Lateral release and medial plication for recurrent patella dislocation

Purpose

This study aims to report the long-term results of lateral release and medial plication in patients with recurrent patellar dislocation.

Methods

In this study, 31 patients who underwent surgery for recurrent patellar dislocation were retrospectively reviewed between 1994 and 2004. Among the 31 patients were 12 male and 19 female patients. The average age was 23.9?±?4.8?years, and the mean follow-up period was 11.6?±?2.4?years.

Results

Three patients had postoperative dislocations. The mean Kujala score significantly improved from 57.5?±?13.2 points preoperatively to 89.2?±?8.7 points at the final follow-up (P?<?0.0001). The median Tegner activity score significantly improved from 3 (range, 1?C5) at preoperative examination to 7 (range, 3?C9) at the final follow-up (P?<?0.0001). Ten patients were rated as excellent, 18 as good, 2 as fair, and 1 as poor. The congruence angle improved from 16.5°?±?3.0° to ?2.8°?±?2.7°, and the lateral patellofemoral angle improved from ?4.2°?±?1.9° to 8.2°?±?2.5°. There was no case of osteoarthritis at the final follow-up.

Conclusions

Percutaneous lateral release and medial plication showed satisfactory results with limited morbidity in the long-term follow-up. This traditional method remains a simple and effective surgical procedure for recurrent patellar dislocation.

Level of evidence

Therapeutic, Level IV.     

Kyphoplasty: indications, contraindications and technique

PURPOSE: Percutaneous Kyphoplasty is an emerging Interventional Radiology technique consisting in injecting polymethylmethacrylate (PMMA) into collapsed vertebral bodies under fluoroscopic guidance, after compaction of the cancellous bone with two dedicated balloon catheters. The purpose of our study was to assess the indications, contraindications, technique and results of our initial study. MATERIALS AND METHODS: Between January and May 2003 we treated 11 patients (5 men, 6 women) with vertebral collapse occurred up to three months earlier and due to osteoporosis or myeloma (mean age: 68.9), with pain refractory to medical therapy. All patients underwent treatment on a single vertebra (1 D7; 1 D8; 2 D12; 3 L1; 3 L2; 1 L4). Patient selection was based on clinical and instrumental criteria: conventional radiography, CT and MR were performed on all patients before the procedure. The Visual Analogue Scale (VAS) for pain assessment was used to evaluate the post-procedure results. RESULTS: All patients showed an increase in the height of the collapsed vertebral body, associated with partial or complete pain relief (VAS score decreasing from a pre-treatment score of 8 to a score of 2 after treatment). No complications related to the procedure were recorded. CONCLUSIONS: The indications for kyphoplasty include recent vertebral compression fractures due to osteoporosis, myeloma, metastasis and vertebral angioma with intractable pain and with no neurological symptoms. The main contraindications are coagulation disorders, unstable fractures or complete vertebral collapse (vertebra plana). Kyphoplasty proved to be a safe and effective method for the treatment of intractable pain due to vertebral collapse that allows for shorter hospital stays and an immediate improvement in the patient's quality of life.     

Percutaneous vertebroplasty: indications,contraindications, and technique

Percutaneous vertebroplasty is an emerging interventional technique in which surgical polymethylmethacrylate is injected via a large bore needle into a vertebral body under imaging guidance. This technique provides increased strength and pain relief in vertebrae weakened by a variety of bone diseases. The current indication for vertebroplasty is intractable non-radicular pain caused by compression fractures due to osteoporosis, myeloma, metastases and aggressive vertebral haemangioma. Contraindications include bleeding disorder, unstable fracture and lack of definable vertebral collapse. Our technique of percutaneous vertebroplasty is illustrated in this pictorial review.     

