Epidemiology and natural history of acute patellar dislocation

BACKGROUND

The goals of this study were to (1) define the epidemiology of acute patellar dislocation, (2) determine the risk of subsequent patellar instability episodes (subluxation and/or redislocation) during the study period, and (3) identify risk factors for subsequent instability episodes.

STUDY DESIGN

Prospective cohort study.

METHODS

The authors prospectively followed 189 patients for a period of 2 to 5 years. Historical data, injury mechanisms, and physical and radiographic measurements were recorded to identify potential risk factors for poor outcomes.

RESULTS

Risk was highest among females 10 to 17 years old. Patients presenting with a prior history of instability were more likely to be female (P < .05) and were older than first-time dislocation patients (P < .05). Fewer first-time dislocators (17%) had episodes of instability during follow-up than patients with a previous history of instability (49%) (P < .01). After adjusting for demographics, patients with a prior history had 7 times higher odds of subsequent instability episodes during follow-up than first time dislocators (adjusted odds ratio = 6.6, P < .001).

CONCLUSIONS

Patellar dislocators who present with a history of patellofemoral instability are more likely to be female, are older, and have greater risk of subsequent patellar instability episodes than first-time patellar dislocators. Risk of recurrent patellar instability episodes in either knee is much higher in this group than in first-time dislocators.

The inverted pear glenoid: an indicator of significant glenoid bone loss

PURPOSE

The purpose of this study was to determine the amount of glenoid bone loss required to produce an inverted pear glenoid.

TYPE OF STUDY

Two-part anatomic study involving live subjects and cadaveric specimens.

METHODS

From June 2000 to April 2002, 53 patients (mean age, 30 +/- 13 years) underwent arthroscopic evaluation and treatment with a diagnosis of anterior instability by the senior author (S.S.B.). Each of these patients underwent a 3-portal diagnostic arthroscopy to determine the morphology of the glenoid. Glenoids were classified as either inverted pear or non-inverted pear glenoids based on the visual appearance. The amount of glenoid bone loss was then quantified arthroscopically using a validated methodology. In addition, 6 fresh-frozen cadaveric specimens (mean age, 74.1 +/- 7.4 years) were dissected and evaluated to determine the minimum amount of bone loss required to produce an inverted pear glenoid.

RESULTS

Forty-two patients were classified as having non-inverted pear glenoids and 11 patients were classified as having inverted pear glenoids. The mean amount of bone loss anteriorly was significantly more (P <.000006) in the inverted pear glenoid group (mean, 8.6 mm; range, 6 to 12 mm) than the non-inverted pear glenoid group (mean, 1.5 mm; range, 0 to 3.0 mm). The percentage of loss of glenoid width was also significantly different (inverted pear mean, 36%; range, 25% to 45% versus non-inverted pear mean, 6.2%; range, 0% to 12.5%; P <.000006). The mean amount of bone loss required in cadaveric specimens to convert a normal pear-shaped glenoid into an inverted pear glenoid was 7.5 mm (range, 6.5 to 9.0 mm), representing 28.8% of the glenoid width (range, 27% to 30%).

CONCLUSIONS

The results of this study show that the majority of patients with the diagnosis of anterior instability show some bone loss anteriorly. However, the inverted pear glenoid represents a significant amount of bone loss, at least 25% to 27% of the width of the inferior glenoid. In patients with an inverted pear glenoid, a bone grafting procedure to restore the normal articular arc of the glenoid should be strongly considered to re-establish normal stability to the shoulder.

Ligament reconstruction for the painful thumb carpometacarpal joint: a long-term assessment

An extra-articular ligament reconstruction to stabilize the thumb carpometacarpal (CMC) (basal) joint by routing a portion of the flexor carpi radialis (FCR) through the base of the thumb metacarpal has been performed on more than 100 patients since 1967. This study reviews the first 50 consecutive reconstructions with an average follow-up of 7 years. Intractable pain was the primary indication for surgery. Each joint was examined both pre and postoperatively and rated as a stage I through stage IV according to the radiographic appearance. Of the patients with zero or minimal articular changes (stages I and II), 95% achieved good or excellent results because of having little or no postoperative pain. Of the patients with moderate to advanced degenerative changes (stages III and IV), 74% achieved good or excellent results. All stage I cases and 82% of stage II cases were free of recognizable degeneration on follow-up radiographs up to 13 years postoperatively. These findings suggest that ligament reconstruction that is now recommended only for stage I or stage II disease will restore stability, reduce pain, and possibly even retard joint degeneration in a large proportion of patients with painful instability of the thumb CMC joint.

Quantifying glenoid bone loss arthroscopically in shoulder instability

PURPOSE

Our goal was to establish a consistent methodology for quantifying glenoid bone loss by arthroscopic means.

