Accelerated degeneration of the discoid lateral meniscus after medial opening wedge high tibial osteotomy.

PURPOSE: This study was undertaken to report clinical outcomes after high tibial osteotomy (HTO) in patients with a discoid lateral meniscus and to determine (1) whether discoid lateral meniscus degeneration by magnetic resonance imaging (MRI) progresses after HTO and (2) whether this progression adversely affects clinical results. METHODS: The records of 292 patients (292 knees) who underwent medial opening HTO were retrospectively reviewed, and discoid types and grades of lateral meniscus degeneration as determined by MRI were recorded preoperatively. Of the 292 patients, 17 (5.8%) had a discoid lateral meniscus, and postoperative MR images were obtained at least 2 years after HTO for 15 of these 17 patients. RESULTS: American Knee Society (AKS) pain, knee and function scores significantly improved in the 15 patients after surgery (p < 0.001). Eight (53%) had an incomplete and 7 (47%) had a complete discoid lateral meniscus. By preoperative MRI, the distribution of meniscal degeneration was as follows: grade 1, 4 patients; grade 2, 7 patients; and grade 3, 4 patients. At the final follow-up, the distribution of degeneration was as follows: grade 1, 2 patients; grade 2, 5 patients; and grade 3, 8 patients. Two patients with grade 3 degeneration who did not undergo partial meniscectomy showed tear progression. Thus, 8 of the 15 patients (53%) experienced progressive discoid meniscal degeneration after HTO. Median AKS pain score was significantly lower in the progression group than in the non-progression group (40 vs 45, respectively). CONCLUSION: The results of this study suggest that increased load on the lateral compartment after HTO can accelerate discoid lateral meniscus degeneration by MRI and caution that when a discoid lateral meniscus is found by preoperative MRI, progressive degeneration may occur after HTO and clinical outcome may be adversely affected. LEVEL OF EVIDENCE: Therapeutic study, Level IV.

Femoral graft-tunnel angles in posterior cruciate ligament reconstruction: analysis with 3-dimensional models and cadaveric experiments.

PURPOSE: The purpose of this study was to compare four graft-tunnel angles (GTA), the femoral GTA formed by three different femoral tunneling techniques (the outside-in, a modified inside-out technique in the posterior sag position with knee hyperflexion, and the conventional inside-out technique) and the tibia GTA in 3-dimensional (3D) knee flexion models, as well as to examine the influence of femoral tunneling techniques on the contact pressure between the intra-articular aperture of the femoral tunnel and the graft. MATERIALS AND METHODS: Twelve cadaveric knees were tested. Computed tomography scans were performed at different knee flexion angles (0°, 45°, 90°, and 120°). Femoral and tibial GTAs were measured at different knee flexion angles on the 3D knee models. Using pressure sensitive films, stress on the graft of the angulation of the femoral tunnel aperture was measured in posterior cruciate ligament reconstructed cadaveric knees. RESULTS: Between 45° and 120° of knee flexion, there were no significant differences between the outside-in and modified inside-out techniques. However, the femoral GTA for the conventional inside-out technique was significantly less than that for the other two techniques (p<0.001). In cadaveric experiments using pressure-sensitive film, the maximum contact pressure for the modified inside-out and outside-in technique was significantly lower than that for the conventional inside-out technique (p=0.024 and p=0.017). CONCLUSION: The conventional inside-out technique results in a significantly lesser GTA and higher stress at the intra-articular aperture of the femoral tunnel than the outside-in technique. However, the results for the modified inside-out technique are similar to those for the outside-in technique.

Prognostic factors of arthroscopic pull-out repair for a posterior root tear of the medial meniscus.

