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Due to lateral ligament laxity, bearing dislocation occurs in 1%–6% of Oxford Domed Lateral replacements. Most dislocations are medial but they do rarely occur anteriorly or posteriorly. The aim was to decrease the risk of dislocation. For a bearing to dislocate the femoral component has to be distracted from the tibial component. A robotic-path-planning-algorithm was used with a computer model of the implant in different configurations to determine the Vertical Distraction needed for Dislocation (VDD). With current components, VDD anteriorly/posteriorly was 5.5 to 6.5 mm and medially was 3.5 to 5.75 mm. A thicker bearing increased VDD medially and decreased VDD anteriorly/posteriorly (0.1 mm/1 mm thickness increase). VDD medially increased with the bearing closer to the tibial wall (0.5 mm/1 mm closer), or by increasing the tibial wall height (1 mm/1 mm height increase). VDD anteriorly/posteriorly was not influenced by bearing position or wall height. To prevent collision between the femoral and tibial components an increase in wall height must be accompanied by a similar increase in minimum bearing thickness. Increasing the wall height and minimum bearing thickness by 2 mm and ensuring the bearing is 4 mm or less from the wall increased the minimum VDD medially to 5.5 mm. The lower VDD medially than anteriorly/posteriorly explains why medial dislocation is more common. If the wall height is increased by 2 mm, the minimum bearing thickness is 5 mm and the surgeon ensured the bearing is 4 mm or less from the wall, the medial dislocation rate should be similar to the anterior/posterior dislocation rate, which should be acceptable.

Background: Medial elbow injury is common in baseball pitchers, with evidence of elbow valgus instability after only 60 consecutive pitches. However, the tissue-specific effects of repetitive pitching on medial elbow stabilizers are largely unknown. Purpose/Hypothesis: This study aimed to investigate changes in the ulnar collateral ligament (UCL) and forearm flexor-pronator muscles (FPMs) during repetitive pitching and factors that relate to identified change. We hypothesized that repetitive pitching would increase elasticity of the medial elbow stabilizers and therefore induce laxity. Study Design: Descriptive laboratory study. Methods: A total of 30 high school baseball pitchers participated (mean ± SD age, 16.6 ± 0.5 years). Each participant pitched 100 times (5 blocks of 20 pitches). The strain ratio, indicating elasticity in the UCL and FPMs, was measured using ultrasound before pitching and after every 20-pitch block. Data for each pitch block were compared using analysis of variance. Multiple regression analysis was used to investigate factors related to the change rate of the strain ratio. Results: The strain ratio of the UCL after 100 pitches was significantly less than that before pitching (before pitching, 4.83 ± 1.70; after 100 pitches, 3.59 ± 1.35; P = .013), but this was not the case for the FPMs (before pitching, 0.57 ± 0.24; after 100 pitches, 0.43 ± 0.18; P = .07). The ratio of the strain ratio in the UCL and FPMs (UCL/FPMs) before pitching (β = −0.385; P = .031) and the elbow flexion range of motion before pitching (β = −0.352; P = .046) were significantly and independently correlated with the change rate of the UCL. Conclusion: Elasticity significantly increased for the UCL, indicating laxity, but not for the FPMs after 100 pitches. Furthermore, the ratio of elasticity (UCL/FPMs) and the elbow flexion range of motion before pitching were significantly related to the change rate of UCL elasticity. Clinical Relevance: To reduce laxity of the UCL, pitchers should be limited to

Haptic robotic-arm-assisted total knee arthroplasty (RATKA) seeks to leverage three-dimensional planning, intraoperative assessment of ligament laxity, and guided bone preparation to establish and achieve patient-specific targets for implant position. We sought to compare (1) operative details, (2) knee alignment, (3) recovery of knee function, and (4) complications during adoption of this technique to our experience with manual TKA. We compared 120 RATKAs performed between December 2016 and July 2018 to 120 consecutive manual TKAs performed between May 2015 and January 2017. Operative details, lengths of stay (LOS), and discharge dispositions were collected. Tibiofemoral angles, Knee Society Scores (KSS), and ranges of motion were assessed until 3 months postoperatively. Manipulations under anesthesia, complications, and reoperations were tabulated. Mean operative times were 22 minutes longer in RATKA (p

