Pigmented villonodular synovitis after anterior cruciate ligament reconstruction using active bioprosthetic composite artificial ligament.

Pigmented villonodular synovitis (PVNS) is a proliferative disease that develops in the synovium of joints, especially the knee joints. A 52-year-old man visited our hospital with left knee pain, swelling and symptoms of collapse. Twenty-one years earlier, he had undergone anterior cruciate ligament (ACL) reconstruction using an active bioprosthetic composite (ABC) as an artificial ligament. T1 and T2 weighted magnetic resonance imaging of the knee joint showed rupture of the ABC ligament and low signal intensity of hyperplastic synovium. Arthroscopic total synovectomy without ACL reconstruction was performed and the lesion was histopathologically diagnosed as diffuse PVNS. Clinical outcomes included good pain relief and no recurrence of the disease after 5 years of follow-up.

Does posterior tibial slope affect the results of conservative treatment for anterior cruciate ligament tears?

OBJECTIVE: To evaluate the association between posterior tibial slope (PTS) and the short-term results of conservative treatment for the patients with anterior cruciate ligament (ACL) tears. METHODS: Thirty-seven patients (37 knees: male 33, female 4) who were managed with the same treatment protocols for ACL tears were included. All patients applied ACL brace and underwent standardized rehabilitation protocol. Group A consisted of 14 patients with successful results after conservative management and group B consisted of 23 patients who received operative treatments due to failed conservative management. For each group, a plain radiograph was used to measure the PTS. The demographic data of patients and differences of PTS between each group were analyzed. RESULTS: The mean age was 33.2 years in group A and 29.7 years in group B, respectively (p = 0.8). There was no significant difference between each group in terms of gender, body mass index, and injury mechanism. There was no significant difference between each group in the classification according to the isolated or combined injury (p = 0.83). The mean PTS was 8.3° in group A and 10.2° in group B. The mean PTS in group A was significantly lower than that in group B (p = 0.03). CONCLUSIONS: The patients with successful results after conservative management had a lower mean PTS than those with failed conservative treatment (8.3° vs. 10.2°, p = 0.03). The failure of conservative treatment after ACL tear was found to be associated with increased PTS.

Iatrogenic Medial Collateral Ligament Injury by Valgus Stress During Arthroscopic Surgery of the Knee.

PURPOSE: To evaluate the radiographic and clinical follow-up results of iatrogenic medial collateral ligament (MCL) injuries caused by valgus stress during arthroscopic surgery of the knee. METHODS: This study retrospectively evaluated 15 knees in 15 patients (8 female and 7 male patients), with a mean age of 58 years (range, 45-66 years), with iatrogenic MCL injuries caused by valgus stress during arthroscopic surgery of the knee. All patients were treated conservatively without an immobilizer or brace. The mean follow-up period was 24 months (range, 18-51 months). Evaluations included magnetic resonance imaging immediately postoperatively, as well as physical examinations and valgus stress radiographs (at 0° and 30° of knee flexion) 6 weeks after surgery and at final follow-up. RESULTS: Postoperative magnetic resonance imaging in all patients showed increased signal intensity, swelling, and partial loss of continuity at the meniscofemoral portion of the MCL. Physical examination showed mild tenderness in only 1 patient after 6 weeks and none at final follow-up. Valgus stress tests and valgus stress radiographs showed no significant differences between the injured and uninjured knees at 6 weeks postoperatively and at final follow-up (P > .05). CONCLUSIONS: Iatrogenic MCL injuries during arthroscopic knee surgery could be treated successfully without a splint or brace. LEVEL OF EVIDENCE: Level IV, prognostic case series.

Does Posterior Tibial Slope Affect Graft Rupture Following Anterior Cruciate Ligament Reconstruction?