BACKGROUND: Repair of a posterior root tear of the medial meniscus (MRT) decreases peak contact pressure by restoring hoop tension and is expected to prevent progression to osteoarthritis. PURPOSE: The purposes of this study were (1) to report the clinical and magnetic resonance imaging (MRI) results of arthroscopic pull-out repair of the MRT and (2) to identify prognostic factors of poor outcome. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Fifty-one patients (47 women, 4 men) who underwent arthroscopic pull-out repair of the MRT by a single surgeon were enrolled. Mean follow-up after surgery was 33 months (range, 24-44 months). To identify factors affecting final outcome, patient-specific factors, such as gender, age, body mass index, meniscus extrusion, extrusion increase, subchondral edema, degree of varus alignment (<5° or >5°), and cartilage status in the medial compartment (Outerbridge grade 1 or 2 lesion vs grade 3 or 4 lesion), were investigated. Final clinical outcomes were determined using a visual analog scale (VAS) for pain and patient satisfaction scores, American Knee Society (AKS) scores, and Lysholm scores, and MRI outcomes were determined by evaluating meniscus extrusion and articular cartilage status. Multiple regression analysis was performed to identify variables that independently affected clinical and MRI-determined outcomes. RESULTS: All clinical outcome measures significantly improved after surgery. Patients with Outerbridge grade 3 or 4 chondral lesions had poorer results than those with grade 1 or 2 lesions in terms of AKS function and Lysholm scores. Patients with varus alignment of >5° had poorer results than those with varus alignment of <5° in terms of VAS satisfaction, AKS function, and Lysholm scores. Mean meniscus extrusion increased from 3.6 mm preoperatively to 5.0 mm postoperatively. Chondral lesions progressed in 3 (9.7%) of 31 patients. Preoperative meniscus extrusion was found to be positively correlated with final extrusion. CONCLUSION: At a mean follow-up of 33 months after pull-out repair, extrusion of the meniscus was found to have progressed. Nevertheless, this technique provided patients with a clinical benefit. Outerbridge grade 3 or 4 chondral lesions and varus alignment of >5° were found to independently predict an inferior clinical outcome.

The safe establishment of a transseptal portal in the posterior knee.

PURPOSE: The aims of this study were as follows: (1) to determine the dimensions of the posterior compartments and the location of the popliteal artery with regard to the posterior septum by magnetic resonance arthrography; (2) to assess the effect of demographic factors on the measurements taken; and (3) to find a safe means of establishing the transseptal portal. METHODS: Thirty magnetic resonance arthrographies taken in 90° of flexion were evaluated to simulate knee position during arthroscopic surgery. Coronal and axial images were obtained in positions parallel and perpendicular to the long axis of the tibia, respectively. The anterior-to-posterior dimensions of the posteromedial and posterolateral compartments and popliteal artery locations were measured in the safe zone to establish transseptal portals. These dimensions were measured in axial images corresponding to the mid-PCL level. RESULTS: The average anterior-to-posterior dimension was 11.7 ± 2.9 mm in the posteromedial compartment versus 7.9 ± 1.8 mm in the posterolateral compartment. The anterior-to-posterior dimension was consistently greater in the posteromedial compartment, and the average ratio of the two dimensions was 1.5 ± 0.3. The average posterior deviation of the popliteal artery from the PCL was 27.1 ± 4.8 mm. The popliteal artery was always located lateral to the septum, and the lateral deviation on averaged measured 10.2 ± 4.0 mm. CONCLUSIONS: The safe margin of the posteromedial compartment is consistently wider than that of the posterolateral compartment, and the popliteal artery is consistently located lateral to the posterior septum. Therefore, injury to the popliteal artery can be avoided when penetrating the septum lateral to medial direction, even if the penetrating stick slips posteriorly. LEVEL OF EVIDENCE: Diagnostic study, Level IV.

Arthroscopic pullout repair of posterior root tear of the medial meniscus: the anterior approach using medial collateral ligament pie-crusting release.

Posterior root tears of the medial meniscus are frequently encountered and should be repaired if possible to prevent osteoarthritis of the medial compartment. Various surgical techniques have been proposed to repair posterior root tears. The anterior arthroscopic approach can cause an iatrogenic chondral injury due to the narrow medial joint space. The posterior approaches might be technically unfamiliar to many surgeons because they require the establishment of a posteromedial or trans-septal portal. This paper describes the medial collateral ligament pie-crusting release technique for arthroscopic double transosseous pullout repair of posterior root tears of the medial meniscus through the anterior approach to provide the good visualization of the footprint and sufficient working space.

Is correctional osteotomy crucial in primary varus knees undergoing anterior cruciate ligament reconstruction?

