Medial Joint Space Opening Research Articles

The Inside-Out Technique of Deep Medial Collateral Ligament Release Could Provide Good Visualization during Knee Arthroscopy

During knee arthroscopy, clear vision of the intra-articular structures is essential. Two techniques have been described to aid in visualization by releasing the medial collateral ligament (MCL). The outside-in technique remains the most widely used, but injury to the saphenous nerve is one of the potential risks when performing this technique. On the other hand, the inside-out techniques for releasing the deep MCL (dMCL) tend to be safer since the procedure was done under direct visualization through an anteromedial portal. This study was a retrospective case series of 22 patients who underwent the dMCL release using an inside-out technique. The outcomes reported are medial joint space opening, neurovascular injury, and residual morbidities such as pain and valgus knee instability after the procedure.

MCL internal brace does not fully recapitulate normal MCL function in valgus stress.

The null hypothesis is that there would be no difference in medial gapping under valgus load between the intact MCL and the ruptured MCL with an internal brace in place. Eight pairs of cadaver knees were used (16 knees). Alternating sides, one knee from each pair was used for one of two "internal brace" constructs. The constructs involved different methods of fixation for securing FiberTape (Arthrex, Naples, FL) to both the femur and tibia in an effort to brace the MCL. The knees were then subjected to valgus stress by applying 10Nm of torque with the knee at 20 degrees of flexion. The amount of medial joint space opening was measured on radiographs. The stress testing was conducted with three MCL states: intact, grade 2 tear, and grade 3 tear. In the Construct I specimens, gapping increased from 0.7mm with the MCL intact to 1.1mm with grade 2 tearing (p < 0.01), and to 1.3mm with grade 3 tearing (p < 0.01). In the Construct II specimens, gapping increased from 0.7mm with the MCL intact to 1.0mm with grade 2 tearing (p < 0.01), and to 1.1mm with grade 3 tearing (n.s.). Construct I specimens failed primarily at the femoral attachment. All Construct II specimens survived the valgus stress testing. Construct I did not maintain tension. Construct II did maintain tension during application of valgus load, but did not restore valgus opening to the intact state. It is important for clinicians who are considering using this commercially available technique to be aware of how the construct performs under valgus stress testing compared to the intact MCL.

OUTCOME OF PROXIMAL FIBULAR OSTEOTOMY IN ISOLATED MEDIAL COMPARTMENT OSTEOARTHRITIS OF KNEE: A COMPARATIVE STUDY.

Aim: Outcome of Proximal Fibular Osteotomy in isolated medial compartment Osteoarthritis of Knee.&#x0D; Material and Methods: The present study was conducted in the department of Orthopedics Jawaharlal Nehru Medical College, Bhagalpur from july 2018 to jan 2019. 36 patients amounting to 50 knee joints (male and female between 40-60 years age group) with medial compartment OA Knee were recruited. Medial joint spaces along-with visual analogue score for pain were recorded pre-operative, immediate post-operative and at final follow up.&#x0D; Result: Significant improvement in mean visual analogue pain score (VAS), from 7.02 preoperative to 3.39 at the final follow up was observed (p-value &lt;0.001). Medial joint space opening from 1.01 to 4.11 at final follow up was observed.&#x0D; Conclusion: The objectives as well as functional outcome after proximal fibular osteotomy were satisfactory.&#x0D; Keywords: Medial compartment Osteoarthritis Knee, PFO

Injured vs. uninjured elbow opening on clinical stress radiographs and its relationship to ulnar collateral ligament injury severity in throwers