TYPE OF STUDY

This study was an anatomic investigation of glenoid structure and its consistent anatomic landmarks as determined by arthroscopic means in live subjects and by direct measurement in fresh-frozen cadaver specimens.

METHODS

We arthroscopically evaluated and measured the location of the bare spot of the glenoid in 56 subjects that had no evidence of instability (average age, 40 years). We also measured the exact location of the glenoid bare spot in 10 cadaver shoulders (average age, 76 years).

RESULTS

The bare spot of the glenoid was a consistent reference point from which to determine glenoid bone loss because it was located almost exactly at the center of the circle that was defined by the articular margin of the inferior glenoid below the level of the midglenoid notch. The tightly clustered standard deviations of the bare spot measurements in both the live subjects and the cadaver specimens confirmed its consistent location.

CONCLUSIONS

The glenoid bare spot can be used as a central reference point to quantify the percentage bone loss of the inferior glenoid. Such objective measurement of glenoid bone loss can be clinically useful to the surgeon in deciding whether bone grafting is necessary to restore stability to the shoulder with a bone-deficient glenoid.

The effects of generalized joint laxity on risk of anterior cruciate ligament injury in young female athletes

BACKGROUND

Women who participate in high-risk sports suffer anterior cruciate ligament injury at a 4- to 6-fold greater rate than men.

PURPOSE

To prospectively determine if female athletes with decreased passive knee joint restraint (greater joint laxity) and greater side-to-side differences in knee laxity would be at increased risk of anterior cruciate ligament injury.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

From 1558 female soccer and basketball players who were prospectively screened, 19 went on to tear their anterior cruciate ligaments. Four height- and mass-matched control subjects were selected from the uninjured screened athletes for comparison with each of the 19 injured subjects, making a total of 95 subjects (19 injured; 76 uninjured). Generalized joint-laxity tests and anterior-posterior tibiofemoral translation were quantified using the CompuKT knee arthrometer. A multivariable logistic regression model was constructed to determine predictors of anterior cruciate ligament injury status from recorded laxity measures.

RESULTS

A multivariable logistic regression model (chi-square = 18.6; P = .002) used the independent variables laxity measures of knee hyperextension (P = .02), wrist and thumb to forearm opposition (P = .80), fifth-finger hyperextension > 90 degrees (P = .71), side-to-side differences in anterior-posterior tibiofemoral translation (P = .002), and prior knee injury (P = .22) to predict anterior cruciate ligament-injury status. The validated C statistic, or validated area under the receiver operating characteristic curve, was 0.72. For every 1.3-mm increase in side-to-side differences in anterior-posterior knee displacement, the odds of anterior cruciate ligament-injured status increased 4-fold (95% confidence interval, 1.68-9.69). A positive measure of knee hyperextension increased the odds of anterior cruciate ligament-injured status 5-fold (95% confidence interval, 1.24-18.44).

CONCLUSION

The current results indicate that increased knee-laxity measures may contribute to increased risk of anterior cruciate ligament injury. The methods to quantify knee joint laxity in this report may be used in conjunction with measures of neuromuscular control of the knee joint to identify high-risk female athletes with high accuracy. Once high-risk female athletes are identified, they may be targeted to the appropriate interventions to reduce injury risk.

Contribution of runt-related transcription factor 2 to the pathogenesis of osteoarthritis in mice after induction of knee joint instability

OBJECTIVE

By producing instability in mouse knee joints, we attempted to determine the involvement of runt-related transcription factor 2 (RUNX-2), which is required for chondrocyte hypertrophy, in the development of osteoarthritis (OA).

METHODS

An experimental mouse OA model was created by surgical transection of the medial collateral ligament and resection of the medial meniscus of the knee joints of heterozygous RUNX-2-deficient (Runx2+/-) mice and wild-type littermates. Cartilage destruction and osteophyte formation in the medial tibial cartilage were compared by histologic and radiographic analyses. Localization of type X collagen and matrix metalloproteinase 13 (MMP-13) was examined by immunohistochemistry. Localization of RUNX-2 was determined by X-Gal staining in heterozygous RUNX-2-deficient mice with the lacZ gene insertion at the Runx2-deletion site (Runx2+/lacZ). Messenger RNA levels of type X collagen, MMP-13, and RUNX-2 were examined by real-time reverse transcriptase-polymerase chain reaction analysis.

RESULTS

RUNX-2 was induced in the articular cartilage of wild-type mice at the early stage of OA, almost simultaneously with type X collagen but earlier than MMP-13. Runx2+/- and Runx2+/lacZ mice showed normal skeletal development and articular cartilage; however, after induction of knee joint instability, they exhibited decreased cartilage destruction and osteophyte formation, along with reduced type X collagen and MMP-13 expression, as compared with wild-type mice.

