Anterior translation and rotational stability of anterior cruciate ligament-deficient knees during walking: speed and turning direction.

BACKGROUND: Anterior cruciate ligament (ACL) rupture is one of the most common injuries associated with the knee. After ACL injury, knee joint stability can be altered, resulting in abnormal loading during functional activities. Since ACL-deficient (ACLD) knees are also vulnerable to translational and rotational instability, patients need to be wary of certain motions encountered in daily life. The present study investigated the effect of walking speed and pivoting directional change during gait on knee joint kinematics of ACLD knees. We hypothesized that faster walking and crossover turning would induce severe kinematic changes. METHODS: Thirty-five patients (22 males and 13 females) having a unilateral isolated subacute ACLD knee (from 1 to 3 months after injury) and contralateral intact (CLI) knee participated in this study. Spatiotemporal parameters, three-dimensional (3D) knee joint angles, and anterior-posterior (AP) translation were obtained by a 3D high-speed motion-capturing system. The CLI knee of each patient served as the control. The calculated AP stability and knee joint angles were used to test the research hypothesis. Mixed two-way repeated measures analysis of variance was performed to clarify the effects of walking speed and pivoting direction with a significance of 0.05. When a significance of mean comparison was detected, a post hoc test was performed. RESULTS: Significant and consistent increased AP translation of the tibia relative to the femur at the whole stance phase of the gait cycle was evident in ACLD knees compared to CLI knees for normal and faster (20 % greater than normal) walking speeds. Faster walking speed did not induce significantly more anterior location of the tibia. In addition, ACLD knees were significantly less extended than CLI knees during a large portion of midstance. Although there was a consistent varus offset between the curves of ACLD and CLI knees, the difference did not reach statistical significance during the stance phase. Also, ACLD knees did not show any significant difference in tibial rotation compared to CLI knees during the entire stance phase of the gait cycle. For pivoting turns, ACLD knees showed significantly less extended and varus offset than CLI knees only during the cutting turn. ACLD knees exhibited less tibial internal rotation during the crossover turn and less tibial external rotation during the cutting turn than CLI knees. CONCLUSIONS: In ACLD knees, the tibia tended to shift more anteriorly and changed with less extension at walking. However, faster walking speed did not induce any significant difference compared with normal-speed walking. In addition, ACLD knees displayed kinematic changes during pivoting, but not the crossover turn.

Progression of osteoarthritis after double- and single-bundle anterior cruciate ligament reconstruction.

BACKGROUND: No consensus has been reached on the advantages of double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) over the single-bundle (SB) technique, particularly with respect to the prevention of osteoarthritis (OA) after ACLR. PURPOSE: To evaluate whether DB ACLR has any advantages in the prevention of OA or provides better stability and function after ACLR compared with the SB technique. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: A total of 130 patients with an ACL injury in one knee were prospectively randomized into a DB group (n = 65) or an SB group (n = 65). For the radiologic evaluation, we determined the degree of OA based on the Kellgren-Lawrence grade before the operation and at the time of the final follow-up and determined the number of patients with progression of OA more than one grade from pre- to postoperation. We evaluated the stability results using the Lachman and pivot-shift tests and stress radiography. We also compared the functional outcomes based on the Lysholm knee score, Tegner activity score, and International Knee Documentation Committee (IKDC) subjective scale. RESULTS: Six patients (4 in the DB group and 2 in the SB group) suffered graft failure during the follow-up and had ACL revision surgery (P = .06). A total of 112 patients were observed for a minimum of 4 years (DB group, n = 52; SB group, n = 60). Five patients (9.6%) in the DB group and 6 patients (10%) in the SB group had more advanced OA at the final follow-up (P = .75). All patients recovered full range of motion within 6 months from surgery. Stability results of the Lachman test, pivot-shift test, and the radiographic stability test failed to reveal any significant intergroup differences (P = .37, .27, and .67, respectively). In the pivot-shift result, the DB group had 4 patients with grade 2 and the SB group had 3 patients with grade 2 (P = .27). Clinical outcomes, including Lysholm knee and Tegner activity scores, were similar in the 2 groups. Statistical significance was achieved only for the IKDC subjective scale (78.2 in DB group vs 73.1 in SB group; P = .03). CONCLUSION: The DB technique, compared with SB, was not more effective in preventing OA and did not have a more favorable failure rate. Although the DB ACLR technique produced a better IKDC subjective scale result than did the SB ACLR technique, the 2 modalities were similar in terms of clinical outcomes and stability after a minimum 4 years of follow-up.

A comparative study of meniscectomy and nonoperative treatment for degenerative horizontal tears of the medial meniscus.

