The Cumberland ankle instability tool: a report of validity and reliability testing

OBJECTIVE

To test the Cumberland Ankle Instability Tool (CAIT), a 9-item 30-point scale, for measuring severity of functional ankle instability.

DESIGN

Cross-sectional study.

SETTING

General community.

PARTICIPANTS

Volunteer sample of 236 subjects.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Concurrent validity by comparison with the Lower Extremity Functional Scale (LEFS) and a visual analog scale (VAS) of global perception of ankle instability by using the Spearman rho. Construct validity and internal reliability with Rasch analysis using goodness-of-fit statistics for items and subjects, separation of subjects, correlation of items to the total scale, and a Cronbach alpha equivalent. Discrimination score for functional ankle instability by maximizing the Youden index and tested for sensitivity and specificity. Test-retest reliability by intraclass correlation coefficient, model 2,1 (ICC(2,1)).

RESULTS

There were significant correlations between the CAIT and LEFS (rho=.50, P<.01) and VAS (rho=.76, P<.01). Construct validity and internal reliability were acceptable (alpha=.83; point measure correlation for all items, >0.5; item reliability index, .99). The threshold CAIT score was 27.5 (Youden index, 68.1); sensitivity was 82.9% and specificity was 74.7%. Test-retest reliability was excellent (ICC(2,1)=.96).

CONCLUSIONS

CAIT is a simple, valid, and reliable tool to measure severity of functional ankle instability.

A framework for the classification of joint hypermobility and related conditions

In the last decade, growing attention has been placed on joint hypermobility and related disorders. The new nosology for Ehlers-Danlos syndrome (EDS), the best-known and probably the most common of the disorders featuring joint hypermobility, identifies more than 20 different types of EDS, and highlights the need for a single set of criteria to substitute the previous ones for the overlapping EDS hypermobility type and joint hypermobility syndrome. Joint hypermobility is a feature commonly encountered in many other disorders, both genetic and acquired, and this finding is attracting the attention of an increasing number of medical and non-medical disciplines. In this paper, the terminology of joint hypermobility and related disorders is summarized. Different types of joint hypermobility, its secondary musculoskeletal manifestations and a simplified categorization of genetic syndromes featuring joint hypermobility are presented. The concept of a spectrum of pathogenetically related manifestations of joint hypermobility intersecting the categories of pleiotropic syndromes with joint hypermobility is introduced. A group of hypermobility spectrum disorders is proposed as diagnostic labels for patients with symptomatic joint hypermobility but not corresponding to any other syndromes with joint hypermobility. © 2017 Wiley Periodicals, Inc.

Lumbar segmental 'instability': clinical presentation and specific stabilizing exercise management

Lumbar segmental instability is considered to represent a significant sub-group within the chronic low back pain population. This condition has a unique clinical presentation that displays its symptoms and movement dysfunction within the neutral zone of the motion segment. The loosening of the motion segment secondary to injury and associated dysfunction of the local muscle system renders it biomechanically vulnerable in the neutral zone. The clinical diagnosis of this chronic low back pain condition is based on the report of pain and the observation of movement dysfunction within the neutral zone and the associated finding of excessive intervertebral motion at the symptomatic level. Four different clinical patterns are described based on the directional nature of the injury and the manifestation of the patient's symptoms and motor dysfunction. A specific stabilizing exercise intervention based on a motor learning model is proposed and evidence for the efficacy of the approach provided.

Classification of glenohumeral joint instability

Shoulder instabilities have been classified according to the etiology, the direction of instability, or on combinations thereof. The current authors describe a classification system, which distinguishes between static instabilities, dynamic instabilities, and voluntary dislocation. Static instabilities are defined by the absence of classic symptoms of instability and are associated with rotator cuff or degenerative joint disease. The diagnosis is radiologic, not clinical. Dynamic instabilities are initiated by a trauma and may be associated with capsulolabral lesions, defined glenoid rim lesions, or with hyperlaxity. They may be unidirectional or multidirectional. Voluntary dislocation is classified separately because dislocations do not occur inadvertently but under voluntary control of the patient.