CONCLUSION

RUNX-2 contributes to the pathogenesis of OA through chondrocyte hypertrophy and matrix breakdown after the induction of joint instability.

Positive pivot shift after ACL reconstruction predicts later osteoarthrosis: 63 patients followed 5-9 years after surgery

BACKGROUND

Rupture of the anterior cruciate ligament (ACL) may cause osteoarthrosis (OA) and functional impairment. We wanted to find out whether the degree of knee stability obtained after ACL reconstruction correlates with radiographic and clinical outcome.

PATIENTS AND METHODS

We examined 63 patients 2 and 5-9 years after anterior cruciate ligament (ACL) reconstruction. Knee stability was assessed 2 years after surgery by recording AP laxity using radiostereometric technique (RSA) and by performing the pivot shift test. Degeneration of the knee joint was evaluated with bone scintigraphy, and radiographically. Functional outcome was assessed with Lysholm score, Tegner activity scale and with the one-leg hop test.

RESULTS

Radiographic signs of osteoarthrosis at the most recent follow-up (5-9 years) did not correlate with knee stability. Patients with positive pivot shift test 2 years after surgery showed increased scintigraphic activity of the subchondral bone at the most recent follow-up, and inferior subjective functional outcome 2 years after surgery. Knees having had meniscus resections had more often OA. Radiographical signs of OA were associated with higher scintigraphic uptake in the operated knee relative to the contralateral knee.

INTERPRETATION

The ability to obliterate the pivoting by ACL reconstruction appears to be more important than normalizing the AP laxity in order to prevent later OA.

A comparison of the spectrum of intra-articular lesions in acute and chronic anterior shoulder instability

PURPOSE

The purpose of the study was to compare the incidence of secondary intra-articular shoulder lesions in patients with acute and chronic anterior shoulder instability. The occurrence of glenoid shape alterations (inverted pear glenoid) in recurrent instability was especially examined.

METHODS

Data for all arthroscopically ascertained intra-articular shoulder lesions in a series of 127 patients with acute and chronic traumatic anterior instability were recorded.

RESULTS

Hemarthrosis was evident in all patients with acute dislocation and in 7 patients with chronic laxity who underwent surgery shortly after a dislocation episode. In both groups the presence of a chondral or osteochondral Hill-Sachs lesion was noted in 112 patients (88.1%), a Bankart lesion was noted in 106 patients (83.46%), an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion was noted in 13 patients (10.23%), a SLAP lesion was noted in 26 patients (20.47%), a humeral avulsion of the glenohumeral ligament (HAGL) lesion was noted in 2 acutely dislocated shoulders (1.57%), and capsular laxity was noted in 33 patients (25.98%). All ALPSA lesions were noted in patients with chronic instability (P = .044), and both HAGL lesions were found in patients with acute dislocations (P = .002). In patients with acute dislocations the incidence of Bankart lesions was 78.2% (18/23), whereas in chronic cases the incidence of Bankart or ALPSA lesions was 97.11% (101/104) (P = .002). In the group with acute dislocations there was a Hill-Sachs lesion in 15 cases (65.21%) and chronic recurrent instability accounted for 97 cases (93.26%) (P = .001). The capsule was considered lax in 2 patients with acute instability and 31 patients with chronic instability (8.69% v 29.8%, P = .037). The overall frequency of SLAP lesions was not statistically significant between acute and chronic cases (P = .868), unlike their distribution. In acute cases there were 3 type I and 2 type II SLAP lesions, whereas in chronic cases there were 4 type I, 13 type II, 3 type III, and 1 type IV SLAP lesions. Loose bodies were found and removed in 17 chronic and 4 acute cases (16.34% v 13.04%, P = .903). A partial-thickness articular rotator cuff tear was found in 14 patients: 12 with chronic dislocations and 2 with acute dislocations (11.53% v 8.69%, P = .694). The cuff tears were partial articular surface tears, involving less than 25% of the cuff thickness, and were treated with debridement, and cuff repair was not necessary in any case. The inverted pear configuration of the glenoid was found in 16 cases with chronic instability (15.38%), whereas no patient with an acutely dislocated shoulder had an inverted pear-shaped glenoid (P = .044).

CONCLUSIONS

Associated, secondary intra-articular lesions are more frequent in patients with chronic compared with acute shoulder instability, probably as a result of the repeated dislocation or subluxation episodes.

LEVEL OF EVIDENCE

Level IV, prognostic case series.