PURPOSE: The purpose of this study was to evaluate the association between posterior tibial slope (PTS) and anterior cruciate ligament (ACL) graft rupture in patients who have undergone ACL reconstruction by comparing results in patients who experienced graft rupture and a matched control group. METHODS: The study included 64 knees of 64 patients (58 men and 6 women), of mean age 31 years (range, 18-60 years) who underwent revision ACL reconstruction for ACL graft rupture, as well as a control group without ACL graft rupture matched for age, sex, body mass index (BMI), and left or right side. The mean time to failure in study group was 48.5 months, and after revision surgeries, the mean follow-up period was 37.7 months. The graft used for the primary surgery was autograft in 3 patients (4.7%) and allograft in 49 patients (76.6%). The type of graft could not be confirmed in the remaining 12 patients (18.7%). PTS was measured on plain radiographs and compared in the 2 groups. RESULTS: Mean PTS was significantly higher in patients with (13.2° ± 2.5°; range, 8.5°-18.2°) than without (10.9° ± 3.1°; range, 4.9°-13.6°) rerupture (P < .01). When mean PTS was compared in the 37 patients who underwent primary surgery by the same surgeon, it was significantly higher in patients with (13.5° ± 2.5°; range, 8.5°-18.2°) than without (11.1° ± 2.9°; range, 5.1°-13.6°) rerupture (P < .01). PTS in patients with rerupture was not significantly associated with age, gender, BMI, and right or left side. The odds ratio of ACL graft rupture in knees with PTS ≥12° was 4.52 (P < .001). CONCLUSIONS: This study showed that mean PTS was significantly greater in patients with than without noncontact ACL graft rerupture (13.2° vs 10.9°, P < .01). The failure of ACL reconstruction appears to be associated with increased PTS, with PTS ≥12° a risk factor for the failure of ACL reconstruction. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Preemptive Femoral Nerve Block Could Reduce the Rebound Pain After Periarticular Injection in Total Knee Arthroplasty.

BACKGROUND: We evaluated the effectiveness of postoperative pain management using intraoperative periarticular injection (PAI) and/or electromyography-guided preoperative femoral nerve block (FNB) in knees undergoing total knee arthroplasty (TKA). METHODS: This study included 90 patients (90 knees) who underwent primary TKA. Thirty patients received a single injection of electromyography-guided FNB, 30 received intraoperative PAI, and 30 received both. Pain at rest and while moving was evaluated by a visual analog scale (VAS) at 0, 4, 8, 24, and 48 hours. Postoperative range of motion, time to walking, amount of opioid consumption, and complications were analyzed. RESULTS: VAS immediately after surgery was significantly higher in the FNB group than in the PAI and combined groups, but did not differ significantly in the latter 2 groups. VAS after 4 and 8 hours showed similar results. VAS after 24 hours was significantly higher in the PAI than in the FNB and combined groups. After 48 hours, there were no differences among the 3 groups. Total opioid consumption was lower in the combined than in the FNB and PAI groups. Postoperative range of motion and time to walking were similar in the 3 groups. CONCLUSION: PAI was more effective than FNB during the early (0-8 hours) postoperative period after TKA. Patients treated with PAI, however, experienced rebound pain at 24 hours. The combination of PAI and FNB may provide greater postoperative pain management than either alone for the first 24 hours after TKA.

Symptomatic mucoid degeneration of the anterior cruciate ligament.