BACKGROUND: Valgus high tibial osteotomy (HTO) has been recommended for ligament stability and enhanced function after anterior cruciate ligament (ACL) reconstruction in varus-angulated knees. However, it is not clear whether HTO should be performed in patients undergoing ACL reconstruction who have primary varus knees without medial compartment arthrosis. QUESTIONS/PURPOSES: We therefore asked whether stability and function differed in patients having ACL reconstruction with differing degrees of preoperative alignment. PATIENTS AND METHODS: We retrospectively reviewed 201 patients who had primary, single-bundle ACL reconstructions with primary varus knees based on the preoperative mechanical axis deviation (MAD) on preoperative standing hip-knee-ankle radiographs. Patients were categorized into four groups according to the MAD: Group 1: 0 mm to 4 mm, Group 2: 5 mm to 9 mm, Group 3: 10 mm to 14 mm, and Group 4: greater than 15 mm. A total of 201 patients, 67 in Group 1, 53 in Group 2, 38 in Group 3, and 43 in Group 4, were assessed. Ligament stability was determined with the Lachman test, pivot shift test, and KT 2000™ arthrometer. Functional scores were assessed using the Lysholm score and the International Knee Documentation Committee (IKDC) score. The minimum followup was 24 months (mean, 45 months; range, 24-96 months). RESULTS: We observed no differences in the side-to-side KT 2000™ measurements, Lysholm score, or IKDC functional scores based on the preoperative MAD. CONCLUSIONS: The stability and functional scores after ACL reconstruction were not adversely altered by primary varus alignment. Thus, if there is no medial compartment arthritis or varus thrust, we do not believe a correctional tibial osteotomy is crucial in primary varus knees undergoing ACL reconstruction.

Anterolateral transtibial posterior cruciate ligament reconstruction combined with anatomical reconstruction of posterolateral corner insufficiency: comparison of single-bundle versus double-bundle posterior cruciate ligament reconstruction over a 2- to 6-year follow-up.

BACKGROUND: There is a paucity of clinical studies comparing single- and double-bundle posterior cruciate ligament (PCL) reconstruction combined with a posterolateral corner reconstruction. PURPOSE: To compare the clinical outcomes of single- and double-bundle transtibial PCL reconstruction combined with reconstruction of the lateral collateral ligament and popliteus tendon for posterolateral corner insufficiency. STUDY DESIGN: Cohort study; Level of evidence 3. METHODS: The study population consisted of 42 patients for whom a minimum of 2 years of follow-up data were available. The authors compared the clinical outcomes of 2 surgical techniques: a single-bundle technique (23 patients) and a double-bundle technique (19 patients), each combined with reconstruction of the lateral collateral ligament and popliteus tendon for posterolateral corner insufficiency. RESULTS: There was no significant difference between the single- and double-bundle groups in mean side-to-side difference of posterior translation as measured with Telos stress radiography (4.2 ± 1.7 vs 3.9 ± 1.6 mm; P = .628). Rates of residual increased laxity greater than 5 mm were 22% in the single-bundle group and 21% in the double-bundle group. Regarding posterolateral rotatory instability, there were no differences between the 2 groups in mean side-to-side difference in the dial test (5.3° ± 2.7° vs 5.1° ± 2.4° at 30° of flexion [P = .800]; 6.7° ± 2.7° vs 6.7° ± 2.4° at 90° of flexion [P = .917]) or in varus stress radiography (1.2 ± 1.2 vs 1.3 ± 1.4 mm; P = .722). The Lysholm knee scores were 85.7 ± 7.6 in the single-bundle group and 87.7 ± 7.3 in the double-bundle group, and there was no significant difference between them (P = .392). There was also no difference between the groups in International Knee Documentation Committee knee score (P = .969); from this, the rates of abnormal and severely abnormal were 30% in the single-bundle group and 26% in the double-bundle group. CONCLUSION: In this series, double-bundle PCL reconstruction combined with posterolateral corner reconstruction did not appear to have advantages over single-bundle PCL reconstruction combined with posterolateral corner reconstruction with respect to the clinical outcomes or posterior knee stability.