Stress radiography measures medial joint space opening of the elbow, but its value in the management of throwing athletes is unclear. The purpose of this study was to analyze the relationship between medial joint opening (gapping and excess opening) and ulnar collateral ligament (UCL) injury severity on magnetic resonance imaging, as well as to explore factors related to the unexpected finding of a greater opening of the uninjured elbow compared with the injured elbow (negative excess opening) with valgus stress radiography. Medial joint space measurements were independently performed by 2 raters in a clinical series of 74 patients evaluated with standardized valgus stress radiography as part of their clinical workup for throwing-related medial elbow pain. Demographic data were collected by chart review, and UCL injury severity was classified based on available imaging into intact UCLs, partial-thickness tears of the anterior bundle, or full-thickness tears of the anterior bundle. Joint gapping was related to UCL injury severity (P = .003), and group-level comparison showed a difference among tear severity groups (P = .050). Excess opening was not significantly related to UCL injury severity (P = .109). A negative excess opening was observed in 22% of patients, but no factors corroborating guarding or a mechanical explanation were significant for a decreased medial joint opening of the injured elbow compared with the uninjured elbow. Medial joint gapping was correlated to UCL injury severity in throwing athletes with medial elbow pain and a clinical suggestion of UCL injury, but no association between injury severity and excess opening was observed in this clinical series, which may limit the usefulness of stress radiography in the clinical workup of throwing athletes.

Proximal Fibular Osteotomy–A Novel Technique for Decompression of Isolated Medial Compartment Osteoarthritis Knee

Introduction: Proximal Fibular Osteotomy (PFO) is removing 1-1.5 cm of FIBULA, 7 to 10 cm below its head, which provides symptomatic relief from pain of medial compartment Osteoarthritis (OA) knee. It is a procedure wherein we remove Proximal part of fibula to stop mechanical axis of knee going into further varus and hence putting a stop to progression of disease. The aim of the study was to observe and study the resultsin patients of isolated medial compartment Osteoarthritis of Knee,treated by Proximal Fibular Osteotomy. Material and Method: The study was conducted on 36 patients amounting to 50 knee joints (male and female between the age of 50-70 years) with medial compartment OA Knee. Patients were followed up till 6 months. Medial and lateral joint space along-with visual analogue score for pain were recorded preoperative, immediate post-operative and at final follow up. Result: Significant improvement in mean visual analogue pain score (VAS), from 7.32 + 0.98 preoperative to 2.72 + 1.20 at the final follow up was observed (p-value <0.001). Medial joint space opening from 1.17 + 0.29 to 4.07 + 0.69 at final follow up was observed. American knee society score was divided into 2 subsets, knee score and functional score. Both of them showed significant improvements from 39.72 + 3.47 and 44.20 + 8.47 (pre-operative) to 86.58 + 10.79 and 84.60 + 8.38 respectively, at final follow up (p-value < 0.001). Conclusion: The objective as well as functional outcome after proximal fibular osteotomy were satisfactory. With correct patient selection and meticulous adherence to basics, Proximal fibular osteotomy offers an excellent alternative to tedious and extensive procedures like High tibial osteotomy (HTO) and Unicompartmental Knee Arthroplasty (UKA). It is specially enthralling in country like ours where everyone cannot afford expensive surgeries and are forced to live a life of misery and morbidity.

Difference Between USI Humeroulnar Medial Joint Space Measurements Using Gravity-induced Vs. 3kg External Load Valgus Forces