PURPOSE: Mucoid degeneration of the anterior cruciate ligament (ACL) is a little-known entity. The aim of this study was to detail the clinical, radiological, arthroscopic and pathological findings of this condition and to report clinical outcomes following arthroscopic partial excision of the ACL. METHODS: Between 1999 and 2009, 80 knees in 78 patients were diagnosed as having mucoid degeneration of the ACL based on MRI and clinical findings, and subsequently underwent arthroscopic treatment. Of these, 68 knees in 66 patients, with a median age of 51 years (range, 35-75 years), were followed-up for at least one year. RESULTS: All patients had insidious onset of knee pain, while 56 knees (82 %) had associated extension deficits and 36 knees (53 %) had restricted flexion. MRI findings typically showed diffuse thickening and increased signal intensity of the ACL. Arthroscopic examination revealed notch impingement and bulging of hypertrophied ACL into lateral compartments. Associated lesions included meniscal tears in 33 knees and chondral lesions of at least Outerbridge grade 2 in 56 knees. All knees underwent arthroscopic partial excision of the hypertrophied ACL, with three undergoing preoperative and 30 undergoing concomitant meniscectomies. Pain relief was achieved in 58 of 62 knees (94 %) following partial excision of the ACL. Extension deficits were normalized in 49 of 56 knees (88 %), and restricted flexion was normalized in 33 of 36 affected knees (92 %). Four knees of four patients had postoperative symptoms of anterior instability. CONCLUSIONS: Pain and limitation of motion due to mucoid degeneration of the ACL can be improved by arthroscopic partial excision of the ACL with or without notchplasty. However, one potential complication is the development of postoperative symptoms of anterior instability. LEVEL OF EVIDENCE: Retrospective study, Level IV.

Relation between mucoid degeneration of the anterior cruciate ligament and posterior tibial slope.

PURPOSE: The purpose was to analyze the association between posterior tibial slope (PTS) and mucoid degeneration of the anterior cruciate ligament (ACL). METHODS: From October 1999 to May 2010, 84 arthroscopies were performed in 82 patients (18 men and 64 women) with mucoid degeneration of the ACL. The mean patient age was 53 years (range, 25 to 75 years). In addition to this patient group (group I), the study included a control group without mucoid degeneration of the ACL that was randomly matched for age, sex, body mass index, left or right side, and associated lesions (group II). For each group, the diagnosis was made by use of magnetic resonance imaging and arthroscopy, and a plain lateral radiograph was used to measure the PTS. RESULTS: The mean PTS was 13.5° ± 2.6° (range, 8.2° to 19.5°) in group I and 9.4° ± 2.5° (range, 4.8° to 15.5°) in group II. The mean PTS in group I was significantly greater than that in group II (P < .001). For group I, the mean PTS of the involved knee was significantly greater than that of the uninvolved contralateral knee (P = .044). There were no differences according to age, sex, left or right side, body weight, and body mass index (P > .05). CONCLUSIONS: Mucoid degeneration of the ACL was found to be associated with an increased PTS. The patients with mucoid degeneration of the ACL had a greater mean PTS than matched control patients (13.5° v. 9.4°, P < .001). LEVEL OF EVIDENCE: Level III, diagnostic study of nonconsecutive patients without consistently applied gold standard.

The Prevalence of Vitamin D Deficiency in Patients Undergoing Total Knee Arthroplasty: A Propensity Score Matching Analysis.

PURPOSE: We investigated and compared the serum 25-OH vitamin D [25(OH)D] level and prevalence of vitamin D deficiency (VDD) between patients who underwent total knee arthroplasty (TKA) and healthy participants through a matched analysis. METHODS: The unmatched case group consisted of 824 patients who underwent TKA and the unmatched control group 2,794 healthy participants examined at our institution. The control group was matched on the various characteristics-sex, age, weight, body mass index (BMI), blood chemistry, and season of sampling-through propensity score matching (PSM). After PSM, 501 and 721 patients were matched in the case and control group, respectively. Levels of blood chemistry including 25(OH)D were examined and VDD was defined as < 20 ng/mL. RESULTS: The average serum 25(OH)D level was significantly lower in the OA group (15.3 ng/mL) than that in the control group (19.9 ng/mL, p < 0.001). When categorized using a 20 ng/mL cutoff, the VDD prevalence was 75.0% in the OA group and 59.4% in the control group. The prevalence of vitamin D insufficiency was 18.4% in the OA group and 24.5% in the control group. The prevalence of vitamin D sufficiency was 6.8% in the OA group and 15.9% in the control group (p < 0.001). CONCLUSIONS: The patients who underwent TKA had lower serum 25(OH)D level and higher VDD prevalence compared to the healthy participants who matched using PSM. There were no differences in VDD rates by sex or obesity and the VDD prevalence was more than 70% during all season. Therefore, in patients undergoing TKA, general attention to VDD is required regardless of sex, obesity, and season. Serum 25-OH vitamin D [25(OH)D] level and vitamin D deficiency (VDD) prevalence were compared between patients undergoing total knee arthroplasty and healthy individuals. The differences in serum 25(OH)D level and VDD prevalence were significant between the two groups after propensity score matching.