Medial patellofemoral ligament reconstruction in patients with lateral patellar instability and trochlear dysplasia

BACKGROUND

Reconstruction of the medial patellofemoral ligament has been proven to restore stability in patients with lateral patellar instability. No study to date has examined the results in a patient population with the predisposing factor of femoral trochlear dysplasia.

HYPOTHESIS

Reconstruction of the medial patellofemoral ligament restores stability and provides pain relief in patients who have lateral patellar instability in association with trochlear dysplasia.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Thirty-four patients with chronic patellar instability and trochlear dysplasia were treated with medial patellofemoral ligament reconstruction using an adductor tendon autograft, bone-quadriceps tendon autograft, or bone-patellar tendon allograft. All patients were evaluated preoperatively and postoperatively with Kujala, Lysholm, and Tegner scores at a minimum of 24 months.

RESULTS

Thirty-four patients were followed for a mean of 66.5 months (range, 24-130 months) after surgery. Kujala scores improved from 53.3 to 90.7, Lysholm scores improved from 52.4 to 92.1, and Tegner activity scores improved from 3.1 to 5.1. All improvements were highly statistically significant (P < .001). No statistical difference was found between the postoperative Lysholm, Kujala, and Tegner scores and the degree of dysplasia, graft type, or degree of symptoms. There were 85.3% and 91.1% good and excellent results based on Kujala and Lysholm scores, respectively. No recurrent dislocations have occurred.

CONCLUSION

Medial patellofemoral ligament reconstruction provides excellent long-term pain relief and functional return in patients with patellar instability and femoral trochlear dysplasia. In addition, reconstruction prevents recurrent dislocation, despite the diminished bony constraint of a dysplastic trochlea.

Joint hypermobility syndrome in childhood. A not so benign multisystem disorder?

OBJECTIVES

Joint hypermobility (JH) or "ligamentous laxity" is felt to be an underlying risk factor for many types of musculoskeletal presentation in paediatrics, and joint hypermobility syndrome (JHS) describes such disorders where symptoms become chronic, often more generalized and associated with functional impairment. Clinical features are felt to have much in common with more severe disorders, including Ehlers-Danlos syndrome (EDS), osteogenesis imperfecta and Marfan syndrome, although this has not been formally studied in children. We defined the clinical characteristics of all patients with joint hypermobility-related presentations seen from 1999 to 2002 in a tertiary referral paediatric rheumatology unit.

METHODS

Patients were identified and recruited from paediatric rheumatology clinic and ward, and a dedicated paediatric rheumatology hypermobility clinic at Great Ormond Street Hospital. Data were collected retrospectively on the patients from the paediatric rheumatology clinics (1999-2002) and prospectively on patients seen in the hypermobility clinic (2000-2002). Specifically, historical details of developmental milestones, musculoskeletal or soft tissue diagnoses and symptoms, and significant past medical history were recorded. Examination features sought included measurements of joint and soft tissue laxity, and associated conditions such as scoliosis, dysmorphic features, cardiac murmurs and eye problems.

RESULTS

One hundred and twenty-five children (64 females) were included on whom sufficient clinical data could be identified and who had clinical problems ascribed to JH present for longer than 3 months. Sixty-four were from the paediatric rheumatology clinic and 61 from the hypermobility clinic. No differences were found in any of the measures between the two populations and results are presented in a combined fashion. Three-quarters of referrals came from paediatricians and general practitioners but in only 10% was hypermobility recognized as a possible cause of joint complaint. The average age at onset of symptoms was 6.2 yr and age at diagnosis 9.0 yr, indicating a 2- to 3-yr delay in diagnosis. The major presenting complaint was arthralgia in 74%, abnormal gait in 10%, apparent joint deformity in 10% and back pain in 6%. Mean age at first walking was 15.0 months; 48% were considered "clumsy" and 36% as having poor coordination in early childhood. Twelve per cent had "clicky" hips at birth and 4% actual congenital dislocatable hip. Urinary tract infections were present in 13 and 6% of the female and male cases, respectively. Thirteen and 14%, respectively, had speech and learning difficulties diagnosed. A history of recurrent joint sprains was seen in 20% and actual subluxation/dislocation of joints in 10%. Forty per cent had experienced problems with handwriting tasks, 48% had major limitations of school-based physical education activities, 67% other physical activities and 41% had missed significant periods of schooling because of symptoms. Forty-three per cent described a history of easy bruising. Examination revealed that 94% scored > or =4/9 on the Beighton scale for generalized hypermobility, with knees (92%), elbows (87%), wrists (82%), hand metacarpophalangeal joints (79%), and ankles (75%) being most frequently involved.