PURPOSE: Injuries of the ulnar collateral ligament (UCL) are a common pathology in overhead athletes. Ultrasound imaging is becoming a more common diagnostic tool to diagnose UCL pathology. Ultrasound imaging protocols have been described using external mechanical valgus forces to evaluate medial joint space (MJS) opening as an indicator of joint instability and UCL insufficiency. However, this external mechanical force is often poorly tolerated by athletes with acute injuries. A gravity induced valgus force is often better tolerated, however this method may potentially result in lesser joint space opening. The purpose of this pilot study was to examine differences in joint space opening measurements between these two methods of applying valgus force while performing ultrasound imaging. METHODS: Nine asymptomatic NCAA Division I collegiate baseball pitchers (age 20.1 ± 1.3 yrs) participated in this study. Ultrasound images were obtained of the MJS on the participant’s throwing arm using a GE LOGIQ e ultrasound unit. Participants were placed supine with elbow position at 30 degrees, with a wedge placed underneath the humerus creating a gravity induced valgus force on the MJS. Ultrasound imaging measurements to evaluate MJS opening were performed from the apex of the trochlea to the apex of the ulna. A 3-kg valgus force, as measured by a hand-held dynamometer, was applied 20 cm distal to the medial epicondyle, and the imaging measurement was repeated. A paired t-test was performed to evaluate differences in joint space measurements between the two test protocols. RESULTS: There was no significant difference between the MJS measurements (mean difference .005cm, t = -.743, p= .479) using the gravity-induced valgus method (mean opening .441cm, SD .074cm) and the 3kg external force method (mean opening .446cm, SD .071cm). CONCLUSIONS: The results of this pilot study indicate that a gravity induced valgus force during ultrasound imaging of the UCL and MJS may yield similar joint opening compared to a mechanically induced 3kg external force. As external valgus force is often poorly tolerated in the presence of acute injury, gravity induced force may provide for an alternate method of evaluating medial joint space opening. Further research is recommended using larger sample size and symptomatic populations.

Is Shoulder Joint Rom Or Ucl Thickness A Predictor Of Medial Elbow Joint Space?

UCL injuries among baseball athletes are an extremely common pathology. It is well documented that baseball athletes typically exhibit an increase in shoulder external rotation range of motion (ERRM) and a decrease in internal rotation range of motion (IRRM) while maintaining total rotational range of motion (TROM). Loss of TROM and ERRM may be associated with increased risk for UCL injury. Ultrasound imaging allows clinicians to evaluate UCL thickness and medial joint space (MJS) opening non-invasively. PURPOSE:To examine if shoulder joint motion (ERRM, IRRM, TROM), or the thickness of the UCL at the mid substance and apex of trochlea predicts medial elbow joint space (MJS) in asymptomatic collegiate baseball pitchers. METHODS:Twenty-nine NCAA Division I pitchers participated in this follow-up study. Ultrasound images were obtained of the MJS and UCL on the participant’s throwing arm using a GE LOGIQ e ultrasound unit. Participants were placed supine with a wedge placed underneath their pitching hand to maintain elbow position at 30 degrees. A 3 kg valgus force, as measured by a hand-held dynamometer, was applied 20 cm distal to the medial epicondyle. Ligament thickness measurements were performed at the mid-substance of UCL and at the apex of the trochlea. Imaging measurements to evaluate MJS opening were performed from the apex of the trochlea to the apex of the ulna. Standard goniometric procedures were performed with the athlete in a supine position to obtain ERRM, IRRM, and TROM values. Three stepwise linear multiple regression analyses were performed to determine if shoulder ROM or UCL thickness measures of the mid-substance and apex of the trochlea could predict MJS. RESULTS:Shoulder joint range of motion were not able to significantly predict MJS [R2= .05, F (2,25) = 0.58, p=0.56,]. UCL thickness at the mid-substance [R2= .04, F (1,25) = 0.10, p=0.76], and at apex of the trochlea [R2= .00, F (1, 25) = 0.03, p=0.95] were not able to significantly predict MJS. CONCLUSIONS:Results further supported prior research that shoulder ROM did not predict MJS, and new to this study, UCL thickness measured at two points were unable to predict MJS in asymptomatic baseball pitchers. Further research is recommended to perform multiple imaging sessions throughout the competitive season to further determine predictors of UCL injuries.

Effect of posterior oblique ligament repair on rotational stability of knee joint