International audience; OBJECTIVE:Pregnancy-related changes in ligament laxity have been shown to be associated with various disorders such as back pain or pelvic floor disorders. The purpose of this study was to assess laxity changes during pregnancy by confronting different methods in order to suggest a simple clinical tool helping to prevent the aforementioned problems.DESIGN:Seventeen pregnant women were evaluated at the first, second and third trimesters as cases and 16 non-pregnant women participated as controls. Ligamentous laxity was measured using an extensometer for the metacarpophalangeal joint of the index, a fingertip to floor test and a sit and reach test to assess hip and lumbar flexibility and the Beighton score. Statistical analysis included independent samples t-tests, analysis of variance and Pearson correlation coefficients.RESULTS:Laxity of the metacarpophalangeal joint increased by 11% from the first to the second trimester of pregnancy and stabilized until delivery. The Beighton score was significantly higher in the second trimester of pregnancy (p

Pure ankle dislocation is a rare event that primarily results from high-energy trauma. Predisposing anatomical factors such as talar hypoplasia, ligament laxity, and previous sprains may play a key role. This report presents the case of a 55-year-old man with fatal anterior and posterior tibial artery tears following a pure anterolateral dislocation of the right ankle. To the best of our knowledge, no such cases have previously been reported in the English-language literature.

The pathogenesis of Adolescent Idiopathic Scoliosis (AIS) remains unclear. Previous research proposed that ligament laxity is a clinical feature that can be easily overlooked in patients with AIS. We speculated a new hypothesis which is an improvement of our three-dimensional spring model hypothesis of AIS pathogenesis. The tethered string in the spring model stimulates the spinal ligament instead of spinal cord. Spinal overgrowth in the adolescent age leads to higher tension of posterior spinal ligament. And the ligament laxity leads to lower tension of anterior spinal ligament. This uncoupled anterior and posterior spinal ligament tension maybe the key cause of AIS.

To evaluate the clinical outcome of this modified physeal-sparing technique for MPFL reconstruction in skeletally immature patients with ligament laxity. This study was conducted on 16 patients (11 females and 5 males) with an average age of 11.5 years (8–15). They all had recurrent patellar dislocation with generalized ligament laxity (mean Beighton’s score of 7) and no patellar tilt on X-ray. We modified the Frank Noyes’ non-anatomic technique for MPFL reconstruction to become anatomic without hardware fixation for the graft. The mean follow-up period was 29.25 months (SD 4.3) ranged from 24 to 34 months. Preoperative Kujala score had ranged from 49 to 61 points (mean of 56, SD 4.72), improved to be ranged from 90 to 99 points (mean 94, SD 2.73), which is considered highly significant (p value

Background Context Predicting physiological range of motion (ROM) using a finite element (FE) model of the upper cervical spine requires the incorporation of ligament laxity. The effect of ligament laxity can be observed only on a macro level of joint motion and is lost once ligaments have been dissected and preconditioned for experimental testing. As a result, although ligament laxity values are recognized to exist, specific values are not directly available in the literature for use in FE models. Purpose The purpose of the current study is to propose an optimization process that can be used to determine a set of ligament laxity values for upper cervical spine FE models. Furthermore, an FE model that includes ligament laxity is applied, and the resulting ROM values are compared with experimental data for physiological ROM, as well as experimental data for the increase in ROM when a Type II odontoid fracture is introduced. Design/Setting The upper cervical spine FE model was adapted from a 50th percentile male full-body model developed with the Global Human Body Models Consortium (GHBMC). FE modeling was performed in LS-DYNA and LS-OPT (Livermore Software Technology Group) was used for ligament laxity optimization. Methods Ordinate-based curve matching was used to minimize the mean squared error (MSE) between computed load-rotation curves and experimental load-rotation curves under flexion, extension, and axial rotation with pure moment loads from 0 to 3.5 Nm. Lateral bending was excluded from the optimization because the upper cervical spine was considered to be primarily responsible for flexion, extension, and axial rotation. Based on recommendations from the literature, four varying inputs representing laxity in select ligaments were optimized to minimize the MSE. Funding was provided by the Natural Sciences and Engineering Research Council of Canada as well as GHMBC. The present study was funded by the Natural Sciences and Engineering Research Council of Canada to support the work of one graduate student. There are no conflicts of interest to be reported. Results The MSE was reduced to 0.28 in the FE model with optimized ligament laxity compared with an MSE 0f 4.16 in the FE model without laxity. In all load cases, incorporating ligament laxity improved the agreement between the ROM of the FE model and the ROM of the experimental data. The ROM for axial rotation and extension was within one standard deviation of the experimental data. The ROM for flexion and lateral bending was outside one standard deviation of the experimental data, but a compromise was required to use one set of ligament laxity values to achieve a best fit to all load cases. Atlanto-occipital motion was compared as a ratio to overall ROM, and only in extension did the inclusion of ligament laxity not improve the agreement. After a Type II odontoid fracture was incorporated into the model, the increase in ROM was consistent with experimental data from the literature. Conclusions The optimization approach used in this study provided values for ligament laxities that, when incorporated into the FE model, generally improved the ROM response when compared with experimental data. Successfully modeling a Type II odontoid fracture showcased the robustness of the FE model, which can now be used in future biomechanics studies.