Three- to six-year follow-up results after high-flexion total knee arthroplasty: can we allow passive deep knee bending?

PURPOSE: We evaluated 3- to 6-year clinical and radiological follow-up results after NexGen® LPS-flex total knee arthroplasty (TKA). METHODS: A retrospective evaluation was undertaken of 218 knees in 166 patients (22 males, 144 females) who were followed up for more than 3 years after TKA. Evaluations included preoperative and postoperative range of motion (ROM) measurement, Knee Society (KS) Score, tibiofemoral angle and assessment of postoperative complications. RESULTS: TKA resulted in a significant ROM increase from a mean flexion contracture of 9° (range 0°-20°) and further flexion of 117° (range 80°-155°) to a mean flexion contracture of 2° (range 0°-10°) and a further flexion of 131° (range 95°-155°). KS knee and function scores significantly improved from 52 and 38 before surgery to 87 and 82 after surgery, respectively. The tibiofemoral angle significantly improved from varus 5.7° to valgus 5.4°. Progressive radiolucent lines around the femoral component on radiographs were observed in 30 knees (13.8%, 27 patients), and more of those knees, could squat than non-radiolucent knees (76.7 vs. 20.2%; P<0.05). Seven knees (3.2%, 6 patients) were revised at a mean 49 months after the index operation. CONCLUSIONS: While NexGen® LPS-flex TKA satisfactorily improved ROM, it was associated with a relatively high incidence of early loosening of the femoral components. This might be associated with passive-maximal flexion activity, such as squatting or kneeling. The clinical relevance of this study is that squatting or kneeling, common activity in Asian, may not be allowed after NexGen® LPS-flex TKA.

The effect of patellar thickness changes on patellar tilt in total knee arthroplasty.

We hypothesized that changes in patellar thickness following patellar resurfacing affect patellar tilt in total knee arthroplasty (TKA) patients. The study enrolled 272 TKAs and categorized them into four groups according to change in patellar thickness: (A) thinner by 1 mm or more, (B) equal or thinner by less than 1 mm, (C) thicker by 1 mm or less, and (D) thicker by more than 1 mm. Patellar tilt angle was measured postoperatively using Merchant radiography. There were no significant differences in postoperative patellar tilt among groups A, B, and C (n.s). However, the postoperative patellar tilting angle of group D was significantly higher than that of all other groups (P < 0.05). Postoperative patellar tilt increased when the postoperative patella was >1 mm thicker than the preoperative patella.

What have we learned from LCS mobile-bearing knee system?

Three hundred and sixty-four low contact stress (LCS) total knee arthroplasties that could be followed up for more than 5 years were clinically and radiographically analyzed. The median postoperative Hospital for Special Surgery score improved from 56 (range 32-77) to 91 (range 64-100) points, but median range of motion did not change from 120° (range 50°-135°) to 120° (range 85°-135°). Complications occurred in 16 cases (4%), and included postoperative polyethylene dislocation and intraoperative tibial condylar fracture, while five knees (1%) required revision surgery due to mechanical reasons. The overall prosthesis survival rate was 91% at 12 years. Although the LCS mobile-bearing knee system has theoretical advantages in terms of wear and loosening, the problem of polyethylene dislocation, intraoperative tibial fracture, and radiolucent lines should be solved for long survival. The clinical relevance of this study is that the LCS system provided good clinical and survival results.

Preoperative vitamin D level does not affect the short-term functional outcome after total knee arthroplasty in elderly women.