To investigate effect of posterior oblique ligament (POL) repair on the rotational stability of the knee joint for the medial collateral ligament (MCL) combined with anterior cruciate ligament (ACL) ruptures. The clinical data of 50 patients (50 knees) with grade-3 MCL-ACL combined injuries who met the selection criteria between January 2013 and December 2015 were retrospectively analyzed. All ACLs were reconstructed with autogenous tendon and the superficial and deep layers of MCLs were sutured; then, POLs were also sutured in 25 patients of repair group and only received conservation treatment postoperatively in 25 patients of conservation group. There was no significant difference in gender, age, disease duration, and preoperative KT-1000 measuring, medial joint space opening, International Knee Documentation Committee (IKDC) score, visual analogue scale (VAS) score, and knee range of motion between the two groups ( P>0.05). All incisions of the two groups healed by first intention, no surgical related complications occurred. All patients were followed up, with follow-up time of 28-56 months (mean, 38.1 months) in repair group and 26-55 months (mean, 29.1 months) in conservation group. At last follow-up, the IKDC score, VAS score, KT-1000 measuring, medial joint space opening, and knee range of motion significantly improved in the two groups when compared with preoperative ones ( P<0.05); but there was no significant difference between the two groups ( P>0.05). The Slocum test showed that there was no instability of the anterior medial rotation in the two groups. The POL repair can't obtain more medial stability after ACL reconstruction and MCL repair (superficial and deep layers) for patients who have MCL-ACL combined injuries.

Percutaneous Medial Ligament Reconstruction for Valgus Knee Instability

Injuries to stabilizing elements on the medial side of the knee are one of the most common knee ailments. Because of the good healing capacity of these structures, acute injuries are typically treated conservatively. However, valgus laxity near full extension can persist in some patients. This laxity may be the source of instability due to medial joint space opening, which then requires surgical treatment. Various procedures have been described that aim to reproduce the anatomy of the medial collateral ligament (MCL) and the posterior oblique ligament (POL), which work together to stabilize the medial aspect of the knee. However, these are complex open surgical procedures, technically demanding to achieve the favorable isometry, which prevent joint contracture or recurrence of laxity. The purpose of this study was to describe a short construct that minimizes the risk of secondary loss of tension and complies with the principle of favorable anisometry. The graft is positioned in the joint opening axis, between the deep bundle of the MCL and the POL.

Does Shoulder Joint ROM Predict Medial Elbow Joint Space and UCL Thickness?

Baseball athletes, especially pitchers, are prone to ulnar collateral ligament (UCL) injuries of the elbow. It is well documented that baseball athletes typically exhibit an increase in shoulder external rotation range of motion (ERRM) and a decrease in internal rotation range of motion (IRRM) while maintaining total rotational range of motion (TROM) in the throwing extremity. Furthermore, loss of TROM and ERRM may be associated with increased risk for UCL injury. Ultrasound imaging allows clinicians to evaluate UCL thickness and medial joint space (MJS) opening non-invasively. PURPOSE: To examine if shoulder joint motion (ERRM, IRRM, TROM), predicts medial elbow joint space (MJS) opening and UCL thickness in asymptomatic collegiate baseball pitchers at the start of the pre-season. METHODS: Nineteen asymptomatic NCAA Division I collegiate baseball pitchers (age 20.4 ± 1.45 yrs) participated in this study. Ultrasound images were obtained of the medial joint space and UCL on the participant’s throwing arm using a GE LOGIQ e ultrasound unit. Participants were placed supine with a wedge placed underneath their pitching hand to maintain elbow position at 30 degrees. A 3 kg valgus force, as measured by a hand held dynamometer, was applied 20 cm distal to the medial epicondyle. Ligament thickness measurements were performed at the mid-substance of UCL and at the apex of the trochlea. Imaging measurements to evaluate MJS opening were performed from the apex of the trochlea to the apex of the ulna. Standard goniometric procedures were performed with the athlete supine to obtain ERRM, IRRM, and TROM values. Three stepwise linear multiple regression analyses were performed to determine if shoulder joint motion could predict UCL thickness and MJS. RESULTS: Shoulder joint range of motion did not significantly predict MJS [R2 = .05, F (2,16) = 0.44, p=0.65,], UCL thickness at the mid-substance [R2 = .01, F (2,16) = 0.12, p=0.89], or UCL thickness at the apex of the trochlea [R2 = .04, F (2, 16) = 0.36, p=0.70]. CONCLUSIONS: Measures of shoulder joint ROM do not predict MJS or UCL thickness in asymptomatic baseball pitchers at the start of the season. Further research is recommended to perform multiple imagining sessions throughout the competitive season to further evaluate relationships between shoulder ROM and medial elbow structures.