Improperly placed anterior cruciate ligament grafts: correlation between radiological parameters and clinical results

Despite increasing knowledge on knee biomechanics and refined operative techniques, an increasing number of patients are being seen with failed anterior cruciate ligament (ACL) reconstruction. Failure of the reconstruction and further damage to the knee are correlated with improper placement of the graft, which interferes with graft biology and biomechanical demands. Between 1994 and 1995, 63 patients with improperly placed ACL grafts were referred to our institution because of persistent knee instability and pain. A method for analysis of the femoral drill hole on radiography was developed. Before reoperation the radiograph was evaluated by our method, noting the clinical aspects according to the recommendations of the International Knee Documentation Committee (IKDC). The femoral placement of the ACL graft could easily be defined on the lateral and anteroposterior tunnel radiography. The most common error was a femoral placement anterior to the anatomical insertion of the ACL. A significant correlation (P < 0.05) was found between femoral placement of the graft in the sagittal plane and clinical results: the IKDC score declined with increasing distance of the graft from the most isometric bundle of the ACL in the anteroposterior direction.

Dynamic hip screw with trochanteric stabilizing plate in the treatment of unstable proximal femoral fractures: a comparative study with the Gamma nail and compression hip screw

OBJECTIVE

To compare the results after operative treatment of unstable per- and subtrochanteric fractures with the Gamma nail, compression hip screw (CHS), or dynamic hip screw with a laterally mounted trochanteric stabilizing plate (DHS/TSP).

DESIGN

Prospective.

PATIENTS

One hundred seventy patients with unstable trochanteric femoral fractures surviving six months after operation. Eighty-five patients were randomized to treatment with the Gamma nail (n = 50, Gamma group) or the compression hip screw (n = 35, CHS group) and compared with a consecutive series of eighty-five patients operated with the dynamic hip screw with a laterally mounted trochanteric stabilizing plate (DHS/TSP group)

MAIN OUTCOME MEASUREMENTS

Radiographs were analyzed for fracture classification, evaluation of fracture reduction, implant positioning, later fracture dislocation, and other complications. Pre- and postoperative functional status of the patients were recorded, with a minimum of six months follow-up.

RESULTS

Eighteen percent of the patients in the Gamma group, 34 percent in the CHS group, and 9 percent in the DHS/TSP group suffered significant secondary fracture dislocation during the six months follow-up, leading to a varus malunion, lag screw cutout, or excessive lag screw sliding with medialization of the distal fracture fragment. Two patients (4.0 percent) in the Gamma group suffered an implant-related femoral fracture below the nail, and one had a deep infection. The reoperation rates were 8.0 percent in the Gamma group, 2.9 percent in the CHS group, and 5.9 percent in the DHS/TSP group. All but one fracture in the Gamma and CHS groups and two fractures in the DHS/TSP group healed within six months. Approximately three-fourths of the patients had returned to their preoperative walking ability after six months, with a trend toward better functional outcome in the DHS/TSP group. Use of a TSP reduced the secondary lag screw sliding as compared with the conventional CHS, without affecting fracture healing.

CONCLUSION

The TSP may be an aid in the treatment of these difficult fractures because the problem with femoral shaft fractures using the Gamma nail is avoided and the medialization of the distal fracture fragment frequently associated with the CHS is prevented.

Joint hypermobility and genetic collagen disorders: are they related?

The HDCTs constitute a heterogeneous group of rare genetically determined diseases, the best known of which are Ehlers-Danlos and Marfan syndromes and osteogenesis imperfecta. Hypermobility is a feature common to them all, but it is also a feature that is highly prevalent in the population at large. Symptomatic hypermobile subjects (whose symptoms are attributable to their hypermobility) are said to be suffering from the benign joint hypermobility syndrome, which has many features that overlap with the HDCTs. It is not yet known whether there is a variety of hypermobility (symptomatic or otherwise) that is not part of a connective tissue disorder.

Classification and evaluation of recurrent instability of the elbow

The clinical presentation, diagnosis, radiographic features, mechanism, pathologic changes, and treatment of elbow instability are understood better now. Elbow instability can be classified according to five criteria: (1) the timing (acute, chronic or recurrent); (2) the articulation(s) involved (elbow versus radial head); (3) the direction of displacement (valgus, varus, anterior, posterolateral rotatory); (4) the degree of displacement (subluxation or dislocation); and (5) the presence or absence of associated fractures. Posterolateral rotatory instability is the most common pattern of elbow instability, particularly that which is recurrent. Posterolateral rotatory instability can be considered a spectrum consisting of three stages according to the degree of soft tissue disruption. Patients typically present with a history of recurrent painful clicking, snapping, clunking, or locking of the elbow and careful examination reveals that this occurs in the extension portion of the arc of motion with the forearm in supination. There are four principle physical examination tests. The most sensitive is the lateral pivot-shift apprehension test, or posterolateral rotatory apprehension test, just as the anterior apprehension test of the shoulder is the most sensitive test for a patient with shoulder instability. Next is the lateral pivot-shift test, or posterolateral rotatory instability test. Reproducing the actual subluxation and the clunk that occurs with reduction usually can be accomplished only with the patient under general anesthesia or occasionally after injecting local anesthetic into the elbow. The third test is the posterolateral rotatory drawer test, which is a rotatory version of the drawer or Lachman test of the knee. The final test is the stand up test as reported by Regan. The patient's symptoms are reproduced as he or she attempts to stand up from the sitting position by pushing on the seat with the hand at the side and the elbow fully supinated. A lateral stress radiograph can show the rotatory subluxation.