CONCLUSIONS

JHS is poorly recognized in children with a long delay in the time to diagnosis. Although there is a referral bias towards joint symptoms, a surprisingly large proportion is associated with significant neuromuscular and motor development problems. Our patients with JHS also show many overlap features with genetic disorders such as EDS and Marfan syndrome. The delay in diagnosis results in poor control of pain and disruption of normal home life, schooling and physical activities. Knowledge of the diagnosis and simple interventions are likely to be highly effective in reducing the morbidity and cost to the health and social services.

Laxity in healthy and osteoarthritic knees

OBJECTIVE

Although it is a cause of osteoarthritis (OA) in animal models, laxity in human knee OA has been minimally evaluated. Ligaments become more compliant with age; whether this results in clinical laxity is not clear. In theory, laxity may predispose to OA and/or result from OA. Our goals were to examine the correlation of age and sex with knee laxity in control subjects without OA, compare laxity in uninvolved knees of OA patients with that in older control knees, and examine the relationship between specific features of OA and knee laxity.

METHODS

We assessed varus-valgus and anteroposterior laxity in 25 young control subjects, 24 older control subjects without clinical OA, radiographic OA, or a history of knee injury, and 164 patients with knee OA as determined by the presence of definite osteophytes. A device was designed to assess varus-valgus laxity under a constant varus or valgus load while maintaining a fixed knee flexion angle and thigh and ankle immobilization. Radiographic evaluations utilized protocols addressing position, beam alignment, magnification, and landmark definition; the semiflexed position was used, with fluoroscopic confirmation.

RESULTS

In the controls, women had greater varus-valgus laxity than did men (3.6 degrees versus 2.7 degrees; 95% confidence interval [95% CI] of difference 0.38, 1.56; P = 0.004), and laxity correlated modestly with age (r = 0.29, P = 0.04). Varus-valgus laxity was greater in the uninvolved knees of OA patients than in older control knees (4.9 degrees versus 3.4 degrees; 95% CI of difference 0.60, 2.24; P = 0.0006). In OA patients, varus-valgus laxity increased as joint space decreased (slope -0.34; 95% CI -0.48, -0.19; P < 0.0001) and was greater in knees with than in knees without bony attrition (5.3 degrees versus 4.5 degrees; 95% CI of difference 0.32, 1.27; P = 0.001).

CONCLUSION

Greater varus-valgus laxity in the uninvolved knees of OA patients versus older control knees and an age-related increase in varus-valgus laxity support the concept that some portion of the increased laxity of OA may predate disease. Loss of cartilage/bone height is associated with greater varus-valgus laxity. These results raise the possibility that varus-valgus laxity may increase the risk of knee OA and cyclically contribute to progression.

Association of glenoid labral cysts with labral tears and glenohumeral instability: radiologic findings and clinical significance

PURPOSE

To determine the relationship between labral cysts and labral tears and glenohumeral instability.

MATERIALS AND METHODS

Magnetic resonance (MR), clinical, and arthroscopic examinations of the shoulder and the surgical findings of 20 patients were correlated and retrospectively analyzed. A cystic-appearing mass adjacent to the labrum was the selection criterion for inclusion.

RESULTS

MR imaging showed labral tear intimately associated with cystic-appearing mass in these 20 patients. The tear and cyst complex was located anteriorly in two patients, posteriorly in nine, and superiorly in nine. The mass extended into the spinoglenoid notch in six patients, the suprascapular notch in three, and both notches in four. Physical examination showed glenohumeral instability in the direction of the labral tear and cystic-appearing mass in 11 patients (55%). Findings at intraarticular surgery, performed in eight patients, confirmed a labral tear with communication between the joint space and the cyst.

CONCLUSION

Glenoid labral cysts are associated with glenoid labral tears and shoulder instability.

Associated injuries found in chronic lateral ankle instability

Sixty-one patients underwent a primary ankle lateral ligament reconstruction for chronic instability between 1989 and 1996. In addition to the ligament reconstruction, all patients had evaluation of the peroneal retinaculum, peroneal tendon inspection by routine opening of the tendon sheath, and ankle joint inspection by arthrotomy. A retrospective review of the clinical history, physical exam, MRI examination, and intraoperative findings was conducted on these 61 patients. The purpose was to determine the type and frequency of associated injuries found at surgery and during the preoperative evaluation. At surgery no patients were found to have isolated lateral ligament injury. Fifteen different associated injuries were noted. The injuries found most often by direct inspection included: peroneal tenosynovitis, 47/61 patients (77%); anterolateral impingement lesion, 41/61 (67%); attenuated peroneal retinaculum, 33/61 (54%); and ankle synovitis, 30/61 (49%). Other less common but significant associated injuries included: intra-articular loose body, 16/61 (26%); peroneus brevis tear, 15/61 (25%); talus osteochondral lesion, 14/61 (23%); medial ankle tendon tenosynovitis, 3/61 (5%). The findings of this study indicate there is a high frequency of associated injuries in patients with chronic lateral ankle instability. Peroneal tendon and retinacular pathology, as well as anterolateral impingement lesions, occur most often. A high index of suspicion for possible associated injuries may result in more consistent outcomes with nonoperative and operative treatment of patients with chronic lateral ankle instability.