The development and validation of a custom built device for assessing frontal knee joint laxity

IntroductionThis study reports the development and validation of a quantitative technique of assessing frontal knee joint laxity through a custom built device named KLICP. The objectives of this study were to determine: (i) the intra- and inter-rater reliability and (ii) the validity of the device when compared to real time ultrasound. MethodsTwenty-five participants had their frontal knee joint laxity assessed by the KLICP, by manual varus/valgus tests and by ultrasound. Two raters independently assessed laxity manually by three repeated measurements, repeated at least 48h later. Results were validated by comparing them to the medial and lateral joint space opening measured by the ultrasound. Intraclass correlation coefficients and standard error of measurement reliability were calculated. Pearson's correlation coefficients were calculated to determine the correlation between the KLICP and the joint space. ResultsIntra-rater reliability (intra-session) for each rater was good on both sessions (0.91–0.98), intra-rater reliability (inter-sessions) was moderate to good (0.62–0.87), and inter-rater reliability (intra-session) was good (0.75–0.80). There is low agreement for intra-rater (inter-session) and for inter-rater (intra-session) reliability. The KLICP measurement has a significant positive fair to moderate correlation to the ultrasound measurement at the left (r: 0.61, p: 0.01) and right (r: 0.48, p: 0.02) knee in the valgus direction and at the left (r: 0.51, p: 0.01) and right (r: 0.39, p: 0.05) knee in the varus direction. There is low agreement between the KLICP and the RTU. ConclusionsReliability and agreement was good only when measured for intra-rater, within session.

Does Superficial Medial Collateral Ligament Release in Open-Wedge High Tibial Osteotomy for Varus Osteoarthritic Knees Increase Valgus Laxity?

Background: Medial open-wedge high tibial osteotomy (OWHTO) requires the release of the superficial medial collateral ligament (sMCL). However, research on medial laxity among patients who undergo OWHTO is rare. Purpose: To evaluate the changes in medial laxity of the knee joint as related to the complete release of the sMCL through serial valgus stress radiographs in patients who underwent OWHTO. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 48 patients (54 knees) who received OWHTO and were followed for more than a year and for whom serial valgus stress radiography data were available were retrospectively reviewed. To assess the medial laxity of knee joint, medial joint space opening (MJO) was measured while valgus stress of 15 kgf was loaded on the knee joint. The MJO was measured before surgery, during surgery before release of the sMCL under anesthesia, after the release, and after fixing with a TomoFix plate following the opening of the osteotomy site, as well as 3, 6, and 12 months after surgery. Serially measured MJOs were analyzed to evaluate the changes of medial laxity. Results: The MJO significantly increased after the release of the sMCL (mean ± SD, 12.2 ± 1.2 mm) compared with before the release (9.0 ± 1.1 mm) (P < .001). The MJO measured after fixing with the TomoFix plate following the opening of the osteotomy site (9.2 ± 1.2 mm) was significantly decreased compared with that measured after the release of the sMCL and was not significantly different from the MJO measured before release of the sMCL. No significant difference was observed among MJOs that were measured 3, 6, and 12 months after surgery. Comparison of MJOs before and after surgery also showed no significant differences. Conclusion: Complete release of the sMCL during OWHTO increases the MJO. However, the MJO decreased to the level before sMCL release after fixing with the TomoFix plate following the opening of the osteotomy site. Medial laxity induced by the complete release of the sMCL can be recovered by opening the osteotomy site.

Anterior cruciate ligament and medial collateral ligament injuries.