Arthroscopic treatment for limitation of motion of the elbow: the learning curve.

PURPOSE: The aim of this study was to demonstrate our learning curve in arthroscopic treatment for limitation of motion of the elbow. METHODS: To verify the surrogates for learning curve, operative time in 120 consecutive elbows were plotted by case number and the learning curve was illustrated by the best-fit curve. The study population was divided into eight consecutive blocks (15 patients per block) by observing a notable change in the learning from the curve. Mean operative time and mean improvement in motion and clinical score in each block were compared. RESULTS: Mean operative time decreased significantly from the first block to the second block (133-98). No further significant change was noted thereafter. Contrarily, no significant increase in motion improvement or clinical score improvement was identified but a significant decrease was found between the fourth and fifth block (47-36 and 30-24, respectively). Operative time was negatively correlated with preoperative range of motion (P=0.003). Clinical score improvement was also negatively correlated with preoperative range of motion (P<0.001). Motion improvement was more strongly correlated with preoperative range of motion (P<0.001). CONCLUSIONS: This study demonstrated a learning curve in which a significant decrease in operative time was shown after an initial 15 patients. Motion and clinical score improvement were not satisfactory surrogate for learning curve and found to be closely related to preoperative range of motion. Qualification of the learning curve for arthroscopic treatment for limitation of motion of the elbow provides a guide for surgeons assuming the expected time line to become proficient in this technique.

Iatrogenic suprascapular nerve injury after repair of type II SLAP lesion.

Suprascapular neuropathy after an arthroscopic repair of a SLAP lesion is theoretically possible, but it has been rarely reported. We present a case of suprascapular nerve injury at the spinoglenoid notch as a complication of an improperly inserted suture anchor after repair of a type II SLAP lesion. The diagnosis was confirmed by the magnetic resonance imaging findings and an electrodiagnostic study, and direct compression of the nerve was visualized under repeat arthroscopy. An anatomic study of the superior glenoid shows that the available bone stock of the superior glenoid rim for the anchor insertion is found to decrease posteriorly. During the repair of a SLAP lesion, surgeons should consider the possibility of an iatrogenic injury to the suprascapular nerve by an improperly inserted suture anchor.

A biomechanical comparison of 3 reconstruction techniques for posterolateral instability of the knee in a cadaveric model.

PURPOSE: The objective of this study was to compare the varus and external rotatory laxity of reconstructed knees by use of 3 different reconstruction techniques that address posterolateral instability of the knee: popliteus tendon (PT) and lateral collateral ligament (LCL) reconstruction, PT and popliteofibular ligament (PFL) reconstruction, and PFL and LCL reconstruction. METHODS: We divided 36 fresh-frozen cadaveric knees into 3 groups of 12, and each group was assigned to a reconstruction technique: PT-LCL reconstruction with the posterior tibialis tendon, PT-PFL reconstruction with the patellar tendon and bone (Warren technique), and PFL-LCL reconstruction with the semitendinosus tendon (Larson technique). Each specimen was fixed with an Ilizarov external fixator and mounted on a custom-designed apparatus that was made to measure posterolateral instability of the knee, that is, external rotatory and varus laxity in the intact state, after cutting, and in the postoperative state at every 30 degrees from 0 degrees to 90 degrees . RESULTS: There were no significant differences between the 3 techniques with external rotation and varus laxity in all specimens. CONCLUSIONS: PT-LCL reconstruction was comparable to the other 2 established techniques: PT-PFL reconstruction (Warren technique) and PFL-LCL reconstruction (Larson technique). However, the original strength of the native knee could not be achieved with any of the techniques. CLINICAL RELEVANCE: All techniques restored the posterolateral stability of the knee to near normal, with none of them being superior.

Does severity or specific joint laxity influence clinical outcomes of anterior cruciate ligament reconstruction?