BACKGROUND: We aimed to evaluate the effect of vitamin D levels on the functional outcome of elderly women who underwent total knee arthroplasty (TKA). METHODS: Seven hundred and four patients (1013 knees) who underwent primary TKA were included in our retrospective study. Preoperative vitamin D levels were measured and the relationship analyzed between these and age, weight, height, body mass index, and bone mineral density. Two hundred and twenty patients (220 knees) who received unilateral TKA and were followed up for more than 1 year after operation were divided into two groups: Group 1, serum 25-hydroxyvitamin D3 (25(OH)D3) level < 20 ng/ml; and Group 2, 25(OH)D3 level ≥ 20 ng/ml. Both groups were evaluated for the relationship between vitamin D levels and postoperative Visual Analogue Scale (VAS) score, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), and Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. RESULTS: The number of vitamin D-deficient patients (< 20 ng/ml of serum 25(OH)D3 level) was 556 (79.0%). In the correlation analysis, the vitamin D level was negatively correlated with weight only (p = 0.033). No significant differences were observed between the groups in terms of postoperative VAS score, KSKS, KSFS, and WOMAC score. CONCLUSIONS: Vitamin D deficiency was highly prevalent in patients who underwent TKA. Vitamin D levels negatively correlated with weight. Low vitamin D level was not a risk factor for unsatisfactory TKA outcome in elderly women.

Migration of polyethylene fixation screw after total knee arthroplasty.

Duracon (Howmedica, Rutherford, NJ) posterior stabilized total knee system has a snap fit locking mechanism of a tibial polyethylene, including an additional locking screw for further fixation of polyethylene. We report 13 cases of locking screw migration from tibial component after Duracon posterior stabilized primary total knee arthroplasty. Among 13 knees, screw migration in 10 asymptomatic cases was incidentally detected during regular follow-up, and they were just observed in the outpatient clinic. Only 3 knees had moderate pain, swelling, and instability, and revision was done on 2 of 3 knees.

Enhanced Reality Showing Long-Lasting Analgesia after Total Knee Arthroplasty: Prospective, Randomized Clinical Trial.

To overcome the limitation of short-term efficacy of virtual reality (VR), an enhanced reality (ER) analgesia, (combination of the VR, real-time motion capture, mirror therapy [MT]) involving a high degree of patients' presence or embodiment was explored. Patients, who underwent unilateral total knee arthroplasty (TKA), received ER analgesia. The duration was 5 times a week, for 2 weeks for one group and 5 times a week, for 1 week in the other. Visual Analogue Scale (VAS) at rest and during movement, active knee range of motion (ROM) for flexion and extension were measured repeatedly. After screening 157 patients, 60 were included. Pre-interventional evaluation was performed at 6.7 days and ER was initiated at 12.4 days after surgery. Evaluation was performed at 5, 12, 33 days after the initiation of ER. Analgesia in the 2 week therapy group was effective until the third evaluation (p = 0.000), whereas in the other group, it was effective only until the second evaluation (p = 0.010). Improvement in ROM in the 2 week group was also maintained until the third evaluation (p = 0.037, p = 0.009). It could lay the foundations for the development of safe and long-lasting analgesic tools.

Synovial fluid levels of TWEAK and matrix metalloproteinase 1 in patients with osteoarthritis, and associations with disease severity.

PURPOSE: This study assessed the levels of soluble tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and matrix metalloproteinase 1 (MMP-1) in the synovial fluid from osteoarthritic knees to determine their role as well as the relationship between these levels and the severity of osteoarthritis (OA). METHODS: Synovial fluid was obtained from 44 knees of 40 patients. The Kellgren-Lawrence (KL) grade was measured using radiograph. The concentration of TWEAK and MMP-1 in the synovial fluid was assessed by enzyme-linked immunosorbent assay. The underlying inflammatory factors (erythrocyte sedimentation rate and C-reactive protein) were also measured. We analyzed the correlation between the factors measured. In addition, the samples were subdivided into three groups according to OA severity using the KL grade, and the differences in TWEAK and MMP-1 levels between groups were analyzed. RESULTS: The TWEAK and MMP-1 levels in the synovial fluid showed a positive correlation with each other. The TWEAK and MMP-1 levels were compared between the three groups according to the KL grade, and the levels showed a significant difference. A post hoc test demonstrated that the group with advanced OA showed a lower concentration of both factors when compared to groups with early OA. CONCLUSION: The concentration of TWEAK and MMP-1 in the synovial fluid were relatively high in the early stage of OA, and the levels decreased as the OA progressed.