Scapholunate ligament reconstruction using a bone-retinaculum-bone autograft

This study was designed to evaluate the use of a locally available bone-retinaculum-bone graft in the reconstruction of the completely torn scapholunate (SL) ligament. Nineteen consecutive patients (14 with dynamic instability and 5 with static instability) underwent SL ligament reconstruction using an autogenous bone-retinaculum-bone graft taken from the third dorsal compartment region. All patients underwent arthroscopy to document a torn SL ligament. The bone plugs on the graft were fitted into the dorsal scaphoid and lunate, respectively, with the retinaculum periosteal soft tissue intervening sleeve arching between these 2 bones. The SL interval was reduced and pinned for 8 weeks with cast immobilization. The follow-up period averaged 3.6 years (minimum, 24 months). Of the 14 patients with dynamic instability, 12 had no pain and 2 had pain with heavy activity of the wrist. Range of motion (ROM) decreased slightly from preoperative values, and grip strength improved 46%. Thirteen patients were completely satisfied and returned to their former work activities, and 1 returned to modified work activities. Of the 5 patients with static instability, 2 had no pain after surgery, 1 had pain with heavy activity, and 2 had constant pain. ROM in this group decreased moderately in extension/flexion from the preoperative values. Grip strength improved 30% from preoperative values. Satisfaction was rated as complete by 1 patient and partial by 2 patients; 2 patients were dissatisfied. Two patients returned to their former jobs, 2 returned to modified duties, and 1 is on disability. Reconstruction of the SL ligament using a bone-retinaculum-bone autograft is predictable in patients with dynamic instability. Use of this technique with static SL instability is questionable; these patients may require a stronger construct to prevent recurrence of the SL gap.

Anterior shoulder instability: accuracy of MR arthrography in the classification of anteroinferior labroligamentous injuries

PURPOSE

To retrospectively evaluate the accuracy of magnetic resonance (MR) arthrography in the classification of anteroinferior labroligamentous injuries by using arthroscopy as the reference standard.

MATERIALS AND METHODS

Ethical committee approval and informed consent were obtained. MR arthrograms obtained in 205 patients, including a study group of 104 patients (74 male and 30 female; mean age, 28.2 years) with arthroscopically proved labroligamentous injuries and a control group of 101 patients (65 male and 36 female; mean age, 31.4 years) with intact labroligamentous complex, were reviewed in random order. MR arthrograms were analyzed for the presence and type (Bankart, anterior labral periosteal sleeve avulsion [ALPSA], Perthes, glenolabral articular disruption [GLAD], or nonclassifiable lesion) of labroligamentous injuries by two radiologists in consensus. Results were compared with arthroscopic findings. Sensitivity, specificity, accuracy, and corresponding 95% confidence intervals for the detection and classification of anteroinferior labroligamentous lesions with MR arthrography were calculated.

RESULTS

At arthroscopy, 104 anteroinferior labroligamentous lesions were diagnosed, including 44 Bankart lesions, 22 ALPSA lesions, 12 Perthes lesions, and three GLAD lesions. Twenty-three labral lesions were nonclassifiable at arthroscopy, all of which occurred after a history of chronic instability. Nineteen (83%) of these 23 lesions were also nonclassifiable at MR arthrography. With arthroscopy used as the reference standard, labroligamentous lesions were detected and correctly classified at MR arthrography with sensitivities of 88% and 77%, specificities of 91% and 91%, and accuracies of 89% and 84%, respectively. Bankart, ALPSA, and Perthes lesions were correctly classified in 80%, 77%, and 50% of cases, respectively. The three GLAD lesions were all correctly assessed.

CONCLUSION

MR arthrography is accurate in enabling classification of acute and chronic anteroinferior labroligamentous injuries, although correct interpretation of Perthes lesions remains difficult.

