lysholm, Noyes, and Tegner scales. Subjective assessment numeric evaluation (SANE), knee activity rating scale (Marx) and a psychological profile questionnaire (psychovitality) were also utilized. Objective evaluations included isokinetic tests and computerized knee motion analysis. Data gathered were statistically analyzed using the Mann–Whitney non-parametric U-test. Among the 100 patients who have undergone ACL reconstruction, 65% returned to the same level of sports, 24% changed sports and 11% ceased sport activities. No significant difference (P>0.05) in outcome between PT and HT grafts were observed. No significant differences (P>0.05) were noted between athletes who “returned” to their previous sport and those who “did not return” to sports at the same level when using the IKDC, Lysholm, Noyes, and Tegner knee evaluation scales. However, significant difference was observed with the knee scores obtained by those who returned and those who completely ceased participation in sport activities. Computerized laxity test revealed that 90% of these patients have less than 3 mm side-to-side difference with no significant difference between HT and PT groups. Patients who “returned to sports” obtained significantly better scores with the Marx scale (P=0.001) and the psychovitality questionnaire (P=0.001) than those who did not. Conventional knee scales including IKDC, Lysholm, Noyes, and Tegner remain as reliable means of evaluating outcome of ACL reconstruction. However, the data obtained from these are not sufficient to determine which among the patients who had knee reconstruction can successfully return to sport. The use of the Marx knee activity rating scale and the evaluation of the athletes’ psychological profile are additional scales that can be useful in determining which among the patients treated have a better chance of returning to their pre-injury activity levels.     

Tunnel enlargement and changes in synovial fluid cytokine profile following anterior cruciate ligament reconstruction with patellar tendon and hamstring tendon autografts

There is growing evidence that cytokines such as tumor necrosis factor (TNF) , interleukin (IL) 1, IL-6, bone morphogenetic proteins (BMP), and nitric oxide (NO) play an important role in the pathogenesis of bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction. Furthermore, the release of these mediators has been considered a possible reason for the higher incidence of bone tunnel enlargement following hamstring tendon (HST) than following patellar tendon (PT) ACL reconstruction observed in several studies. In this investigation synovial fluid samples from 13 patients were collected immediately before (24±7 days after ACL rupture) and 7 days after ACL surgery and values of TNF-, IL-1, IL-6, NO, and BMP-2 were analyzed. Furthermore, the incidence of bone tunnel enlargement was assessed using radiographs 38±7 weeks after surgery. Six patients underwent autologous HST ACL reconstruction, and in seven patients an PT autograft was used. In the overall patient population there were significantly higher synovial fluid concentrations of IL-6 and BMP-2 postoperatively than preoperatively; TNF- showed a trend towards lower postoperative levels while IL-1 and NO remained unchanged. The concentrations of NO, TNF-, and IL-6 found in the present study were clearly higher than normal values given in the literature. Assessment of bone tunnel enlargement revealed an average increase in tibial tunnel width of 28.4±3.1% with comparable values for HST and PT ACL reconstructions. There was no significant correlation between bone tunnel enlargement and postoperative synovial fluid concentrations of TNF-, IL-1, IL-6, NO, and BMP-2. However, all patients with bone tunnel enlargement had higher postoperative concentrations of TNF-, IL-6, and NO in the synovial fluid. There were no significant differences in concentrations between HST and PT groups. In conclusion, we observed an association between tibial bone tunnel enlargement and elevated synovial fluid concentrations of IL-6, TNF-, and NO 7 days after ACL surgery indicating the potential involvement of these biological mediators in the pathogenesis of bone tunnel enlargement. However, there was no difference between HST and PT ACL reconstructions regarding synovial fluid contents of IL-6, TNF-, IL-1, NO, and BMP-2, suggesting a comparable biological response between these autografts following their use in ACL reconstruction.     

MRI of anterior cruciate ligament repair with patellar and hamstring tendon autografts

Objective. Several MRI sequences were used to evaluate the 2-year postoperative appearance of asymptomatic knee with a torn anterior cruciate ligament (ACL) reconstructed with bone–patellar tendon–bone (BTB) and semitendinosus and gracilis (STG) tendon autografts. Design and patients. Two groups with successful repair of ACL tear with BTB (n=10) or STG (n=10) autografts were imaged at 1.5 T with sagittal and oblique coronal proton density-, T2-weighted and sagittal STIR sequences and plain and contrast-enhanced oblique coronal T1-weighted sequences. The appearance of the graft and periligamentous tissues was evaluated. Results. In all 20 cases, the ACL graft showed homogeneous, low signal intensity with periligamentous streaks of intermediate signal intensity on T2-weighted images. In 10 cases, localised areas of intermediate signal intensity were seen in the intra-articular segment of the graft on proton density- and T1-weighted images. The graft itself did not show enhancement in either of the two groups, but mild to moderate periligamentous enhancement was detected in 10 cases. Conclusion. The MRI appearance of ACL autograft is variable on proton density- and T1-weighted images. Periligamentous tissue showing contrast enhancement is a typical MRI finding after clinically successful ACL reconstruction. Received: 22 February 2000 Revision requested: 27 June 2000 Revision received: 21 August 2000 Accepted: 23 August 2000     

Extensor mechanism function after patellar tendon graft harvest for anterior cruciate ligament reconstruction.

We evaluated extensor mechanism function in 10 patients after they had arthroscopically assisted ACL reconstruction using the central third of the patellar tendon. The patients were randomly selected 12 to 24 months after reconstruction. All had rehabilitation where range of motion was initiated within the 1st postoperative week. All patients stated that they were satisfied and considered their knee to be stable. The KT-1000 maximum measurements (30 to 40 pounds) averaged an increase of 1.7 mm when compared with the opposite knee. Subjective complaints, such as anterior knee pain, grating, and weakness, were common and only 3 of 10 patients returned to all of their preinjury sports. Persistent radiographic abnormalities were common. Physical examination and functional testing also revealed persistent dysfunction of the extensor mechanism in patients with radiographic abnormalities. Isokinetic testing at 60 deg/sec showed an average quadriceps deficit of 18% compared to the normal extremity. Axial computed tomography scans revealed significant decrease in quadriceps cross-sectional area. Magnetic resonance imaging and computed tomography confirmed persistent defects at the harvest site; there was significant anterior knee scar formation in these patients. Despite achieving ligamentous stability, patients still experienced permanent weakness, functional deficits, patellar chondrosis, and pain after ACL reconstruction using the central one-third of the patellar tendon.     

Primary anterior cruciate ligament reconstruction using contralateral patellar tendon autograft

Primary ACL reconstruction using a contralateral patellar tendon autograft is an effective means of achieving symmetrical range of motion and strength after surgery. When the graft is harvested from the ipsilateral knee, the rehabilitation for the ACL graft and for the graft-donor site are different and have opposing goals. Rehabilitation for the ACL graft involves obtaining full range of motion, reducing swelling, and providing the appropriate stress to achieve graft maturation. Rehabilitation for the graft-donor site involves performing high-repetition strengthening exercises to regain size and strength, best achieved when begun immediately after surgery.