BACKGROUND: It is still debated whether a degenerative horizontal tear of the medial meniscus should be treated with surgery. HYPOTHESIS: The clinical outcomes of arthroscopic meniscectomy will be better than those of nonoperative treatment for a degenerative horizontal tear of the medial meniscus. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 102 patients with knee pain and a degenerative horizontal tear of the posterior horn of the medial meniscus on magnetic resonance imaging were included in this study between January 2007 and July 2009. The study included 81 female and 21 male patients with an average age of 53.8 years (range, 43-62 years). Fifty patients underwent arthroscopic meniscectomy (meniscectomy group), and 52 patients underwent nonoperative treatment with strengthening exercises (nonoperative group). Functional outcomes were compared using a visual analog scale (VAS) for pain, Lysholm knee score, Tegner activity scale, and patient subjective knee pain and satisfaction. Radiological evaluations were performed using the Kellgren-Lawrence classification to evaluate osteoarthritic changes. RESULTS: In terms of clinical outcomes, meniscectomy did not provide better functional improvement than nonoperative treatment. At the final follow-up, the average VAS scores were 1.8 (range, 1-5) in the meniscectomy group and 1.7 (range, 1-4) in the nonoperative group (P = .675). The average Lysholm knee scores at 2-year follow-up were 83.2 (range, 52-100) and 84.3 (range, 58-100) in the meniscectomy and nonoperative groups, respectively (P = .237). In addition, the average Tegner activity scale and subjective satisfaction scores were not significantly different between the 2 groups. Although most patients initially had intense knee pain with mechanical symptoms, both groups reported a relief in knee pain, improved knee function, and a high level of satisfaction with treatment (P < .05 for all values). Two patients in the meniscectomy group and 3 in the nonoperative group with Kellgren-Lawrence grade 1 progressed to grade 2 at the 2-year follow-up. CONCLUSION: There were no significant differences between arthroscopic meniscectomy and nonoperative management with strengthening exercises in terms of relief in knee pain, improved knee function, or increased satisfaction in patients after 2 years of follow-up.

Robotic-assisted TKA reduces postoperative alignment outliers and improves gap balance compared to conventional TKA.

BACKGROUND: Several studies have shown mechanical alignment influences the outcome of TKA. Robotic systems have been developed to improve the precision and accuracy of achieving component position and mechanical alignment. QUESTIONS/PURPOSES: We determined whether robotic-assisted implantation for TKA (1) improved clinical outcome; (2) improved mechanical axis alignment and implant inclination in the coronal and sagittal planes; (3) improved the balance (flexion and extension gaps); and (4) reduced complications, postoperative drainage, and operative time when compared to conventionally implanted TKA over an intermediate-term (minimum 3-year) followup period. METHODS: We prospectively randomized 100 patients who underwent unilateral TKA into one of two groups: 50 using a robotic-assisted procedure and 50 using conventional manual techniques. Outcome variables considered were postoperative ROM, WOMAC scores, Hospital for Special Surgery (HSS) knee scores, mechanical axis alignment, flexion/extension gap balance, complications, postoperative drainage, and operative time. Minimum followup was 41 months (mean, 65 months; range, 41-81 months). RESULTS: There were no differences in postoperative ROM, WOMAC scores, and HSS knee scores. The robotic-assisted group resulted in no mechanical axis outliers (> ± 3° from neutral) compared to 24% in the conventional group. There were fewer robotic-assisted knees where the flexion gap exceeded the extension gap by 2 mm. The robotic-assisted procedures took an average of 25 minutes longer than the conventional procedures but had less postoperative blood drainage. There were no differences in complications between groups. CONCLUSIONS: Robotic-assisted TKA appears to reduce the number of mechanical axis alignment outliers and improve the ability to achieve flexion-extension gap balance, without any differences in clinical scores or complications when compared to conventional manual techniques.

No better flexion or function of high-flexion designs in Asian patients with TKA.