Grading the pivot shift. Objective tests with implications for treatment

A logical, objective and reproducible grading system for the pivot shift test is proposed. The rationale is based on performing the examination in varying positions of rotation of the tibia, allowing the type and degree of the different laxities to be defined and quantified. The system has been assessed against a new "unblocked" test for anterior subluxation and against radiographic measurements, operative findings and results. This grading system can be valuable in pre-operative assessment and planning and its use in postoperative evaluation would enable results from different centres and different procedures to be compared more accurately.

Measurement properties of clinical assessment methods for classifying generalized joint hypermobility-A systematic review

The purpose was to perform a systematic review of clinical assessment methods for classifying Generalized Joint Hypermobility (GJH), evaluate their clinimetric properties, and perform the best evidence synthesis of these methods. Four test assessment methods (Beighton Score [BS], Carter and Wilkinson, Hospital del Mar, Rotes-Querol) and two questionnaire assessment methods (Five-part questionnaire [5PQ], Beighton Score-self reported [BS-self]) were identified on children or adults. Using the Consensus-based Standards for selection of health Measurement Instrument (COSMIN) checklist for evaluating the methodological quality of the identified studies, all included studies were rated "fair" or "poor." Most studies were using BS, and for BS the reliability most of the studies showed limited positive to conflicting evidence, with some shortcomings on studies for the validity. The three other test assessment methods lack satisfactory information on both reliability and validity. For the questionnaire assessment methods, 5PQ was the most frequently used, and reliability showed conflicting evidence, while the validity had limited positive to conflicting evidence compared with test assessment methods. For BS-self, the validity showed unknown evidence compared with test assessment methods. In conclusion, following recommended uniformity of testing procedures, the recommendation for clinical use in adults is BS with cut-point of 5 of 9 including historical information, while in children it is BS with cut-point of at least 6 of 9. However, more studies are needed to conclude on the validity properties of these assessment methods, and before evidence-based recommendations can be made for clinical use on the "best" assessment method for classifying GJH. © 2017 Wiley Periodicals, Inc.

Lateral compartment translation predicts the grade of pivot shift: a cadaveric and clinical analysis

Anterior translation of the lateral compartment was hypothesized to correlate with the clinical grade of a pivot shift maneuver. Using a computer-assisted navigation system, this hypothesis was tested by recording the maximum anterior tibial translation in the medial and lateral compartment as well as the arc of rotation during the pivot shift maneuver. One hundred and fifty-four pivot shift examinations were performed on cadavers with various degrees of instability, and 24 pivot shift exams were performed on patients under anesthesia before and after ACL reconstruction. In all positive pivot shift exams, anterior tibial translations were found to be higher on in the lateral compartment compared to the medial compartment. In addition, an excellent correlation was found between the amount of lateral compartment translation and the clinical grade of the pivot shift; medial compartment translations and amount of knee rotation could not distinguish between clinical grades. Finally, a threshold of 6-7 mm of anterior tibial translation in the lateral compartment was necessary to produce a positive pivot shift. Taken together, these data suggest that monitoring lateral compartment translations during a pivot shift exam may be a convenient means to evaluate the outcomes of ACL surgery and that requisite increases in anterior translation of the lateral compartment are necessary for each progressive clinical grade of the pivot shift examination.

Segmental instability. Rationale for treatment

Segmental instability, secondary to spinal degeneration, is a controversial topic. Based on current clinical, radiographic, and biomechanical considerations, this condition is classified as axial rotational, translational, retrolisthetic, and postsurgical instability syndromes. Each of these conditions would be expected, if untreated, to progress to a fixed deformity in which the clinical symptoms of spinal stenosis would predominate. The classification of these four types of instability suggests a need for specifically tailored fusion techniques in those patients who fail to respond to conservative treatment. Antitorsion facet fusion is suggested for axial rotatory instabilities; anterior (or posterior) interbody fusion for translational instabilities; and fusion in flexion (Knodt rods or facet fusion) for retrolisthetic instabilities. Post-surgical instability syndromes require carefully selected approaches based on the overall pathology. Application of specific fusion techniques, in carefully selected patients, may improve the currently unacceptable low rate of success from such operations.