The diagnosis and treatment of combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries have evolved over the past 30 years. A detailed physical examination along with careful review of the magnetic resonance imaging and stress radiographs will guide decision making. Early ACL reconstruction and acute MCL repair are recommended when there is increased medial joint space opening with valgus stress in extension, a significant meniscotibial deep MCL injury (high-riding medial meniscus), or a displaced tibial-sided superficial MCL avulsion (stener lesion of the knee). Delayed ACL reconstruction to allow for MCL healing is advised when increased valgus laxity is present only at 30 degrees of flexion and not at 0 degree. However, at the time of ACL surgery, medial stability has to be re-assessed after the reconstruction is completed. In patients with neutral alignment in the chronic setting, graft reconstruction of both the ACL and MCL is recommended.

Treatment of Partial Ulnar Collateral Ligament Tears in the Elbow With Platelet-Rich Plasma

Background: Studies have demonstrated the potential of platelet-rich plasma (PRP) to heal damaged tissue. To date, there are no published reports of clinical outcomes of partial ulnar collateral ligament (UCL) tears of the elbow treated with PRP. Hypothesis: Platelet-rich plasma will promote the healing of partial UCL tears and allow a return to play. Study Design: Case series; Level of evidence, 4. Methods: Thirty-four athletes with a partial-thickness UCL tear confirmed on magnetic resonance imaging were prospectively followed. All patients had failed at least 2 months of nonoperative treatment and an attempt to return to play. Baseline questionnaires, including the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow (KJOC) and Disabilities of the Arm, Shoulder and Hand (DASH) measures, were completed by each patient before injection. Baseline ultrasound measurement of the humeral-ulnar joint space was assessed with 10 lb of valgus stress on the elbow. Each patient received a single type 1A PRP injection at the UCL under ultrasound guidance. The same treating physician at a single institution performed all injections with the same PRP preparation used. Patients completed a course of guided physical therapy and were allowed to return to play based on their symptoms and physical examination findings. Outcome scores, including KJOC and DASH scores, were collected after return to play and were compared with baseline scores. Ultrasound measurements were collected at final follow-up and compared with preinjection values. Results: At an average follow-up of 70 weeks (range, 11-117 weeks), 30 of 34 athletes (88%) had returned to the same level of play without any complaints. The average time to return to play was 12 weeks (range, 10-15 weeks). The average KJOC score improved from 46 to 93 (P < .0001). The average DASH score improved from 21 to 1 (P < .0001). The sports module of the DASH questionnaire improved from 69 to 3 (P < .0001). Medial elbow joint space opening with valgus stress decreased from 28 to 20 mm at final follow-up (P < .0001). The difference in medial elbow joint space opening (stressed vs nonstressed) decreased from 7 to 2.5 mm at final follow-up (P < .0001). One player had persistent UCL insufficiency and underwent ligament reconstruction at 31 weeks after injection. Conclusion: The results of this study indicate that PRP is an effective option to successfully treat partial UCL tears of the elbow in athletes.

Total knee arthroplasty using anatomic alignment can produce mid-flexion laxity

BackgroundModern total knee arthroplasty offers two different alignment techniques, anatomic or mechanical, based on the bone axes selected for implantation of the prosthetic components. This study examined the axes of both during simulated physiologic knee joint motion, as well as the relationship between these axes and the implication of medial–lateral soft tissue balance in total knee arthroplasty. MethodsSeven fresh-frozen, lower limb specimens were stripped at a level 15cm from joint line, leaving the joint capsule, quadriceps muscle, hamstring tendons and ligamentous structures intact. Specimens were anatomically marked to track precise movements of the tibia and femur — from which both alignment axes were determined. Medial and lateral joint spacings were tracked to determine collateral ligament laxity. A kneeling simulator jig produced physiologic knee motion. FindingsMeasurements of medial and lateral joint spacings revealed statistically significant differences at all flexion angles between the two alignment axes. The anatomic alignment axes' pattern demonstrates mid-flexion lateral opening and late-flexion medial joint space opening — mechanical axes revealing a consistent 2–3mm larger lateral than medial joint space. InterpretationIn an effort to produce a more natural feeling knee replacement, understanding the normal kinematic soft tissue balance can serve as a useful reference point, and mid flexion laxity is an important clinical concern. With currently available total knee arthroplasty designs, mechanical alignment is preferable to anatomic alignment because it creates consistent spacing, which can be addressed by ligament lengthening or adjustments in femoral component positioning.

