[Vertical intrapatellar restraint in patellar dislocation, patellar tissue insufficiency and patellar chondropathy (author's transl)].
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Adult↗
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Results for “Patellar Dislocation”
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Patellar dislocation: arthroscopic patellar stabilization with anchor sutures.
There are many procedures to treat recurrent patellar subluxations and dislocations. Most of these procedures are open repairs for acute conditions or open reconstructions for chronic conditions, and both surgeries need large skin incisions. Although there are many arthroscopic procedures for meniscal and ligament injuries, there are very few arthroscopic procedures described for patellofemoral instability. In this report, we describe a new arthroscopic method to stabilize the patella for acute dislocation. Our technique includes an arthroscopic lateral release and a medial structure repair. We suggest that this procedure is minimally invasive and easier than traditional open procedures. Moreover, this may prevent patients from developing chronic instability of the patellofemoral joint.
Acute Disease↗
Locked lateral patellar dislocation: a rare case of irreducible patellar dislocation requiring open reduction.
Irreducible patellar dislocations are rare injuries, but those that do occur are mainly directed intra-articularly. In this case, a 53-year-old woman sustained a locked lateral patellar dislocation when falling from a chair. A preoperative CT-scan revealed bony avulsions at the insertion of the vastus medialis muscle, the medical retinaculum, and partial disruption of the ligamentum patellae from the apex patellae. Open reduction was necessary and the torn structures were reattached with anchor systems and sutures. Postoperative management included intensive physiotherapy. At 1 year after surgery, the patient was without swelling or pain and had a normal gait, but flexion was restricted to 120 degrees. All postoperative radiographs showed the patella correctly placed in the femoral groove.
Accidental Falls↗
A long-term follow-up study after medial patellofemoral ligament reconstruction using the transferred semitendinosus tendon for patellar dislocation.
The management of patellar dislocation syndrome has traditionally been difficult. There are no golden standard methods for patellar dislocations probably due to the many etiologies. However, it is known that medial patellofemoral ligament (MPFL) is damaged when the patella is dislocated. The purpose of this study is to examine whether our method of MPFL reconstruction is useful for the treatment of dislocated patellae and unstable patellae. Forty-six knees (43 patients) of 68 knees (65 patients) that were operated on using our surgical procedure for MPFL reconstruction with the advancement of the vastus medialis or the MPFL reconstruction with Insall's procedure were followed up for at least 5 years. The patient age ranged from 6 to 43 years. These knees consisted of six habitual dislocation patellae, twenty-six recurrent dislocation patellae, ten traumatic dislocation patellae, and four unstable patellae. The patients were evaluated pre-operatively and more than three times post-operatively at 6, 12, 36, 60, or 120 months. No patient experienced patellar dislocation after surgery. Their post-operative Kujala's scores were significantly improved. On conventional X-ray and on stress X-ray evaluations, the mean values for congruence angle, tilting angle, lateral shift ratio, medial stress shift ratio, and lateral stress shift ratio at the final follow-up (60 or 120 months) were demonstrated to be within the normal range. We conclude that our MPFL reconstruction method with the advancement of the vastus medialis or with Insall's procedure might be recommended for the treatment of habitual, recurrent, and indeed any other type of patellar dislocation, as well as for unstable patellae.
Adolescent↗
Cartilage lesions of the patella in recurrent patellar dislocation.
BACKGROUND: The etiology of patellar cartilage lesions in recurrent patellar dislocation has been poorly understood. HYPOTHESIS: The pathology of cartilage lesions of the patella accompanied by recurrent patellar dislocation can be analyzed. STUDY DESIGN: Series of case reports. METHODS: In 70 knees from 57 patients with recurrent patellar dislocation, the cartilage lesions of the patella were examined using arthroscopy and/or macroscopic observation. The average age of the patients was 22 years (range, 13 to 40 years). Lesions that involved only softening were not included. RESULTS: Sixty-seven knees (96%) had articular cartilage lesions of the patella, and only 3 knees had no change. Fissuring was observed in 53 knees (76%). The most common site of fissuring was on the central dome. There were basically two types of fissuring: multiple longitudinal fissuring and marginal/radial fissuring. Fibrillation and/or erosion were observed in 54 knees (77%). Of these, 40 knees had fissuring and 14 did not have fissuring. The main site of fibrillation and/or erosion was the medial facet. CONCLUSIONS: Cartilage lesions of the patella in recurrent patellar dislocation cases were very common. Fissuring was observed mainly on the central dome, and fibrillation and/or erosion were observed mainly on the medial facet.