Background: The contribution of mechanical laxity and ligament stiffness to chronic ankle instability is unclear, particularly when using the inversion laxity test, and may have implications for diagnosis, prognosis, and treatment. Our purpose was to determine if individuals with chronic ankle instability demonstrate greater mechanical ligament laxity and altered stiffness compared to controls and copers (those with a healed sprain) during an instrumented arthrometer inversion stress test. Methods: Recreationally active individuals were classified as those with chronic ankle instability (n = 16), copers (n = 16), or controls (n = 16) based on injury history and self-reported score on the Cumberland Ankle Instability Tool (CAIT). Three trials of an inversion stress test were applied with an instrumented arthrometer utilizing a reliable tester. Talocrural inversion (degrees) and stiffness values were extracted. One-way ANOVAs were calculated, and Tukey post hoc testing was applied (α ≤ .05). Results: Groups were not different in age, height, or weight. The chronic ankle instability group (19 ± 6) had significantly lower CAIT scores than the control (30 ± 1) and coper (29 ± 1) groups ( P < .001). The chronic ankle instability group (23 ± 12 degrees) demonstrated significantly greater inversion than the controls (13 ± 9 degrees) ( P = .04) but was not significantly different than the copers (17 ± 10 degrees). No significant differences were detected in stiffness between the groups. Conclusion: The chronic ankle instability group demonstrated decreased self-reported ankle function and increased mechanical laxity utilizing an instrumented arthrometer for inversion compared to the control group but not the coper group. Laxity, but not stiffness, may be a factor affecting chronic ankle instability and self-reported function. Level of Evidence: Level III, comparative study.

We report the case of an 18-years-old patient with thumb carpometacarpal ligament laxity due to Ehlers-Danlos syndrome who was treated with trapezial opening wedge osteotomy combined with volar ligaments reconstruction. Two years postoperatively she is pain free and the thumb carpometacarpal joint is stable.

These authors describe an orthosis they have successfully used in their clinic to treat patients with distal radioulnar joint instability. In addition to describing how they fabricate the orthosis, these authors also describe how they determine if the patient needs volar or dorsal support, and how they then incorporate this support into the orthosis - Victoria Priganc, PhD, OTR, CHT, CLT, Practice Forum Editor.

A 37-year-old woman was diagnosed with an isolated proximal tibiofibular joint dislocation (PTJD) after an accident during gymnastic exercise. The dislocation has a low incidence rate and is often missed in the emergency department as physical and radiology signs are subtle. Treatment consists of closed or open reduction and immobilisation. When it is not recognised it is associated with significant peroneal nerve injury.

The dynamic anterior ankle tester (DAAT) has shown a good reliability in testing anterior talar translation in earlier studies. The goal of the present study was first to evaluate the reliability of the DAAT in a clinical setting and second to analyze its ability to detect increased ligament laxity. In 39 patients with unilateral chronic lateral ankle instability, the anterior talar translation of the affected and non-affected side was measured pre and postoperatively using the DAAT, Telos stress radiographs, and the manual anterior drawer test. In contrast to both other tests, the DAAT was not able to accurately detect increased ligament laxity preoperatively or decreased laxity of the affected ankle postoperatively. The DAAT showed a low sensitivity to change (the difference between the mean pre and postoperative value) and a low reliability compared to both other tests. There were no correlations between the three tests. In conclusion, the DAAT showed a low reliability in effectively testing lateral ankle ligament laxity in a clinical setting. This is in contrast to earlier evaluations.

Exercise is an important component of a healthy lifestyle and, as such, is recommended during pregnancy. However, the response to exercise of both the expectant mother and fetus varies depending on the fitness level of the woman. The response to exercise is also affected by the known musculoskeletal and physiologic changes associated with pregnancy, such as increased ligament laxity, weight gain, change in the center of gravity, and carpal tunnel syndrome. Although the physiologic responses of the pregnant woman and fetus have been well studied, the literature contains comparatively few studies investigating response to exercise. When performed properly, activities such as aerobics, impact and nonimpact activities, resistance training, and swimming may be beneficial during pregnancy.