Bilateral Hypoplasia of the Medial and Lateral Menisci.

Hypoplasia of the meniscus is a very rare congenital abnormality, with only a few cases reported to date. A 9-year-old girl visited our hospital due to lateral knee pain following a hyperextension injury to the left knee. Magnetic resonance imaging showed hypoplasia of the medial and lateral menisci, as well as a posterior horn tear of the lateral meniscus, in both knee joints. To our knowledge, this is the first report of a patient with hypoplasia of the medial and lateral menisci in both knee joints.

Classification of postaxial polydactyly of the foot.

BACKGROUND: The origins and shapes of accessory digits in postaxial polydactyly of the foot were analyzed morphologically and radiographically, and their characteristics were determined. A simple classification method was then devised to assist in determining the most appropriate treatment options. METHODS: We evaluated 113 feet of 95 patients who had surgery for the treatment of postaxial polydactyly between 1998 and 2002. Based on the morphologic, radiographic, and operative findings, the cases were classified according to the origin of the accessory digit: middle phalangeal, proximal phalangeal, floating, fifth metatarsal, or fourth metatarsal. The proximal phalangeal type was further divided into three subtypes: proximal phalangeal lateral type, proximal phalangeal medial, and proximal phalangeal head. RESULTS: Of the 113 feet, 36 were middle phalangeal type, 45 were proximal phalangeal type, 5 were floating type, 15 were fifth metatarsal type, and 12 were fourth metatarsal type. Of the proximal phalangeal types, 15 were laterally duplicated supernumerary sixth digits, and 17 were medially duplicated supernumerary fifth digits. The duplicated digits of the remaining 13 originated at the distal portion of the proximal phalanx. In the middle phalangeal, proximal phalangeal head, proximal phalangeal medial, and fourth metatarsal types, the medial accessory fifth digit was an abnormally duplicated digit, which was excised. In the proximal phalangeal lateral, floating, and fifth metatarsal types, the lat eral accessory sixth digit was excised. For the children in this study, we did not perform reconstruction of the deep transverse metatarsal ligament or collateral ligament. Also, we did not use longitudinal pin fixation. Skin necrosis occurred in 10 feet that resolved, and in five of the 15 feet of the 5th metatarsal medial deviation occurred. CONCLUSIONS: Based on the morphologic, radiographic, and operative findings, we suggest a classification method of postaxial polydactyly of the foot. We believe this is a straightforward and useful method for the treatment of postaxial polydactyly.

Relationship between Mucoid Degeneration of the Anterior Cruciate Ligament and Posterior Tibial Slope in Patients with Total Knee Arthroplasty.

PURPOSE: The purpose was to analyze the relationship between posterior tibial slope (PTS) and mucoid degeneration of the anterior cruciate ligament (ACL) in patients with total knee arthroplasty. MATERIALS AND METHODS: Four hundred and twenty-four patients (24 males and 400 females; 636 knees) who received total knee arthroplasty for osteoarthritis were included. Their mean age was 68.9 years (range, 48 to 88 years). The patients were classified into three groups according to the status of ACL; normal ACL group (group I), mucoid degeneration of ACL group (group II) and ruptured or absent ACL group (group III). Plain lateral radiographs were used to measure the PTS and the values were compared among groups. RESULTS: There were no significant differences with regard to gender, age and left-to-right side ratio among groups (p>0.05). The mean PTS was 9.9° (range, 0.6° to 20.1°) in group I (161 knees), 10.8° (range, 0.2° to 21.8°) in group II (342 knees) and 12.3° (range, 2° to 22.2°) in group III (133 knees), which showed significant differences (p<0.001). CONCLUSIONS: The patients with mucoid degeneration of the ACL and those with ruptured or absent ACL had greater PTS than those with normal ACL. These findings suggest that an increased PTS may be one of the causative factors for mucoid degeneration of the ACL.