No difference between tibia-first and femur-first techniques in TKA using computer-assisted surgery

The measured resection technique and the gap-balancing technique are two philosophies used in total knee surgery. It is still unknown whether one or the other technique provides superior results when computer-assisted surgery is performed. We hypothesized that the gap-balancing technique improves joint stability because the technique relies primarily on the soft tissue. A prospective controlled study was performed in 116 patients using the tibia-first or femur-first technique. The Columbus(TM) total knee system and the Orthopilot(®) (Aesculap(®) AG, Tuttlingen, Germany) navigation system were used in all cases. Sixty-three patients were allocated to the femur-first technique (group F) and 53 patients to the tibial first technique (group T). The mean follow-up time was 11.4 ± 1.1 months. The KSS, KOOS and SF-36 were taken prior to surgery and at the time of follow-up for clinical assessment. Long-leg weight-bearing radiographs were performed to assess ligament alignment. Radiographs in varus and valgus stress were performed using the Telos(®)-Instrument (Telos(®) GmbH, Greisheim, Germany) under a force of 15 N at the time of follow-up for the assessment of medial-lateral stability. The nonparametric t test (Mann-Whitney U-test) was used in order to compare the ligament stability and the scores between group F and group T. The lateral joint space opening for groups F and T was 3.4° ± 1.4° and 3.9° ± 1.7°, respectively (n.s.), and the medial joint space opening for groups F and T was 4° ± 1.4° and 4.1° ± 1.7°, respectively (n.s.). The femorotibial mechanical axis for groups F and T revealed 1.4° ± 1.2° and 0.7° ± 2.0° of varus, respectively (p = 0.138). The clinical assessment showed significant improvement according to KSS, KOOS and SF-36 in all subscales. Neither of the sores showed significant differences between the two groups. The surgeon should use his/her preferred surgical technique providing the implantation is performed with computer assistance. It remains unclear whether the same findings will occur after conventional surgery. II.

What Strains the Anterior Cruciate Ligament During a Pivot Landing?

Background: The relative contributions of an axial tibial torque and frontal plane moment to anterior cruciate ligament (ACL) strain during pivot landings are unknown. Hypothesis: The peak normalized relative strain in the anteromedial (AM) bundle of the ACL is affected by the direction of the axial tibial torque but not by the direction of the frontal plane moment applied concurrently during a simulated jump landing. Study Design: Controlled and descriptive laboratory studies. Methods: Fifteen adult male knees with pretensioned knee muscle-tendon unit forces were loaded under a simulated pivot landing test. Compression, flexion moment, internal or external tibial torque, and knee varus or valgus moment were simultaneously applied to the distal tibia while recording the 3D knee loads and tibiofemoral kinematics. The AM-ACL relative strain was measured using a 3-mm differential variable reluctance transducer. The results were analyzed using nonparametric Wilcoxon signed–rank tests. A 3D dynamic biomechanical knee model was developed using ADAMS and validated to help interpret the experimental results. Results: The mean (SD) peak AM-ACL relative strain was 192% greater (P < .001) under the internal tibial torque combined with a knee varus or valgus moment (7.0% [3.9%] and 7.0% [4.1%], respectively) than under external tibial torque with the same moments (2.4% [2.5%] and 2.4% [3.2%], respectively). The knee valgus moment augmented the AM-ACL strain due to the slope of the tibial plateau inducing mechanical coupling (ie, internal tibial rotation and knee valgus moment); this augmentation occurred before medial knee joint space opening. Conclusion: An internal tibial torque combined with a knee valgus moment is the worst-case ACL loading condition. However, it is the internal tibial torque that primarily causes large ACL strain. Clinical Relevance: Limiting the maximum coefficient of friction between the shoe and playing surface should limit the peak internal tibial torque that can be applied to the knee during jump landings, thereby reducing peak ACL strain and the risk for noncontact injury.