Injuries to the collateral ligaments of the knee are very common. Recognition of collateral ligament laxity is extremely important, especially when associated with a cruciate ligament injury. Reconstruction of the collaterals are necessary when addressing these combined instabilities.

Background: Not all patients develop chronic ankle instability (CAI) after one or more lateral ankle sprains; some seem to heal or adjust to the ankle laxity after injury. Why do some patients develop CAI and others are able to cope and return to normal function? The purpose of this study was to examine ligament laxity between subjects with and without CAI. Materials and Methods: Sixteen subjects with unilateral CAI and 16 subjects without participated in the study. Ligament laxity was measured with an instrumented ankle arthrometer. The arthrometer measured ankle joint motion for anterior/posterior displacement (mm) during loading at 125 N and inversion/eversion rotation (degrees of ROM) during loading at 4000 N/mm. For each dependent variable a 2 × 2 mixed model ANOVA was run with the between factor being group (CAI, No CAI) and the within factor with repeated measures being side (involved, uninvolved). Results: A significant group by side interaction for anterior displacement (F1,30 = 370.085, p < 0.001), and inversion rotation (F1,30 = 7.455, p = 0.010) was found. There was significantly more anterior displacement and inversion rotation for the involved ankles of the CAI group than the involved ankles of the stable group and the uninvolved ankles of the CAI group. Conclusion: Based on the results of this study it appears that the increased anterior displacement and inversion rotation compared to patients without instability may be why subjects develop CAI. Although the patients without instability have a history of more than one lateral ankle sprain, they did not demonstrate increased laxity, which may be the reason why they do not complain of the functional impairment demonstrated in subjects with CAI.

Mechanical alignment has been overlooked as an important contributor to knee stability with respect to collateral ligament laxity. The detrimental effects of varus or valgus limb malalignment become more obvious when the restraining force is lost because of ligamentous injury especially on the medial or the lateral/posterolateral side. Even with repair or reconstruction of these injuries, with repetitive load, the ligament will eventually fail to restore its structure and strength, resulting in failure and secondary restraint laxity. We have found that realignment of the limb is the most important factor in restoring a functional limb. After realignment, joint laxity, if persistent, can be addressed successfully with ligamentous reconstruction. Diagnosis and treatment of limb malalignment cannot be ignored in the management of chronic ligamentous instabilities, especially those with prior failed reconstruction. Our approach to these difficult problems and the preferred techniques of osteotomies on both tibial and femoral sides are described.

BACKGROUND: Fear of iatrogenic growth disturbance has prevented the routine use, in children, of anatomic methods of anterior cruciate ligament replacement that have proven successful in adults. To minimize the risk of growth disturbance, extra-articular or modified physeal sparing procedures have been performed to stabilize the knee, but these procedures do not provide isometry. This study was performed to evaluate the results of a transepiphyseal replacement of the anterior cruciate ligament in skeletally immature athletes. METHODS: From 1993 to 1999, twelve patients with a mean age (and standard deviation) of 13.3 ± 1.4 years underwent replacement of the anterior cruciate ligament with a quadruple hamstring tendon graft performed with an arthroscopic technique and intraoperative fluoroscopic imaging for precise tunnel placement. The femoral and tibial tunnels went through the epiphyses but avoided the physes. Eight of the twelve patients also had a meniscal repair. All patients returned for follow-up, at a mean of 4.1 ± 1.9 years (range, two to 8.2 years) after surgery. RESULTS: The mean amount of growth from the time of surgery to the time of follow-up was 16.5 ± 10.0 cm (range, 8 to 38 cm). The difference between the lengths of the lower limbs, as measured on orthoradiographs, was not clinically relevant. The mean score on the International Knee Documentation Committee (IKDC) subjective knee form was 96.5 ± 4.4 points (range, 86 to 100 points). Ligament laxity testing with a KT-1000 arthrometer revealed a mean side-to-side difference of 1.5 ± 1.1 mm. The rating according to the criteria of the objective 2001 IKDC knee form was normal for seven patients and nearly normal for five. CONCLUSIONS: Transepiphyseal replacement of the anterior cruciate ligament, a technically demanding procedure with a small margin of error, should be attempted only by accomplished knee surgeons. The preliminary results in this small series, however, demonstrate that this surgical technique can be performed in prepubescent patients with efficacy and relative safety.