BACKGROUND: Recently, high-flexion PCL-retaining (CR) and -substituting (PS) knee prostheses were designed to allow greater and safer flexion after TKA. However, the advantages of high-flexion TKA over standard design have been debated in terms of early maximal flexion. A recent study reported a high incidence of early loosening of the femoral component related to the deep flexion provided by high-flexion PS TKA. QUESTIONS/PURPOSES: We determined whether high-flexion fixed bearing CR and PS prostheses would provide (1) a better flexion, (2) a better function, and (3) a higher incidence of radiographic loosening than TKA performed using standard fixed bearing CR prostheses in Asian patients. METHODS: From a total of 182 patients with primary unilateral TKA, we retrospectively reviewed 137 TKAs: 47 with high-flexion CR, 42 with high-flexion PS, and 48 with standard CR designs. ROM, Knee Society scores, and WOMAC scores were evaluated and compared among the three groups. Radiographically, we assessed radiolucent zones and component loosening. Minimum followup was 5 years (mean, 6.2 years; range, 5-8 years). RESULTS: We found no differences among the three groups in mean maximal flexion (high-flexion CR: 135°; high-flexion PS: 134°; standard CR: 136°), Knee Society scores, and WOMAC scores at last followup. Also, there were no differences among the three groups in terms of radiolucent lines around the prosthesis. No patient in any group had loosening of the femoral component. CONCLUSIONS: The high-flexion CR or PS design had no advantages over the standard CR design with respect to ROM, clinical scores, and radiolucent lines around the femoral or tibial component after 5 years' followup.

Comparison of high tibial osteotomy and unicompartmental knee arthroplasty at a minimum follow-up of 3 years.

The purpose of this study was to compare clinical outcomes including return to recreational activities (cycling, swimming, exercise walking, dancing, jogging, and mountain climbing) after opening-wedge high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA). Clinical outcomes were assessed using Tegner activity scores, ranges of motion, and Lysholm knee scores. In both groups, the number of patients participating in recreational activities was significantly reduced after surgery, but without a significant intergroup difference (1.3 activities in HTO group and in 1.6 activities in UKA group). Average Tegner activity scale scores, ranges of motion, and Lysholm knee scores did not show significant differences between the 2 groups. This study identified no significant differences between HTO and UKA for medial unicompartmental osteoarthritis in terms of return to recreational activity and short-term clinical outcomes.

Accuracy and safety of free-hand pedicle screw fixation in age less than 10 years.

BACKGROUND: Pedicle screws are being used commonly in the treatment of various spinal disorders. However, use of pedicle screws in the pediatric population is not routinely recommended because of the risk of complications. The present study was to evaluate the safety of pedicle screws placed in children aged less than 10 years with spinal deformities and to determine the accuracy and complication (early and late) of pedicle screw placement using the postoperative computed tomography (CT) scans. MATERIALS AND METHODS: Thirty one patients (11 males and 20 females) who underwent 261 pedicle screw fixations (177 in thoracic vertebrae and 84 in lumbar vertebrae) for a variety of pediatric spinal deformities at a single institution were included in the study. The average age of patients was 7 years and 10 months. These patients underwent postoperative CT scan which was assessed by two independent observers (spine surgeons) not involved in the treatment. RESULTS: Breach rate was 5.4% (14/261 screws) for all pedicles. Of the 177 screws placed in the thoracic spine, 13 (7.3%) had breached the pedicle, that is 92.7% of the screws were accurately placed within pedicles. Seven screws (4%) had breached the medial pedicle wall, 4 screws (2.3%) had breached the lateral pedicle wall and 2 screws (1.1%) had breached the superior or inferior pedicle wall respectively. Of the 84 screws placed in the lumbar spine, 83 (98.8%) screws were accurately placed within the pedicle. Only 1 screw (1.2%) was found to be laterally displaced. In addition, the breach rate was found to be 4.2% (11/261 screws) with respect to the vertebral bodies. No neurological, vascular or visceral complications were encountered. CONCLUSIONS: The accuracy of pedicle screw placement in pedicles and vertebral bodies were 94.6% and 95.8% respectively and there was no complication related to screw placement noted until the last followup. These results suggest that free-hand pedicle screw fixation can be safely used in patients younger than 10 years to treat a variety of spinal disorders.

Posterior tibial slope in medial opening-wedge high tibial osteotomy: 2-D versus 3-D navigation.

Although opening-wedge high tibial osteotomy (HTO) is used to correct deformities, it can simultaneously alter tibial slope in the sagittal plane because of the triangular configuration of the proximal tibia, and this undesired change in tibial slope can influence knee kinematics, stability, and joint contact pressure. Therefore, medial opening-wedge HTO is a technically demanding procedure despite the use of 2-dimensional (2-D) navigation. The authors evaluated the posterior tibial slope pre- and postoperatively in patients who underwent navigation-assisted opening-wedge HTO and compared posterior slope changes for 2-D and 3-dimensional (3-D) navigation versions. Patients were randomly divided into 2 groups based on the navigation system used: group A (2-D guidance for coronal alignment; 17 patients) and group B (3-D guidance for coronal and sagittal alignments; 17 patients). Postoperatively, the mechanical axis was corrected to a mean valgus of 2.81° (range, 1°-5.4°) in group A and 3.15° (range, 1.5°-5.6°) in group B. A significant intergroup difference existed for the amount of posterior tibial slope change (Δ slope) pre- and postoperatively (P=.04).Opening-wedge HTO using navigation offers accurate alignment of the lower limb. In particular, the use of 3-D navigation results in significantly less change in the posterior tibial slope postoperatively than does the use of 2-D navigation. Accordingly, the authors recommend the use of 3-D navigation systems because they provide real-time intraoperative information about coronal, sagittal, and transverse axes and guide the maintenance of the native posterior tibial slope.