UNLABELLED: It generally is believed generalized joint laxity is one of the risk factors for failure of anterior cruciate ligament (ACL) reconstruction. However, no consensus exists regarding whether adverse effects on ACL reconstruction are attributable to joint-specific laxity or are related to the severity of generalized joint laxity. We therefore asked whether knee stability and functional outcomes would be related to joint-specific laxity and would differ according to the severity of generalized joint laxity. The Beighton and Horan criteria were used to assess joint laxity in 272 subjects. All elements are added to give an overall joint laxity score ranging from 0 to 5. Knee translation did not increase in proportion to the severity of the generalized joint laxity. Patients with scores less than 4 showed similar knee stability. When all variables, including the severity of generalized joint laxity, were considered, only hyperextension of the knee independently predicted knee stability and function. In patients with knee hyperextension, a bone-patellar tendon-bone autograft provided superior stability and function compared with a hamstring tendon autograft. Our data suggest knee hyperextension predicts postoperative stability and function regardless whether patients have severe generalized joint laxity. LEVEL OF EVIDENCE: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

A combined transglenoid and suture anchor technique for bony Bankart lesions.

We present a modified hybrid technique that is a combination of a transglenoid and suture anchor technique. Three-dimensional CT reconstruction is indicated for patients with bony fragments larger than 10 mm. First, a transglenoid technique is performed to reduce the bony fragment and then a suture anchor technique is performed to achieve a stable fixation. This combined technique is a useful arthroscopic procedure for the easy reduction and stable fixation of bony Bankart lesions.

Is the transglenoid suture technique recommendable for recurrent shoulder dislocation? A minimum 5-year follow-up in 59 non-athletic shoulders.

The aim of this retrospective study is to compare the clinical outcomes following arthroscopic Bankart repair employing the transglenoid technique versus suture anchors in non-athletic shoulders of patients 30 years or older at the time of surgery. Fifty-nine consecutive patients who were available for a minimum of 5 years follow-up after arthroscopic Bankart repair were included. The transglenoid technique was employed in 27 patients whose age and follow-up period were 37 years (range 30-58) and 82 (range 61-109) months. Suture anchor was used in 32 patients whose age and follow-up period were 38 years (range 30-62) and 72 months (range 65-89). The Rowe scores of the transglenoid and suture anchor groups were 90 (range 35-100) and 90 (range 35-100), respectively, and there was no statistically significant difference between the two groups (p > 0.05). The Constant score of both groups was 92 (range 64-100) and 95 (range 62-100) without a significant difference (p > 0.05). Moreover, there were no significant differences between the recurrence rates (7%-transglenoid, 6%-suture anchor) (p > 0.05) and positive apprehension signs (7%-transglenoid, 3%-suture anchor) (p > 0.05). In non-athletes over 30-years-old, the results of the transglenoid technique in arthroscopic Bankart repair were comparable to those of the suture anchor. We suggest that the transglenoid technique is a viable alternative for older, non-athletic shoulder if the suture anchors are not available.

Factors affecting outcome after total knee arthroplasty in patients with diabetes mellitus.

PURPOSE: To compare the clinical outcome and complications following total knee arthroplasty (TKA) in diabetic and non-diabetic patients, and to identify diabetes-related risk factors for negative outcomes. MATERIALS AND METHODS: 222 primary TKAs in patients with diabetes were evaluated using Knee Society scores and Hospital for Special Surgery score. Postoperative complications were reviewed retrospectively. The mean follow-up was 53.2 months. The effect of diabetes-related factors and comparison with a matched control group were analyzed statistically. RESULTS: Significant improvements were noted in all the scores after TKA (p < 0.05). There was no statistical difference in clinical sores between the diabetic and non-diabetic patients. In multivariate analysis associating age, gender and body mass index with pain and knee score at the latest follow-up, the average knee scores in normal and overweight group were found to be significantly higher than those in the obese group. The diabetic patients had an increased overall incidence of postoperative complications (17.6%) compared with the control group (8.1%) (p < 0.05). Particularly, the rate of wound complications such as skin necrosis, bulla formation or erythema with drainage was higher in the diabetic group (p < 0.05). Diabetes-related factors did not influence the incidence of complications. Associated diseases were the only significant risk factors correlated with wound complications and meniscal bearing dislodgement. CONCLUSION: Patients with diabetes can benefit from TKA, even though diabetic patients are at an increased risk for overall postoperative and wound complications. Preoperative factors such as obesity and associated diseases may adversely affect the clinical outcome of TKA in diabetic patients.