Adolescent↗
[Old unreduced traumatic patellar dislocation].
The old unreduced traumatic patellar dislocation is very rare and the results of the treatment are not always satisfactory. We report a 11 year-old boy with an unreduced patellar dislocation and a healed ipsilateral femoral fracture. The dislocation was reduced by an operative procedure. A long leg cast was applied for 6 weeks then the knee exercises were started. One year after surgery, he still has satisfactory results. This case suggests that if the dislocation is not of long duration and degenerative changes are absent in the patella and the knee joint, open reduction may be helpful in the treatment of old unreduced traumatic patellar dislocations. .
Child↗
MR imaging of patellar dislocation and relocation.
Patellar dislocation and relocation (PDR) typically occurs suddenly after trauma or torsional stress on the extensor mechanism. Clinical evaluation after patellar dislocation/relocation usually reveals a swollen knee that is difficult to examine. Radiographs may show hemathroses and a minority of patients will have a chip fracture of the patella. Magnetic resonance (MR) imaging features seen with PDR include disruption or sprain of the medial retinaculum, lateral patellar tilt or subluxation, lateral femoral condylar and medical patellar osseous contusions, osteochondral injury, damage to Hoffa's fat pad, and joint effusion. Up to one third of patients will also show concomitant injury to the major ligaments of the knee or menisci. Without repair of the primary injury, redislocation occurs in greater than one half of patients. Consequently, surgical correction is often advocated. This article reviews the factors predisposing to PDR, the activities associated with PDR, the clinical, radiographic, and MR imaging features of PDR, and (briefly) therapy for this injury.
Humans↗
[Biomechanics and semiology of transient lateral patellar dislocation: reliability of magnetic resonance diagnosis].
Transient patellar dislocation is a rare finding. It is usually due to direct trauma in mediolateral direction or to indirect trauma related to violent quadriceps muscle contraction. The clinical diagnosis of transient forms is usually rather difficult because the associated signs (hemarthros and pain at the joint and/or at the vastus medialis insertion) are not specific. Conventional radiography and CT are very accurate in bone studies, but exhibit major limitations in the detection of capsular injuries with intramedullary and/or cartilaginous bone involvement. We investigated MR diagnostic reliability in the study of the injuries caused by transient patellar dislocation. 526 MR examinations of the knee were reviewed retrospectively; fifteen of them were positive for transient patellar dislocation. We used a .5 T superconductive MR unit with a circumferential extremity coil. Axial, coronal and sagittal T1-weighted spin echo, T2*-weighted gradient echo and axial STIR images were acquired. The following criteria were considered specific for the diagnosis of former lateral patellar dislocation: retinacular changes; patella site; signal intensity changes in femoral and patellar intramedullary bone; joint effusion; cartilage and subchondral bone changes. All the patients with transient patellar dislocation had hemarthros with inner retinaculum involvement. The femoropatellar joint was incongruous in 115 cases; patellar subluxation was external in 8/11 patients and lateral in the remaining 3 patients. Medullary bruises were found in 8/15 cases and cartilage injuries in 13/15. Finally, other joint components, such as the posterior horn of the medial meniscus or the anterior cruciate ligament were involved in 6/13 cases. Arthroscopy was performed in 6 patients with associated injuries and confirmed all MR findings (100% agreement). To conclude, in our experience MRI was a very reliable tool to study the injuries due to transient patellar dislocation because it showed specific changes and possible associated traumas, which helps choose the most suitable treatment.
Adolescent↗
Patellar dislocation after total knee arthroplasty.