Lumbar intervertebral instability: a review

Intervertebral instability of the lumbar spine is thought to be a possible pathomechanical mechanism underlying low back pain and sciatica and is often an important factor in determining surgical indication for spinal fusion and decompression. Instability of the lumbar spine, however, remains a controversial and poorly understood topic. At present, much controversy exists regarding the proper definition of the condition, the best diagnostic methods, and the most efficacious treatment approaches. Clinical presentation is not specific, and the relationship between radiologic evidence of instability and its symptoms is controversial. Because of its simplicity, low expense, and pervasive availability, functional flexion-extension radiography is the most thoroughly studied and the most widely used method in the imaging diagnosis of lumbar intervertebral instability. In this article, we provide an overview of the current concepts of vertebral instability, focusing on degenerative lumbar intervertebral instability, and review the different imaging modalities most indicated in diagnosing vertebral instability.

Lumbar repositioning deficit in a specific low back pain population

STUDY DESIGN

A cross-sectional observational design study was conducted to determine lumbar repositioning error in 15 subjects who had chronic low back pain with a clinical diagnosis of lumbar segmental instability and 15 asymptomatic participants.

OBJECTIVE

To determine whether individuals with lumbar segmental instability have a decreased ability to reposition their lumbar spine into a neutral spinal position.

SUMMARY OF BACKGROUND DATA

Proprioception of the lumbar spine has been investigated in individuals who have low back pain with variable results. The testing procedure's lack of sensitivity and the nonhomogeneity of groups may be responsible for the conflicting findings.

METHODS

Repositioning accuracy of the lumbar spine was assessed using the 3Space Fastrak to determine error in 15 participants with lumbar segmental instability and 15 asymptomatic subjects. The participants were assisted into a neutral spinal sitting posture and then asked to reproduce this position independently over five trials separated by periods of relaxed full lumbar flexion.

RESULTS

Lumbosacral repositioning error was significantly greater in participants with lumbar segmental instability than in the asymptomatic group (t[28] = 2.48; P = 0.02. There also was a significant difference between the groups at each individual sensor.

CONCLUSIONS

The results of this study indicate that individuals with a clinical diagnosis of lumbar segmental instability demonstrate an inability to reposition the lumbar spine accurately into a neutral spinal posture while seated. This finding provides evidence of a deficiency in lumbar proprioceptive awareness among this population.

Neuromuscular training improves single-limb stability in young female athletes

STUDY DESIGN

Controlled single-group pretest/posttest design.

OBJECTIVE

The purpose of this study was to determine if a 6-week neuromuscular training program designed to decrease the incidence of anterior cruciate ligament (ACL) injuries would improve single-limb postural stability in young female athletes. We hypothesized neuromuscular training would result in an improvement in postural stability, with the greatest improvement taking place in the medial-lateral direction.

BACKGROUND

Balance training has become a common component of programs designed to prevent ACL injury. Rehabilitation programs can improve postural stability following ACL injury and reconstruction; however, there is limited information available which quantifies improvement of postural stability following neuromuscular training designed to prevent ACL injuries in a healthy population.

METHODS AND MEASURES

Forty-one healthy female high school athletes (mean age, 15.3 years; age range, 13-17 years) participated in this study. Single-limb postural stability for both lower extremities was assessed with a Biodex Stability System. The neuromuscular training program consisted of three 90-minute training sessions per week for 6 weeks. Following the completion of the training program, each subject was re-evaluated to determine change in total, anterior-posterior, and medial-lateral single-limb stability. Two-way analysis of variance models were used to determine differences between pretraining and posttraining and between limbs.

RESULTS

The subjects showed a significant improvement in single-limb total stability (P = .004) and anterior-posterior stability (P = .001), but not medial-lateral stability (P = .650) for both the right and left lower extremity following training. In addition, the subjects demonstrated significantly better total postural stability on the right side as compared to the left (P = .026).

CONCLUSIONS

A 6-week neuromuscular training program designed to decrease the incidence of ACL injuries improves objective measures of total and anterior-posterior single-limb postural stability in high school female athletes.