Arthroscopic Bankart procedure: two- to five-year followup with clinical correlation to severity of glenoid labral lesion

We report our results using the arthroscopic Bankart technique described by Morgan (transglenoid suture) on 60 consecutive patients with anterior instability. All had detachment of the glenoid labrum at surgery. Forty-seven patients were available for final followup, which ranged from 2 to 5 years. Of these patients, 18 had experienced recurrent dislocation and 3 had experienced episodes of subluxation after surgery, for an overall failure rate of 42%. Partway into the study, we began to correlate severity of glenoid labral lesion with outcome. We classified the labral lesion in 37 patients using stringent criteria at the time of surgery. Followup among these patients averaged 37 months. Of 22 cases of simple detachment of the labrum with no other significant lesion (Type II labrum), there was one failure (4.5%). Of the 15 cases with significant or complete degeneration of the glenoid labrum-inferior glenohumeral ligament complex (Types IV or V labra), 13 failed (87%). Of the patients without recurrent instability, loss of external rotation averaged 1.5 degrees, strength was 5+/5+ in abduction and external rotation. Average postoperative function was 94% of preinjury levels subjectively, and most patients were able to return to previous activities, including throwing and other overhead sports. Our findings indicate that rates of redislocation after this arthroscopic Bankart procedure correlate directly with the degree of glenoid labrum-inferior glenohumeral ligament complex lesion.

Treatment of grade III acromioclavicular joint injuries: a systematic review

Although nonoperative treatment is considered the standard of care for the treatment of Grade I and II acromioclavicular (AC) joint injuries, the treatment of Grade III injuries is controversial. There are as many methods of nonoperative treatment as there are for operative stabilization. Most of the literature represents Level IV evidence with very few Level II and III studies upon which to base decisions. A systematic review of the English-language literature was performed to determine if Grade III AC joint separations are best treated operatively or nonoperatively. Based on limited low-evidence, nonoperative treatment was deemed more appropriate than traditional nonoperative treatments because the results of the latter were not clearly better and were associated with higher complication rates, longer convalescence, and longer time away from work and sport.

Arthroscopic repair of anterosuperior (supraspinatus/subscapularis) rotator cuff tears: a prospective cohort with 2- to 4-year follow-up. Classification of biceps subluxation/instability

PURPOSE

The purpose of this study was to evaluate the outcome of patients who underwent arthroscopic repair of anterosuperior rotator cuff tears. The null hypothesis, that there was no difference between preoperative scores and postoperative scores, was tested statistically.

TYPE OF STUDY

A cohort study.

METHODS

The preoperative and postoperative status of patients with anterosuperior rotator cuff tears was analyzed using the Constant score, American Shoulder and Elbow Society Index (ASES Index), a visual analog pain scale (VAS), a single question of percent function compared with the opposite unaffected extremity, and a single question reflecting satisfaction, "would you undergo the surgery and the postoperative rehabilitation to achieve the result you have today." There were also 2 groups compared: 1 that had a "tac" used for repair of the subscapularis tendon, and the other that used a "tie" technique for subscapularis repair. All supraspinatus tendon tears were complete and were repaired using a soft-tissue fixation device.

RESULTS

There was a statistically significant difference for all outcome measures except for the objective Constant score of the tie group, P =.58. Follow-up was 2 to 4 years. There were no differences based on sex or type of fixation device used for repair of the subscapularis tendon. There were no reruptures, clinically.

CONCLUSIONS

The arthroscopic repair of anterosuperior rotator cuff tears provides reliable expectation for improvement in function, decreases in pain, decreases in clinical findings of biceps subluxation and inflammation, improvement in shoulder scores, and the improvement of clinical findings of subscapularis insufficiency.

Long-term results of lateral retinacular release

PURPOSE

We evaluated the outcomes of lateral retinacular release (LRR) after a long-term follow-up period of 5 to 12 years.

TYPE OF STUDY

Long-term retrospective clinical follow-up study.

PATIENTS AND METHODS

Between 1986 and 1994, 120 LRRs were performed in the Orthopaedic Department of the Catholic University of Rome. A total of 100 patients were evaluated. We divided the patients into 2 groups: group I contained 50 patients with patellar pain and no signs of instability; the remaining 50 patients, with clear signs of patellar instability, made up group II. Standard weight-bearing radiographs, axial views of the knee at 45 degrees , and dynamic computed tomography scans were performed in all patients preoperatively and at follow-up evaluation. Chondral damage was classified at the time of lateral release according to the criteria of Outerbridge and Dunlop. We used the Lysholm II score, which was modified for patellofemoral pathology and a clinical grading system of Busch and de Haven, to evaluate clinical outcomes at follow-up evaluation.

RESULTS

In group I (pain), 70% reported satisfactory outcomes at follow-up evaluation compared with 50% in group II (P < .05) (instability). Compared with a previously published analysis of 3-year outcomes in this same patient population, there was very little change in group I patients, whereas group II showed a significant decrease in good outcomes over time. The worst results were obtained in cases with serious cartilage damage and exposure of the subchondral bone at the time of lateral release.