BACKGROUND: Patellar problem is an important cause of nonseptic failure of the current condylar design of total knee arthroplasties. Patellar dislocation after total knee arthroplasty is infrequent but can cause disabling symptoms. METHODS: From March, '84 to July, '92, 1652 total knee arthroplasties were performed at this Hospital. Of these 1100 knees in 978 patients were available to be followed up regularly at the Outpatient Department. Eleven cases of patellar dislocation after total knee arthroplasty were encountered during follow-up. Among these patients, nine patients had received operation at this Hospital; the other two patients had been referred here by the other hospitals. All 11 patients had been treated with surgical methods: proximal realignment of the quadriceps alone in 6 knees, lateral retinacular release combined with revision of the malaligned components in 2 knees, combined proximal and distal realignment in 2 knees and patellar tendon transfer in 1 knee. RESULTS: After an average follow-up of 21.8 months, from April, '84 to April, '93, there was one redislocation, unfortunately caused by trauma. Using the average knee rating scale of the Hospital for Special Surgery, New York, USA, the results of 90.5 were satisfactory and encouraging. CONCLUSIONS: Patellar dislocation after total knee arthroplasty can cause disabling symptoms, including pain, weakness, limited range of motion, extension lag and difficulty when climbing up or down stairs. The cause of patellar dislocation after total knee arthroplasty was error in surgical technique in this series. Revision of the component should be performed in those with malaligned component. Proximal realignment is recommended in those with quadriceps imbalance. Distal realignment is recommended only when proximal realignment alone has failed to restore proper patellar tracking, this should be carried out with great caution due to the potential for serious complications.
Aged↗
Transient lateral patellar dislocation: diagnosis with MR imaging.
OBJECTIVE: Transient lateral patellar dislocation is frequently difficult to diagnose accurately on the basis of clinical findings. Accordingly, we studied the MR findings in 26 cases to determine if MR imaging is useful in establishing the diagnosis. MATERIALS AND METHODS: A retrospective review of 1450 MR examinations of acutely injured knees was performed to determine the MR findings resulting from transient lateral patellar dislocation. A distinctive constellation of MR findings reflecting the known mechanism of injury indicative of transient lateral patellar dislocation was found in 26 patients. Patellar dislocation was not clinically suspected before imaging in 19 (73%) of these 26 patients; most patients had been referred for suspected injury of the cruciate ligaments or menisci. Axial, sagittal, and coronal MR images were obtained in all patients, and all had clinical follow-up. Correlation of MR findings with surgical findings was possible in six. RESULTS: Specific components of the constellation of MR findings included disruption or sprain of the medial retinaculum in 25 (96%) of 26 patients, lateral patellar tilt or subluxation in 24 patients (92%), lateral femoral condyle contusion in 21 patients (81%), osteochondral injury in 15 patients (58%), and joint effusion in all 26 patients (100%). Concomitant injury to major ligaments or menisci was present in eight (31%). CONCLUSION: Our findings suggest that patients with transient lateral patellar subluxation have a distinctive constellation of MR findings that can be used to distinguish this entity from other common knee injuries.
Adolescent↗
Patellar tendonitis and patellar dislocations.
Common sports injuries, such as patellar tendonitis and patellar dislocation, can be treated either surgically or with rehabilitation and physical therapy. Most patients with patellar tendonitis will respond well to conservative measures; however, some recalcitrant cases will require surgical intervention. To date, the literature is not able objectively to identify the patients best suited to surgery. Likewise, in the case of patellar dislocations, it is still unclear which patients respond best to conservative therapy and which respond best to surgical treatment, although evidence continues to accumulate. A practical approach to this problem can be deduced from the available evidence, but more well-designed clinical trials are needed for the establishment of definitive treatment protocols.
Athletic Injuries↗
[Interim results of surgical therapy of patellar dislocation by Insall proximal reconstruction].
Between 1984 and 1991, 57 patients with diagnosis of an acute or recurrent patellar dislocation were treated operatively using proximal realignment with vastus medialis transfer and lateral release (Insall operation). A total of 45 patients (15 with acute and 30 with recurrent patellar dislocation) were reviewed at an average follow-up of 6.5 years (2-9.6 years). The average age at injury was 21.5 years, with a predominance of female patients. Follow-up examination included routine knee examination, clinical review using the modified knee scoring scale of Larsen and Lauridsen, sports activity level and subjective satisfaction. Radiographics from 27 patients (60%) were evaluated. One patient from each group suffered recurrence of patellar dislocation. All patients had stable knee joints and a full range of motion. There was no statistical difference in the pre- and postoperative sports activity level in both groups. Three patients (19.9%) with acute patellar dislocation and seven patients (23.3%) with recurrent patella dislocation had excellent results using the Larsen and Lauridsen score scale. Ten patients (66.6%) with acute and 12 (39.9%) with recurrent dislocation had good results. One patient with recurrent patellar dislocation had a fair result. Subjective evaluation revealed the operative result in 93% of cases as very good, good or satisfactory. Patellofemoral osteoarthritis was seen in 11 (40.7%) of 27 patients. Our results show good clinical results for the treatment of acute patellar dislocation in young, active patients with the proximal realignment procedure. The recurrence rate of patellar dislocation can be reduced for acute and recurrent patellar dislocation. Subjective satisfaction with this procedure is rated very good.