Expression of transforming growth factor-beta (TGFbeta) and the TGFbeta signalling molecule SMAD-2P in spontaneous and instability-induced osteoarthritis: role in cartilage degradation, chondrogenesis and osteophyte formation

BACKGROUND

The primary feature of osteoarthritis is cartilage loss. In addition, osteophytes can frequently be observed. Transforming growth factor-beta (TGFbeta) has been suggested to be associated with protection against cartilage damage and new cartilage formation as seen in osteophytes.

OBJECTIVE

To study TGFbeta and TGFbeta signalling in experimental osteoarthritis to gain insight into the role of TGFbeta in cartilage degradation and osteophyte formation during osteoarthritis progression.

METHODS

Histological sections of murine knee joints were stained immunohistochemically for TGFbeta3 and phosphorylated SMAD-2 (SMAD-2P). Expression patterns were studied in two murine osteoarthritis models, representing spontaneous (STR/ort model) and instability-associated osteoarthritis (collagenase-induced instability model).

RESULTS

TGFbeta3 and SMAD-2P staining was increasingly reduced in cartilage during osteoarthritis progression in both models. Severely damaged cartilage was negative for TGFbeta3. In contrast, bone morphogenetic protein-2 (BMP-2) expression was increased. In chondrocyte clusters, preceding osteophyte formation, TGFbeta3 and SMAD-2P were strongly expressed. In early osteophytes, TGFbeta3 was found in the outer fibrous layer, in the peripheral chondroblasts and in the core. Late osteophytes expressed TGFbeta3 only in the fibrous layer. SMAD-2P was found throughout the osteophyte at all stages. In the late-stage osteophytes, BMP-2 was strongly expressed.

CONCLUSION

Data show that lack of TGFbeta3 is associated with cartilage damage, suggesting loss of the protective effect of TGFbeta3 during osteoarthritis progression. Additionally, our results indicate that TGFbeta3 is involved in early osteophyte development, whereas BMP might be involved in late osteophyte development.

Injury risk factors in female European football. A prospective study of 123 players during one season

The purpose of this study was to register prospectively the injuries in female soccer and to study their correlation to potential risk factors. A total of 123 senior players from eight teams of different levels were followed during one season. Isokinetic knee muscle strength at 60 and 180 degrees/s, one-leg-hop, vertical jump, square-hop, and continuous multistage fitness test (MFT) were tested at the end of the pre-season. In addition, Body Mass Index (BMI) and general joint laxity were measured. During the season, April-October, all injuries resulting in absence from one practice/game or more were registered. Forty-seven of the 123 players sustained altogether 65 injuries. The total injury rate was 14.3 per 1000 game hours and 3.7 per 1000 practice hours. The knee (26%) was the most commonly injured region followed by the foot (12%), ankle (11%), thigh (11%) and back (11%). The risk of sustaining moderate and major injuries increased in the later part of the game or practice. Significant risk factors for injuries were an increased general joint laxity (odds ratio (OR)=5.3, P<0.001), a high performance in the functional test square-hop (OR=4.3, P=0.002), and an age over 25 years (OR=3.7, P=0.01). The injury rate was not different compared to male soccer, but knee injuries were more common, which is in accordance with previous studies. None of the risk factors identified in this study is easily applicable for future intervention studies in the attempts to reduce the injury rate in female soccer.

Clinical, quantitative assessment of first tarsometatarsal mobility in the sagittal plane and its relation to hallux valgus deformity

Today, bunion surgery is still controversial. Considering that a bunion deformity in fact may be a result of multiple causes, the rationale of the currently applied techniques of surgical treatment has not been conclusively demonstrated. In view of the known hypermobility syndrome of the first ray that results in insufficient weightbearing beneath the first metatarsal head, the relationship between this syndrome and hallux valgus deformity has been investigated. The results suggest a direct relationship between painful hallux valgus deformity and hypermobility in extension of the first tarsometatarsal joint. A pathological mechanism of symptomatic hallux valgus is proposed that relates this pathology with primary weightbearing disturbances in the forefoot where angulation of the first metatarsophalangeal joint is one of the consequences. The alignment of the metatarsal heads within the sagittal plane seems to be a main concern in many hallux valgus deformities. As a consequence, treatment includes reestablishing stable sagittal alignment in addition to the horizontal reposition of the metatarsal over the sesamoid complex. As an example, first tarsometatarsal reorientation arthrodesis regulates the elasticity of the multiarticular first ray within the sagittal plane and may be the treatment of choice in many hallux valgus deformities.

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.