Patellofemoral alignment and anterior knee pain after closing- and opening-wedge valgus high tibial osteotomy.

PURPOSE: The purpose of this study was to compare the clinical and radiographic outcomes of opening- and closing-wedge valgus high tibial osteotomy (HTO) for the treatment of medial unicompartmental knee osteoarthritis with a minimum follow-up of 3 years, with a focus on patellofemoral alignment and anterior knee pain. METHODS: We performed a retrospective comparison of 50 patients who underwent closing-wedge HTO and 50 patients who underwent opening-wedge HTO for isolated medial joint arthritis of the knee with varus deformity. All patients were evaluated and the 2 study groups were compared after a minimum follow-up of 3 years with a focus on patellofemoral alignment, patellofemoral osteoarthritis, and anterior knee pain while climbing stairs. RESULTS: Patellar alignment (patellar tilt and lateral patellar displacement) was not significantly different in the 2 groups either preoperatively or at follow-up. Furthermore, there were no significant differences in the extent of patellofemoral arthritis and incidence of anterior knee pain at follow-up between the 2 groups. In addition, no significant intergroup difference was found in terms of the incidence of anterior knee pain (28% in closing-wedge group and 32% in opening-wedge group at follow-up). CONCLUSIONS: The results of closing- and opening-wedge valgus HTO were not found to be significantly different with respect to patellar alignment, osteoarthritis of the patellofemoral joint, or anterior knee pain. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

The Efficacy and Persistence of Selective Nerve Root Block under Fluoroscopic Guidance for Cervical Radiculopathy.

STUDY DESIGN: Retrospective study. OBJECTIVES: To investigate the outcomes of fluoroscopically guided selective nerve root block as a nonsurgical treatment for cervical radiculopathy. OVERVIEW OF LITERATURE: Only a few studies have addressed the efficacy and persistence of cervical nerve root block. METHODS: This retrospective study was conducted on 28 consecutive patients with radicular pain due to cervical disc disease or cervical spondylosis. Myelopathy was excluded. Cervical nerve root blocks were administered every 2 weeks, up to 3 times. Outcomes were measured by comparing visual analogue scale (VAS) scores, patient satisfaction, and medication usage before the procedure and at 1 week and 3, 6, and 12 months after the procedure. In addition, complications associated with the procedure and need for other treatments were evaluated. RESULTS: The average preoperative VAS score was 7.8 (range, 5 to 10), and this changed to 2.9 (range, 1 to 7) at 3 months and 4.6 (range, 2 to 7) at 12 months. Patient satisfaction was 71% at 3 months and 50% at 12 months. Five patients used medication at 3 months, whereas 13 used medication at 12 months. Average symptom free duration after the procedure was 7.8 months (range, 1 to 12 months). Two patients were treated surgically. Only two minor complications were noted; transient ptosis with Horner's syndrome and transient causalgia. CONCLUSIONS: Although selective nerve root block for cervical radiculopathy is limited as a definitive treatment, it appears to be useful in terms of providing relief from radicular pain in about 50% of patients at 12 months.

Comparative study of stability after total knee arthroplasties between navigation system and conventional techniques.

The aim of this study was to evaluate the stability of mediolateral laxity in extension and anteroposterior laxity in 90 degrees of flexion using stress radiographs, modified Hospital for Special Surgery scores, and range of motion of total knee arthroplasties (TKAs) performed using a navigation system (navigation-assisted group, 42 knees) after a minimum 1-year follow-up and to compare them with those of a conventional TKA (conventional group, 44 knees) using a gap technique. The mean medial laxities were 3.5 degrees in the navigation-assisted group and 4.0 degrees in the conventional group, and the mean lateral and anteroposterior laxities were 4.4 degrees and 4.2 degrees in 7.1 and 7.0 mm, respectively. These results showed no significant differences between the 2 groups. Thus, we concluded that there is no significant difference between navigation-based and conventional techniques in terms of TKA stability. In addition, no significant differences were found between the 2 groups in modified HSS scores or range of motion.