Acute Disease↗
The reliability and validity of knee-specific and general health instruments in assessing acute patellar dislocation outcomes.
BACKGROUND: The most reliable and valid instruments for assessing patient outcome after patellar dislocation have not been identified. HYPOTHESIS: Knee-specific and general health instruments will differ in validity and reliability for patients with patellar dislocation. STUDY DESIGN: Prospective cohort study. METHODS: Subjects consisted of 153 patients with acute patellar dislocation (110 with first-time dislocations and 43 with a history of patellofemoral subluxation or dislocation). We administered the modified International Knee Documentation Committee form, Kujala, Fulkerson, Lysholm, Tegner, Short Form 36, and Musculoskeletal Function Assessment instruments on two separate occasions (test-retest reliability). Validity was assessed by comparing scores of the two groups and by comparing scores of patients with and without recurrent subluxations/dislocations during follow-up. RESULTS: The knee-specific instruments yielded the highest test-retest reliability. The knee-specific and general health instruments identified higher disability levels in the patients with a history of patellofemoral problems than in those with first-time dislocations. The general health instruments identified higher disability levels in patients with patellar dislocation than published norms. The Fulkerson and Lysholm scales were the only instruments to differentiate between patients with and without recurrent subluxations/dislocations. CONCLUSIONS: Knee-specific scales yielded higher reliability coefficients and stronger validity than did general health instruments. Knee-specific, general health, and activity level instruments are complementary and in combination provide a more complete assessment for patients with patellar dislocation.
Adolescent↗
Generalized joint laxity and contralateral patellar hypermobility in unilateral recurrent patellar dislocators.
PURPOSE: The purpose of this study was to assess the relation between generalized joint laxity and patellar hypermobility in unilateral recurrent patellar dislocators. TYPE OF STUDY: Case series. METHODS: A total of 82 patients (23 male and 59 female patients) with unilateral recurrent patellar dislocation were studied compared with an age- and sex-matched control group. The modified Carter and Wilkinson criteria for generalized joint laxity and lateral patellar hypermobility test were examined. RESULTS: Generalized joint laxity (score of 4 or 5) was present in 20 patients (24%) with recurrent patellar dislocation in 8 subjects (10%) of the control group. The mean total score was 2.5 (SD, 1.4) in the recurrent patellar dislocators and 1.7 (SD, 1.3) in the control group. The incidence of generalized joint laxity (P = .013) and the mean total score (P = .00004) were statistically significant between the two groups. A hypermobile patella was present in 42 patients (51%) and in 5 subjects (6%) of the control group. There was a large statistically significant difference between the two groups (P < .00001). CONCLUSIONS: Although a hypermobile patella and generalized joint laxity were significant between the recurrent patellar dislocators and the control group, a hypermobile patella was more significant than generalized joint laxity as the predisposing factors of patellar dislocation. LEVEL OF EVIDENCE: Level IV, prognostic case series.
Adolescent↗
Second-look arthroscopy of cartilage changes of the patellofemoral joint, especially the patella, following acute and recurrent patellar dislocation.
OBJECTIVE: The purpose of this study was to clarify some pathogenesis of the cartilage changes of the patellofemoral joint in patellar dislocation knees. METHODS: A first arthroscopy was performed in a total of 60 knees, including 30 knees of acute patellar dislocation (APD) and 30 knees of recurrent patellar dislocation (RPD). At the time of the first arthroscopy, 58 knees sustained open medial patellofemoral ligament repair/reconstruction, and 2 knees had only arthroscopy examination. In APD knees, the second-look arthroscopy was performed 16.7 months after the first arthroscopy, and in RPD knees, 25.2 months after the first arthroscopy. RESULTS: In most APD knees, cracking primarily on the central dome of the patella did not have a remarkable change but in several knees that had a high number of cracking or interlaced cracking, cracking became worse with fibrillation. Osteochondral defect site primarily on the medial facet showed fibrillation and/or ulceration (erosion). In most RPD knees, fissuring primarily on the central dome did not have a remarkable change, and fibrillation and/or erosion mainly on the medial facet also did not have a remarkable change. However, in four knees with the continuation of patellar dislocation, the patellar cartilage changes had definitely worsened. On the other hand, in the first and second-look arthroscopy, most APD and RPD knees had no remarkable cartilage lesions or cartilage changes of the femoro-trochlear aspect. CONCLUSIONS: One of the pathogenesis of fissuring in RPD knees seems to be cracking occurring at the time of APD. Two of the pathogenesis of fibrillation may result from the reparative reaction of the cartilage in osteochondral defect site and the cartilage change due to a high degree of cracking damage mainly on the central dome in APD injury. The continuation of patellar dislocation definitely makes the patellar cartilage lesions worse.