Trochleaplasty for recurrent patellar dislocation in association with trochlear dysplasia. A 4- to 14-year follow-up study

We investigated the clinical and radiological outcome of trochleaplasty for recurrent patellar dislocation in association with trochlear dysplasia in 38 consecutive patients (45 knees) with a mean follow-up of 8.3 years (4 to 14). None had recurrence of dislocation after trochleaplasty. Post-operatively, patellofemoral pain, present pre-operatively in only 35 knees, became worse in 15 (33.4%), remained unchanged in four (8.8%) and improved in 22 (49%). Four knees which had no pain pre-operatively (8.8%) continued to have no pain. A total of 33 knees were available for radiological assessment. Post-operatively, all but two knees (93.9%) had correction of trochlear dysplasia radiologically but degenerative changes of the patellofemoral joint developed in 30% (10) of the knees. We conclude that recurrent patellar dislocation associated with trochlear dysplasia can be treated successfully by trochleaplasty, but the impact on patellofemoral pain and the development of patellofemoral osteoarthritis is less predictable. Overall, subjective patient satisfaction with restored patellofemoral stability after trochleaplasty appeared to outweigh its possible sequelae.

Anterior knee pain after total knee arthroplasty: a narrative review

Anterior knee pain is one of the most common causes of persistent problems after implantation of a total knee replacement. It can occur in patients with or without patellar resurfacing. As a result of the surgical procedure itself many changes can occur which may affect the delicate interplay of the joint partners in the patello-femoral joint. Functional causes of anterior knee pain can be distinguished from mechanical causes. The functional causes concern disorders of inter- and intramuscular coordination, which can be attributed to preoperative osteoarthritis. Research about anterior knee pain has shown that not only the thigh muscles but also the hip and trunk stabilising muscles may be responsible for the development of a dynamic valgus malalignment. Dynamic valgus may be a causative factor for patellar maltracking. The mechanical causes of patello-femoral problems after knee replacement can be distinguished according to whether they increase instability in the joint, increase joint pressure or whether they affect the muscular lever arms. These causes include offset errors, oversizing, rotational errors of femoral or tibial component, instability, maltracking and chondrolysis, patella baja and aseptic loosening. In these cases, reoperation or revision is often necessary.

Is anterior knee pain a predisposing factor to patellofemoral osteoarthritis?

Adolescent anterior knee pain has traditionally been described as running a benign and self-limiting course. Studies more recently have questioned this supposition. This study aimed to assess how many patients who had undergone patellofemoral arthroplasty for isolated patellofemoral arthritis had previously suffered from adolescent anterior knee pain, knee instability and trauma. This group was then compared to a control group of medial unicompartmental arthroplasty patients. Both groups were surveyed by postal questionnaire, with a >75% response rate from each group. 22% of the patellofemoral arthroplasty group described adolescent or early adulthood anterior knee pain as compared to 6% in the medial unicompartmental arthroplasty group (p<0.001). Patients in the patellofemoral group had also suffered significantly more patellofemoral instability and trauma than the medial unicompartmental group (p<0.001 and p=0.02, respectively). A significant number of patients with patellofemoral arthritis have described preceding anterior knee pain in their adolescence and early adult years, raising the question as to whether anterior knee pain may be one of the contributing factors to patellofemoral osteoarthritis in later years.

Connective Tissue Disorders with Spontaneous Spinal Cerebrospinal Fluid Leaks and Intracranial Hypotension: A Prospective Study

OBJECTIVE

Intracranial hypotension attributable to a spontaneous spinal cerebrospinal fluid (CSF) leak is an increasingly recognized cause of postural headaches. The cause of these leaks is poorly understood, but it is likely multifactorial and may involve a primary connective tissue disorder. We undertook a study to estimate the contribution of systemic connective tissue disorders to the development of spontaneous spinal CSF leaks.

METHODS

We examined a group of 18 consecutive patients with spontaneous spinal CSF leaks for features of a connective tissue disorder.

RESULTS

The mean age of the 15 female patients and 3 male patients was 38 years (range, 22-55 yr). Seven patients (38%) demonstrated stigmata of a systemic connective tissue disorder, and three distinct types of disorders could be identified, as follows. 1) The association of spontaneous spinal CSF leaks and minor skeletal features of Marfan syndrome was noted for three patients. 2) Ehlers-Danlos syndrome Type II was noted for two patients. 3) Joint hypermobility associated with marked attenuation of the dorsal muscular fascia, precluding proper wound closure, was noted for two patients. In addition, isolated small-joint hypermobility was observed for five patients (28%). Slit-lamp ocular examinations, echocardiographic evaluations, histopathological examinations of skin biopsy specimens, and renal scanning did not reveal any other features of a systemic connective tissue disorder.

CONCLUSION

Findings suggesting connective tissue disorders are common among patients with spontaneous spinal CSF leaks, and manifestations may be subtle. A variety of disorders can be identified, probably reflecting genetic heterogeneity. Problems with wound healing may occur as a result of the systemic nature of the underlying connective tissue disorder.