Patterns and Influencing Factors of Medial Meniscus Tears in Varus Knee Osteoarthritis.

PURPOSE: To investigate the patterns of medial meniscus (MM) tears in patients with varus knee osteoarthritis who underwent total knee arthroplasty and analyze the factors that could affect MM tears. MATERIALS AND METHODS: The patients (365 knees, 268 patients) were classified into three groups; group I with MM posterior horn (PH) tear only; group II with MM root tear only; and group III with MMPH plus root tear. The following factors were evaluated: age, gender, body mass index, varus deviation of the mechanical axis, medial proximal tibial angle, posterior tibial slope (PTS), and anterior cruciate ligament (ACL) integrity (normal, degeneration, and tear or absence). RESULTS: MM tears were identified in all knees. The patterns of the combined MMPH tears in group III were less complex than those in group I. Varus deviation and PTS were significantly greater in group III than groups I and II. In group III, there were significantly more cases of ACL tear or absence than groups I and II. The others showed no differences among three groups. CONCLUSIONS: Severe varus knee osteoarthritis was always accompanied by MM tears. Risk factors for MMPH plus root tears were severe varus deformity, great PTS, and ACL tear or absence.

Modified transtibial versus anteromedial portal technique in anatomic single-bundle anterior cruciate ligament reconstruction: comparison of femoral tunnel position and clinical results.

BACKGROUND: Although several studies have compared a conventional transtibial technique with an anteromedial (AM) portal technique for single-bundle (SB) anterior cruciate ligament (ACL) reconstruction, no study to date has investigated whether the modified transtibial technique results in the femoral tunnel being in a similar anatomic position and produces similar clinical outcomes with those of the AM portal technique. PURPOSE: To compare the clinical outcomes and femoral tunnel position of SB ACL reconstruction using a modified transtibial technique (creating a femoral tunnel with varus and internal rotation of the tibia as well as modification of the tibial tunnel orientation) with those of SB ACL reconstruction using an AM portal technique. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 40 patients (40 knees) who underwent arthroscopic SB ACL reconstruction were included in this study. Patients were randomized using a computer-generated sequence into 2 groups: 20 patients by the modified transtibial technique (group 1) and 20 patients by the AM portal technique (group 2). Clinical evaluations included the 2000 International Knee Documentation Committee (IKDC) subjective knee score, Lysholm knee score, Tegner activity scale, Lachman test, pivot-shift test, 2000 IKDC knee examination, and KT-1000 arthrometer measurement. Three-dimensional computed tomography scans were analyzed according to the quadrant method, and the obliquity of the femoral tunnels in the coronal and sagittal planes and the size of the tunnel orifice were measured. RESULTS: All clinical parameters improved significantly after SB ACL reconstruction, with no between-group differences. The mean distance of the femoral tunnel center location from the posterior condylar surface (0.8% difference; P = .167) and from the Blumensaat line (2.1% difference; P = .067) was similar in groups 1 and 2. The mean coronal obliquity of the femoral tunnel was significantly lower in group 1 than in group 2 (42.5° ± 6.1° vs 49.3° ± 7.2°, respectively; P = .001), but the mean sagittal obliquity was similar between the 2 groups (41.9° ± 6.1° vs 43.3° ± 5.4°, respectively; P = .303). The mean area of the tunnel orifice was significantly greater in group 1 than in group 2 (11.6 ± 1.4 × 9.2 ± 1.6 mm vs 10.3 ± 1.1 × 9.1 ± 1.4 mm, respectively; P = .013). CONCLUSION: The modified transtibial technique for SB ACL reconstruction showed good clinical results and anatomic placement of the femoral tunnel, similar with those of the AM portal technique.