Acute Disease↗
Articular cartilage injury with acute patellar dislocation in adolescents. Arthroscopic and radiographic correlation.
Acute patellar dislocation and relocation produces major forces at the articular surfaces. Articular injury was assessed in 48 patients, 24 boys and 24 girls (mean age, 14 years), with acute, initial, noncontact patellar dislocations. Correlation of the findings of radiographic and arthroscopic examinations was done. Eleven of the 48 patients (23%) had radiologic diagnoses of articular injuries. Thirty-four of the 48 patients (71%) had arthroscopic evidence of articular damage, 32 osteochondral and 2 chondral injuries. Eight of the 28 (29%) arthroscopically identified osteochondral loose bodies (4 to 20 mm) were identified radiologically. Overall, only 11 of the 34 (32%) arthroscopically documented articular injuries were defined by preoperative radiographs. These standard radiographs provided limited information for management decisions. Poor results after patellar dislocation treatment may involve nonrecognition of articular compromise.
Acute Disease↗
Classification of lesions of the medial patello-femoral ligament in patellar dislocation.
The remnants of the medial patello-femoral ligament (MPFL) of 67 knees, 18 with acute patellar dislocation and 49 with chronic patellar dislocation, were studied. The MPFL injuries of the acute cases were categorised into 2 groups: an avulsion tear type and a substantial tear type. The chronic cases were put into 3 groups: those with loose femoral attachment (9 knees), those with scar tissue formation or abnormal scar branch formation (29 knees), and those with no evidence or continuity of the ligament (absent type) (11 knees). It is concluded that incompetence of the medial patello-femoral ligament is a major factor in the occurrence of recurrent patellar dislocation and/or an unstable patella following an acute patellar dislocation.
Acute Disease↗
Mini-open medial reefing and arthroscopic lateral release for the treatment of recurrent patellar dislocation: a medium-term follow-up.
BACKGROUND: Although recurrent patellar dislocations are not uncommon, their pathophysiology and treatment are controversial. HYPOTHESIS: Stabilization of recurrent patellar dislocations can be successfully managed with a mini-open approach. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-two patients (23 knees) underwent a mini-open medial reefing and arthroscopic lateral release for the treatment of recurrent patellar dislocations with an average follow-up of 4.4 years (range, 1.4-14 years). The average age at the first dislocation was 15 years (range, 5-26 years), and the average age at surgery was 23 years (range, 12-65 years). RESULTS: There was 1 postoperative dislocation (4%) and 1 recurrent subluxation (4%). The average Kujala knee score was 88.2 +/- 13.5, with overall good scores in each category. The lowest scores involved squatting (5.7), abnormal painful kneecap movements (subluxations) (7.1), and jumping (7.9). Overall, there was a statistically significant improvement in the Tegner score from 3.7 +/- 1.8 before surgery to 6.9 +/- 2.0 after surgery (P < .001). Six knees (26%) were rated subjectively as excellent, 15 (65%) as good, 2 (9%) as fair, and 0 (0%) as poor. All 22 patients (100%) stated that the procedure was worthwhile. Radiographically, there was a statistically significant improvement in the congruence angle (normal, -8.0 degrees +/- 6.0 degrees) from 15.7 degrees +/- 12.6 degrees (range, 0.0 degrees to +44.0 degrees) before surgery to -11.5 degrees +/- 8.7 degrees (range, -20.0 degrees to +10.0 degrees) after surgery (P < .001) and in the lateral patellofemoral angle (normal, >0 degrees) from -0.2 degrees +/- 6.4 degrees (range, -10 degrees to +8 degrees) before surgery to 7.9 degrees +/- 2.6 degrees (range, 0.0 degrees to +11.0 degrees) after surgery (P < .001). CONCLUSION: Our mini-open technique provides anatomical restoration with limited morbidity and cosmetically appealing results. Furthermore, our redislocation rates compare favorably with traditional, more extensile open approaches.
Adolescent↗