CONCLUSIONS

LRR is a procedure offering a good percentage of success in the management of a stable patella with excessive lateral pressure and elective location of pain on the lateral retinaculum. In patellar instability the results are less favorable in long-term follow-up evaluation. The presence of high-grade joint surface injury is a poor prognostic indicator for lateral release.

LEVEL OF EVIDENCE

Level IV.

Classification and preoperative radiographic evaluation: knee

Preoperative radiographic planning for revision total knee arthroplasty begins with obtaining excellent quality AP and lateral radiographs that permit: 1. Evaluation of the extent of bone loss in the metaphyseal region of the femur and tibia. 2. Full visualization of the patient's intramedullary canal for determining appropriate stem size and length. The surgeon should then determine the appropriate bone defect classification, keeping in mind the provisions needed to address Type 2 and 3 defects. These provisions include any augments or allografts, stemmed components, and the degree of component constraint needed in the patient's revision surgery. Through preoperative templating, the surgeon can determine whether a particular implant system provides the options necessary to achieve an optimal surgical result. Whenever templating leaves unanswered questions regarding the extent of bone damage or the degree of knee instability, the surgeon must prepare for the worst case scenario to ensure that the appropriate components and graft material are made available.

Classification and treatment of shoulder dysfunction in the overhead athlete

There are two distinct pathological categories of shoulder injury. In the older population, shoulder injury is generally a result of the degenerative aging process. In the younger population, it is commonly a result of the repetitiousness of an overhead sport. In the latter group, instability is typically the core problem, leading to the continuum of subluxation, impingement, and rotator cuff tear. A classification scheme, proposing four definitive types of shoulder injury, assists in directing an effective management program. Once diagnosed (the first step of treatment) a conservative rehabilitation program that emphasizes strengthening of the glenohumeral protectors, scapulohumeral pivotors, humeral positioners, and power drivers is advised. The surgery of choice, for the small minority who fail to respond to the rehabilitation program, is the anterior capsulolabral reconstruction. A sports medicine team working together with the athlete is instrumental in his/her return to sport.

Analysis of carpal instability: I. Description of the scheme

There is a lack of a generally agreed analysis of carpal instability that can assist in the diagnosis, give guidelines for treatment, and ensure unity when reporting results of treatment. Based on the literature and using six categories describing chronicity, constancy, etiology, location, direction, and pattern of the instability, we present a proposal for a standardized analysis. Using this analysis, an instability should be presented with information in all six categories. The analysis may be expanded and developed according to future needs.

SLAP lesions in the overhead athlete

The authors report an 87% rate of return to preinjury levels of throwing in 54 baseball players and an 84% rate of return to preinjury performance levels in pitches after repair of type II SLAP lesions. The etiology, biomechanics, surgical repair, and rehabilitation are discussed in detail.

Tibiofemoral instability in primary total knee replacement: a review, Part 1: Basic principles and classification

Tibiofemoral instability following total knee replacement has received little attention. However it is a cause of early and late failure and usually requires revision surgery. Several factors may be implicated including improper soft tissue balancing, flexion-extension gap mismatch and acute ligamentous injuries. Meticulous surgical technique and proper prosthetic selection at the primary procedure avoids this complication.

Evaluation of the walking pattern in two types of patients with anterior cruciate ligament deficiency: copers and non-copers

The purpose of the present study was to investigate whether different walking patterns in healthy subjects and in coper and non-coper subjects with deficient anterior cruciate ligaments could be quantified. An inverse dynamics approach was used to calculate joint kinematics and kinetics for flexion and extension. EMG signals of the hamstrings and quadriceps muscles were recorded. The results showed that the peak knee flexion angle was greater in the copers than in the controls. There was a positive correlation between the peak knee extensor moment and peak knee flexion angle. Furthermore, at a given peak knee flexion angle, the peak knee extensor moment was significantly larger in the controls than in the non-copers. The hip extensor moment in the copers was significantly larger than that of the non-copers and the controls. In conclusion, the three groups walked according to different patterns. It is suggested that the copers stabilized their knee joint by co-contraction of the hamstrings and quadriceps muscles, while the non-copers lacked this ability. Instead, the non-copers reduced the knee extensor moment in order to decrease anterior displacement of the tibia. The walking pattern differences observed between the copers and non-copers may explain their different post-injury activity levels.