Proper alignment and balancing of soft tissues of the knee are important goals for TKA. Despite standardized techniques, there is no consensus regarding the optimum amount of collateral ligament laxity one should leave at the end of the TKA.I asked (1) what is the collateral laxity in young healthy volunteers, and (2) is there a difference in collateral laxity between males and females.The femorotibial mechanical angle (FTMA) was measured in 314 knees in healthy volunteers aged 19 to 35 years. Subjects with a history of pain, malalignment, dysplasia, or trauma were excluded. Twenty-five knees were excluded because the hip center could not be acquired, and 22 were excluded because of a history of pain and trauma, leaving 267 knees for inclusion in the study. Of these, 155 were from men and 112 were from women. A validated method using a computer navigation system was used to obtain the measurements. A 10-Nm torque was used to stress the knee in varus and valgus at 0° extension and 15° flexion. An independent t-test and ANOVA were applied to the data to calculate any significant difference between groups (p0.05).The mean (SD) unstressed supine FTMA was varus of 1.2° (SD, 4°) in 0° extension and varus of 1.2° (SD, 4.4°) in 15° flexion (p=0.88). On varus torque of 10 Nm, the supine FTMA changed by a mean of 3.1° (SD, 2°) (95% CI, 2.4°-3.8°; p0.001) in 0° extension and 6.9° (SD, 2.6°) (95% CI, 6.2°-7.7°; p0.001) in 15° flexion. On valgus torque of 10 Nm, the FTMA changed by a mean of 4.6° (SD, 2.2°) (95% CI, 3.9°-5.3°; p0.001) in 0° extension and 7.9° (SD, 3.4°) (95% CI, 7.1°-8.7°; p0.001) in 15° flexion. The mean unstressed FTMA in 0° extension was varus of 1.7° (SD, 4°) in men and 0.4° (SD, 3.9°) in women (p=0.01). Differences in collateral ligament laxity were seen between men and women (p0.001 for valgus torque and 0.035 for varus torque in 15° flexion). With valgus torque at 0° flexion, the supine FTMA change was valgus of 4.2° (SD, 2.0°) for men and 5.0° (SD, 2.4°) for women, while at 15° flexion the FTMA change was valgus 7.6° (SD, 3.6°) for men and 8.3° (SD, 3.2°) for women With varus torque at 0° flexion, additional varus was -3.0° (SD, 1.8°) for men and -3.3° (SD, 2.2°) for women, while at 15° flexion, varus was -7.0° SD, (2.5°) for men and -6.9° (SD, 2.8°) for women.The collateral laxity in young healthy volunteers was quantified in this study. The collateral ligament laxity is variable in different persons. In addition, ligaments in women are more lax than in men in valgus stress.This study was conducted on young, healthy knees. Whether the findings are applicable to arthritic knees and replaced knees needs additional evaluation. However the findings provide a baseline from which to work in the evaluation of arthritic knees and in the case of TKA.

The aim of this study was to evaluate laxity in knees with pre-operative (preop) valgus alignment compared to knees with pre-operative varus alignment after total knee arthroplasty (TKA).This was a retrospective study including 81 patients, with six years follow-up, for pre-operative valgus- or varus alignment of the leg. All patients had been supplied with the same cruciate retaining (CR) TKA with rotating platform. Clinical findings were assessed by KSS, OKS and IKDC 2000 score. Rotational knee laxity was evaluated by a validated instrument (Laxitester®) with 2 Nm torque in 30° flexion. Collateral ligament laxity was tested manually in 30° flexion with a bending moment of approximately 5 Nm. Biomechanical results were compared to the contralateral side.Thirty-one patients had a preop valgus alignment of 8.96° and 50 patients a varus leg axis of 4.99° in the mean. In the preop valgus knees rotational analysis showed an increased laxity of 10.7° compared to preop varus knees (p = 0.001). There was no significant difference in medial (valgus 2.6 mm, varus 2.5 mm) and lateral (valgus 2.8 mm, varus 2.7 mm) laxity. KSS and OKS showed no significant differences in the follow-up results. In the IKDC 2000 objective score 50 % of the preop varus knees and 25.8 % of the preop valgus knees were classified as nearly normal. The difference in the IKDC objective was highly significant (p0.001).Preop valgus knees show a significantly increased rotational laxity but no increased collateral ligament laxity compared to pre-operative varus knees six years after TKA with rotating platform. There is a significant difference in IKDC objective.