Percutaneous vertebroplasty: indications, contraindications, technique, and complications

Percutaneous vertebroplasty is emerging as one of the most promising new interventional procedures for relieving (or reducing) painful vertebra, with the injection of surgical polymethylmethacrylate or cement into vertebral bodies. This imaged-guided technique, originally used to treat vertebral hemangioma, has recently been extended to the treatment of metastases, osteoporotic compression fractures, and vertebral myeloma. It is increasingly being accepted as a main treatment of choice in the management of resistant back pain due to vertebral compression fractures, especially in the elderly individual who is not a candidate for surgery. In this article, we review indications, contraindications, technique, and complications of percutaneous vertebroplasty.     

Lateral unicompartimental knee arthroplasty: indications,technique and short-medium term results

Lateral unicompartmental knee arthroplasty (UKA) is a valid alternative treatment in the event of arthritis confined to the lateral compartment. This paper examines its indications, technique and short to medium-term results. A total of 159 Miller–Galante cemented UKA prostheses (Zimmer, Warsaw, Indiana) were implanted consecutively (131 medial and 28 lateral) by the same surgeon. This study investigates 28 lateral UKAs in 27 patients. Twenty-five implants in 24 patients (including a subject operated bilaterally) were followed up for 12–60 months. Three patients were discarded on account of to short a follow-up period. The Hospital for Special Surgery (HSS) knee score was used to compare the pre- and post-operative results of the lateral UKA patients. The HSS score improved from a pre-op mean of 59.92 (range 48–68) to 88.04 (range 71–95) at the last follow-up. There was a positive increase in the pain, function and ROM components of the score. The lateral UKA prosthesis can be regarded as a sound alternative to total knee replacement. Correct patient selection on the basis of optimum surgical indications, however, is essential. No benefits of funds were received in support of the study.     

Quantitative stress radiography of the patella and evaluation of patellar laxity before and after lateral release for recurrent dislocation patella

Purpose

The aims of the present controlled clinical study were to (1) compare patella laxity determined in the outpatient clinic with that in anaesthetized patients and (2) evaluate patella laxity before and after lateral release.

Method

The study evaluated data on 33 knees from 33 patients (average age 19.7 years) between 2007 and 2011. All patients were diagnosed with recurrent dislocation of the patella. Patellar stability was evaluated in each patient thrice: patellas were first imaged in the outpatient clinic prior to surgery at 45° knee flexion with 20 N stress from the medial to lateral side and from the lateral to medial side; then, at the time of surgery, patella stress images were obtained in the same manner before and after the lateral release procedure. Radiological assessments were performed using the medial stress shift ratio (MSSR) and lateral stress shift ratio (LSSR).

Results

There were no significant differences in the LSSR and MSSR before surgery (outpatient data) and in anaesthetized patients before the lateral release procedure. Furthermore, there was no significant difference in MSSR at the time of surgery before and after the lateral release procedure. However, LSSR increased significantly after the lateral release procedure.

Conclusion

The results of the present study suggest that quantitative patella stress radiography in the outpatient clinic is useful when it comes to investigating laxity of the patella, and that lateral release significantly increases lateral, but not medial, laxity in patients with recurrent patellar dislocation.

Level of evidence

IV.     

Effects of lateral retinacular release on the lateral stability of the patella

The objective of this cadaveric study was to evaluate quantitatively the effects of lateral retinacular release on the lateral stability of the patella. A materials testing machine was used to displace the patella of seven cadaveric specimens 10 mm laterally while measuring the required force, with 175 N quadriceps tension. The patella was connected via a ball-bearing patellar mounting 10 mm deep to the anterior surface to allow rotations. Patellar force--displacement behaviour was tested from 0° to 60° knee flexion. At 0°, 10° and 20° flexion the mean force required to displace the patella 10 mm laterally was reduced significantly due to lateral retinacular release, by 16–19%. The average force required to displace the patella was also reduced for larger flexion angles, although this was not statistically significant. These findings suggest that lateral retinacular release may not be appropriate in treatment of patellar lateral instability.     