Feasibility study of simultaneous physical examination and dynamic MR imaging of medial collateral ligament knee injuries in a 1.5-T large-bore magnet

To determine the feasibility of evaluating medial knee joint laxity with dynamic magnetic resonance (MR) imaging and simultaneous physical joint examination in a large-bore 1.5-T system. The study included 10 patients (5 women, 5 men; mean age 35years) with clinically diagnosed and categorized acute injuries of the medial collateral ligament (MCL). Intermittent valgus stress was applied separately to both the affected and the contralateral knee joint during dynamic MR imaging with a two-dimensional fast low-angle shot sequence. The width of the medial joint space and the opening angle between the femoral condyles and the tibial plateau were measured. Results obtained from dynamic MR imaging of the affected knee were compared with morphological MCL changes on static MRI, to kinematics of the contralateral side and to the clinical grading of MCL injuries. On clinical examination, all patients had grade 2 MCL injuries except one, who had a grade 1 lesion. Using morphological MRI criteria, 9 grade II and 1 grade III injuries were seen. Mean medial joint space width and opening angles of all affected knees were 2.8mm and 2.7° respectively, compared with 1.7mm and 2.1° on the contralateral side. The Wilcoxon signed rank test indicated that the differences in width (P = 0.005) and opening angle (P = 0.037) between the affected and contralateral knees were significant. Dynamic MR imaging and simultaneous physical joint examination is feasible. Our results suggest that this technique might enable the imaging documentation of medial ligamentous knee instability.

Measurement and comparison of the difference in normal medial and lateral knee joint opening

This paper reports the amount of medial and lateral knee joint opening in the general population. Knee joint lateral and medial opening at 20 degrees knee flexion was quantified on manual varus and valgus stress test, respectively, with custom made device. One hundred men and women between the ages of 20-60 years were evaluated for their joint openings. Patients with previous knee surgeries or chronic knee pains were excluded from the study. Measurements were done twice by two different orthopedic surgeons who were blinded from each other. The mean age of the study group was 39 years (range 20-60 years) and 43 years for women (range 20-60 years) and 34 years for men (range 20-60). The mean lateral and medial knee joint space opening was 7.0 degrees (range 3-9 degrees ) and 4.1 degrees (range 2-7 degrees ), respectively, in the overall population; in the male population, it was 6.7 degrees (range 3-9 degrees ) and 3.9 degrees (range 2-7 degrees ), respectively, and in the female population, it was 7.2 degrees (range 3-9 degrees ) and 4.3 degrees (range 3-7 degrees ), respectively. Conversion to displacement in millimetres, the overall mean lateral and medial joint displacement was 9.3 mm (range 5.1-13.6 mm) and 4.8 mm (range 3.5-10.7 mm), respectively; for males, it was 9.1 (range 5.1-11.9 mm) and 4.6 mm (range 3.5-7.9 mm), respectively, for females, it was 9.8 mm (range 7.2-13.6 mm) and 4.9 mm (range 3.7-10.7 mm), respectively. The prevalence of the overall population that exceeds 6 mm or more lateral joint space opening was 91% (male 90% and female 92%) and medial joint space was 8% (male 4% and female 12%). Statistically, significant differences were seen between medial and lateral opening in male, female and the overall population (p<0.001). The female population exhibited wider opening in both medial and lateral joint opening than the male population (p<0.05). The interexaminer reliability showed no significant difference (p>0.05). More than 91% of the Korean population showed wide lateral joint space opening in the bilateral knee. However, none complained of functional instability or symptoms except for non-pathologic laxity detected by the physician. We strongly recommend bilateral comparison of the knee that has wide lateral joint opening.

Hyperextension trauma to the elbow: radiological and ultrasonographic evaluation in handball goalkeepers

Objective: To detect elbow lesions produced by hyperextension in 30 elite handball goalkeepers. Methods: Conventional radiographs, stress radiographs, and ultrasound examination of both elbows were used. As a control group,...