Purpose To assess the normal degree of laxity of the collateral ligaments (CLs) of the finger metacarpophalangeal (MCP) joints and to compare side-to-side differences in CL laxity. Methods One hundred subjects had measurements of the degree of laxity in the radial (RCL) and ulnar (UCL) collateral ligaments of the MCP joints of each digit on both hands with the joints at neutral and at 30° and 90° of flexion using a custom-made measuring device. Statistical analysis was performed to assess both the difference in laxity for each ligament at each position of flexion and between sides for analogous ligaments (eg, the right index RCL at neutral compared to the left index RCL at neutral). Results There was a significant decrease in laxity for all ligaments between neutral (mean, 24° laxity) and 90° of flexion (mean, 15° laxity). There was a side-to-side difference between the RCL of all digits in extension (mean, 3°) and the index RCL in flexion (2°). These differences were statistically significant but clinically minimal. There were no side-to-side differences between any of the other ligaments at any position. Conclusions Finger MCP joint CL stability increases with increasing flexion of the joint. There is little to no difference between analogous ligaments on either hand of the subject when tested in the same position of MCP joint flexion. Knowledge of the average degree of MCP joint CL laxity can be helpful in assessing a potentially injured joint. A patient's contralateral, uninjured side can be used to determine that individual's normal laxity and a substantial increase from this on an injured digit can indicate CL rupture. Type of study/level of evidence Diagnostic II.

Purpose To find out if there is an association between ligament laxity measured intraoperatively and functional outcome 1 year after total knee arthroplasty (TKA). Methods Medial and lateral ligament laxities were measured intraoperatively in extension and in 90° of flexion in 108 patients [122 knees; median age 70 (range 42–83) years]. Mechanical axes were measured preoperatively and at 1-year follow-up. Outcome measures were the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Knee Society Clinical Rating System, the Oxford Knee Score and patient satisfaction. The relationships between laxity and outcome scores were examined by median regression analyses. Results Post-operative mechanical axis had a significant effect on the association between ligament laxity and KOOS. Therefore, the material was stratified on post-operative mechanical axis. In perfectly aligned and valgus-aligned TKAs, there was a negative correlation between medial laxity and all subscores in KOOS. The most important regression coefficient (β) was recorded for the effect of medial laxity in extension on activities of daily living (ADLs) (β = −7.32, p

OBJECTIVE:: Ankle sprains are the most common injury in the active population. With high reinjury rates and complaints of the ankle "giving way," it has been suggested that laxity of ankle ligaments increases with repeated sprains. The objective of this study was to determine if a relationship exists between ligament laxity and the number of ankle sprains. DESIGN:: Cross-sectional study. SETTING:: Biomechanics laboratory. PARTICIPANTS:: A total of 203 Division I collegiate athletes (84 women; 119 men; age, 18.5 ± 1.1 years; height, 178.5 ± 10.8 cm; mass, 79.8 ± 18.7 kg) participated in the study. INTERVENTION:: Each participant reported the number of previous sprains on each ankle. Ligament laxity was measured using an instrumented ankle arthrometer. MAIN OUTCOME MEASURES:: Measurements for anterior displacement (AD), inversion (IV), and eversion (EV) rotation of the ankle were obtained using an instrumented ankle arthrometer. RESULTS:: There was no relationship between ligament laxity and the number of ankle sprains in either direction (AD, P = 0.86; IV, P = 0.64; EV, P = 0.81). In addition, comparing ligament laxity between previously sprained ankles and ankles that have never been sprained resulted in no differences in the direction of movement (AD, P = 0.98; IV, P = 0.96; EV, P = 0.67). CONCLUSIONS:: Despite anecdotal evidence suggesting repeated ankle sprains increase ligament laxity, this report involving a large data set and a reliable measurement analysis found no relationship between the two. The results of this study make it necessary to rethink the causes of ligament laxity. Therefore, further research is necessary to understand the causes of "giving way" of the ankle and their role in repeated ankle sprains. Language: en

We prospectively enrolled 160 consecutive patients with inversion trauma of the ankle in a diagnostic protocol that included physical examination within 2 days and at 5 days after trauma, arthrography, stress radiography, and ultrasonography. 135 patients had pathological lateral ligament laxity on the later physical examination or lateral ligament rupture diagnosed on arthrography and they were operated on 122 of these patients had ligament ruptures. At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures. Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information.

Anterior tibial tunnel placement contributed to the failure of two previous anterior cruciate ligament reconstructions. An allograft patellar bone-tendon-bone nonunion within the tibial tunnel caused dysfunctional ligament laxity. This is the first report of this type of reconstructive cruciate ligament failure.

Correct ligamentous balancing is an important determinant of the clinical outcome in total knee arthroplasty (TKA). Many surgeons prefer a tight rather than a lax knee during implantation of a TKA. The hypothesis in this study was that patients with a slightly laxer knee joint might perform better than patients with a tight knee joint after implantation of a TKA.Twenty-two patients with bilateral knee arthroplasties were clinically and radiologically evaluated at a mean follow-up of 4.5 years, ranging from 2 to 7 years. There were 12 women and 10 men with an average age of 68.9 years (range 32-82 years) at the time of surgery. A modified HSS score (excluding laxity), varus and valgus stress X-rays in 30 degrees of knee flexion, and the subjective outcome of both knees were compared. A knee was considered tight when it opened less than 4 degrees and lax if it opened 4 degrees or more on stress X-ray.There was a trend towards improved range of motion and HSS score for the laxer knee joints. However, the difference did not achieve statistical significance. Eleven of the 22 patients considered one side subjectively better than the other side. In 10 out of these 11 TKA, the slacker knee joint was the preferred side ( p0.05).As the present study compared bilateral knee joints after TKA, the same patient could act as a control group, and subtle subjective differences were revealed which are not quantifiable. The results showed that patients with a preferred side felt significantly more comfortable on the laxer side, indicating that during intraoperative ligamentous tensioning, some varus and valgus laxity at 20-30 degrees of flexion might be preferable to an over-tight knee joint. Further biomechanical and prospective investigations will be necessary to establish the correct soft-tissue tensioning.

Heat has been used as a therapeutic form of treatment in the field of medicine since ancient times. Electrothermal energy delivered by radiofrequency has the advantages of being able to be used by even the casual arthroscopist and being relatively inexpensive. One of the expanded uses is treating ligament laxity, including the anterior cruciate.

Background: It is now generally accepted that the ligamentous structures of the knee not only act as mechanical restraints but also have a neurophysiological role in joint function and protection. A report that knee joint laxity increases with exercise raised the question as to whether there is any compensatory change in joint position appreciation. Objective: To test whether there is a compensatory mechanism for increased ligamentous laxity during normal levels of activity. Methods: Joint position appreciation was measured, using a previously reported technique, in the knees of sportsmen at rest and after warm up. Results: Joint position appreciation was found to be significantly more sensitive after warm up (p = 0.005). Conclusions: These findings indicate that joint position appreciation within the knee accommodates physiological changes within the ligaments and muscles after exercise.

We implanted the total arthroplasty knee or TACK prosthesis in 40 patients with degenerative osteoarthritis. We used the same surgical technique in all patients. Full extension and flexion more than 90 degrees were achieved in all 40 knees. All patients obtained a HSS score of more than 88 points. The results confirm that the TACK prosthesis provides excellent results in patients with degenerative osteoarthritis if there is no significant bone loss, serious ligament laxity or extensive deformation.

Collateral ligament laxity has recently been recognized as an important component of frontal plane malalignment. The authors have developed new surgical techniques to re-tension lax collateral ligaments. Twenty-three collateral ligament re-tensioning with bony alignment were carried out in 17 patients, with 19 knees being graded excellent, 2 fair, and 2 poor. Recurrence of significant laxity was noted in one patient.

We analysed static footprints of 2300 children between the ages of four and 13 years to establish the influence of footwear on the prevalence of flat foot. The incidence among children who used footwear was 8.6% compared with 2.8% in those who did not (p less than 0.001). Significant differences between the predominance in shod and unshod children were noted in all age groups, most marked in those with generalised ligament laxity. Flat foot was most common in children who wore closed-toe shoes, less common in those who wore sandals or slippers, and least in the unshod. Our findings suggest that shoe-wearing in early childhood is detrimental to the development of a normal longitudinal arch.

A 24-year-old professional football player sustained an isolated rupture of the popliteus tendon. The injury was confirmed by arthroscopic examination. No clinical instability was present initially or during the recovery period. The injury was managed nonoperatively with the patient able to return to full sports participation. No residual ligament laxity or weakness on isokinetic testing resulted.

Measurements have been made on knee radiographs exposed during stress displacement by controlled hydraulic forces using a specially designed apparatus. This accurately records the amount of anterior and posterior tibial displacement (drawer sign) and the degree of medial and lateral collateral ligament laxity on radiographs. The findings in 25 patients have been analysed following the Jones' procedure for the repair of the anterior cruciate ligaments. The operative results were judged to be completely successful in 72 per cent of patients and the value of stress radiographic measurements is discussed.

After review of the first 209 polycentric total knee arthroplasties (in 159 patients) performed at the Mayo Clinic between July 1970 and November 1971, we found that the calculated probability of the arthroplasty remaining successful ten years postoperatively was 66 per cent. Actual results showed 42 per cent of the arthroplasties to be successful in patients who were still alive at review; another 24 per cent were successful but were in patients who had died or were lost to follow-up before ten years postoperatively. In 34 per cent failure occurred, which we defined as reoperation for any reason, unacceptable pain, or loss of function. The most common causes of failure were instability or ligament laxity (13 per cent), loosening of a component (7 per cent), infection (3 per cent), and patellofemoral joint pain (4 per cent). Prior knee surgery significantly decreased the probability of success, as did axial malalignment of the prosthetic components at operation.

Linscheid and Dobyns (1972), in a classical article on post-traumatic instability of the wrist described two major types of instability, dorsal and volar. The dorsal intercalated segment instability (D.I.S.I.) was the more common and occurred with scapholunate dissociation and displaced scaphoid fractures. The instability occurred in these conditions as a result of the scaphoid losing its ability to support the carpus. They presented five cases of volar intercalated segment instability (V.I.S.I.) of which four were related to congenital ligament laxity and not to traumatic ligament disruption. In the one case of traumatic origin they felt that the capitolunate ligament was ruptured. However, more recent publications by Taleisnik, Prietto (1982) and Reagan, (1984) have proposed that for V.I.S.I. to occur the lunate triquetral interosseous ligament must be disrupted. We report this case as it demonstrates which ligamentous structures are torn for V.I.S.I. to occur. In addition, these ligament disruptions were pathological and occurred spontaneously as a result of longterm systemic steroid medication.

Of 45 consecutive knees undergoing Macintosh fascia lata anterior cruciate substitution, only five had accompanying collateral ligament laxity. Over a third of cases (16) had more than ten episodes of major instability causing falls to the ground pre-operatively. The initial injury caused haemarthrosis, usually without external trauma (36), was often accompanied by a sensation of knee disruption (18), and was always associated with immediate disability. The results of 26 lateral substitution operations with minimum 12 month follow-up show abolition of pivot shift jerk in all patients. Incomplete control of objective and functional instability postoperatively in four patients may have been related to soft tissue stretching associated with early mobilization in a cast-brace or generalized ligamentous laxity.

he proXimal interphalangeal (PIP) joint is par­ticularly susceptible to acute ligamentous in­jury, and such an injury can result in swelling without ligament laXity, collateral ligament laXity and disruption, or a partial or complete avulsion of the volar plate with or without bony involvement. Many articles have been written about methods for treat­ment of injuries to this joint (Bowers

1. Recurrent dislocation of the elbow is caused primarily by collateral ligament laxity with secondary damage to the capitulum and head of radius. 2. The pathological changes resemble those of recurrent dislocation of the shoulder. 3. Subluxation or instability of the radial head is often associated with capsular ossification and deserves wider recognition because it may be confused with osteochondritis dissecans. 4. A simple method of soft-tissue repair has successfully prevented redislocation of eight elbows.

A case with stress fracture of the body of the pubic bone which occurred in a 35-year-old pregnant woman is described. No underlying pathologic process was found and it would seem that the mechanical load acting on the pubic bone to cause stress fracture is brought about by both the muscle imbalance and ligament laxity. In a few weeks after delivery, the fracture showed a complete bony union.

All patients returning from skiing holidays who had sustained injuries of the knee ligaments were assessed. Thirteen patients had radiologically evident flake fractures around the knee. Of these, all had marked laxity when examined under anaesthetic. In ten cases the accident had occurred at low speed. It is concluded that all knee injuries following a skiing fall must be examined to exclude ligament laxity. The relevance of the bony flakes is discussed.

Forty-seven patients who had been treated by 63 total knee arthroplasties were assessed at 12-84 months after the operation. The data were analyzed to determine if collateral ligament laxity had a detrimental effect on the clinical outcome. The Hospital for Special Surgery (HSS) score was used to make the clinical assessment and a modified HSS score, which excluded points awarded for laxity, was also used. Unidirectional (varus or valgus) and total (varus and valgus) laxity were used as a basis of analysis. None of the examined parameters produced results suggesting that lax knees were worse than stable knees. Indeed, knees with increasing laxity through the categories of mild and moderate showed better statistically significant results in HSS score and pain than those with lesser degrees of laxity. Seventy-five percent of the knees with unidirectional laxity were classified as excellent; only 38.5% of the stable knees were graded as excellent (p less than 0.01). Only 9% of the lax knees had complaints of pain; 38% of the stable knees were painful (p less than 0.05). No significant difference in functional score and walking ability was noted between the lax and the stable knees. Seventy-eight percent of the lax knees had a range of motion over 100 degrees; 62.5% of the stable knees achieved this range.