Results of arthroscopic medial retinacular release for treatment of medial subluxation of the patella

BACKGROUND: Medial subluxation of the patella is a rare, disabling condition that has iatrogenic and traumatic causation. To date, only open reconstructions have been reported for operative treatment of this condition, but these procedures have a high rate of complications, revisions, and subsequent surgery. This is the first study to present the results of arthroscopic medial retinacular release for treatment of this problem. HYPOTHESIS: Arthroscopic release will alleviate painful medial patellar subluxation. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Nine knees (7 patients) with painful, recurrent medial subluxation of the patella that occurred spontaneously (2 knees) or after a lateral release (5 knees) or an injury (2 knees) were treated with an arthroscopic medial retinacular release. The retinaculum was released 2 cm medial to the superior pole of the patella down to the anteromedial portal. At a mean follow-up of 2.7 years (range, 1-8 years), all knees were evaluated, and the results were graded according to the Merchant and Mercer rating scale. RESULTS: The mean age of the patients was 25 years (range, 15-38 years), and the mean duration of the subluxations before surgery was 28 months (range, 6-48 months). In all 7 patients (9 knees), the medial release relieved their medial subluxation and knee pain, and there were 6 excellent and 3 good results. There were no complications or further realignment surgery needed after this procedure. CONCLUSION: An arthroscopic medial retinacular release will successfully treat painful medial subluxation of the patella.     

Dorsal defect of the patella: concept of its origin and relationship with bipartite and multipartite patella

In a series of 2286 single radiographic examinations of the knee in 1985, 6 dorsal defects of the patella (DDP) were detected. The diagnosis was made if a round lucent lesion of the dorsal superolateral surface of the patella [9] was found abutting against articular cartilage [10]. In four of our patients, an association with a multipartite patella (MP) was found. Biopsy of one lesion showed dense connective tissue and areas of bone necrosis. In one patient, the pattern of reossification of the lesion could be demonstrated. Our observations provide further evidence that the DDP is a stressinduced anomaly of ossification rather than a posttraumatic subarticular cyst of the patella, a diagnosis sometimes suggested by the clinical context. The initial lesion is probably a traction lesion at the insertion of the vastus lateralis muscle rather than ulceration of articular cartilage. We suggest a possible relationship between dysfunction of the quadriceps mechanism, patellar subluxation, and the genesis of the DDP.     

Dorsal effect of the patella: incidence and distribution

To determine the incidence and distribution of dorsal defect of the patella, the radiographs of 2,349 knees in 1,192 consecutive patients were evaluated. The defect was present in about 1% of the population. It may be found at any age from the preadolescent to the mature adult. Females were more commonly affected than males. The test population group was validated by concurrent tabulation and comparison with other series of two other bening lesions occurring at the knee: fabella and multipartite patella.     

Biologic resurfacing of the patella: current status

The techniques of biologic resurfacing of the patella, like other joint surfaces, are still evolving. Currently none of them is free from criticism. In this regard it is our hope that progress in the basic science will offer in the near future new and more optimistic therapeutic possibilities (i.e., the restoration of a reparative cartilage that is structurally and functionally comparable to the native one). The greater expectancies come perhaps from the present experimental investigations about the combined use of tissue-engineered implants embedded with staminal cells and growth factors. Many problems remain to be solved, however, before reliable applicability in humans. From a general point of view, stem cells obtained from various sources (e.g., adult bone marrow, umbilical cord) offer the same finalities as the embryonic stem cells, without the ethical obstacles related to the latter. Therefore, it may be that restoration of part or all of the articular surface of a joint will be possible by way of these mesenchymal progenitors that have the ability to differentiate into the chondrogenic and osteogenic lines, which is required for the restoration of the various layers of a normal articular cartilage and subchondral bone.     

Tuberculosis of the patella

 A rare case of tuberculosis of the patella is presented. Diagnostic features include an osteolytic lesion in the patella with flaky sequestrum, associated with typical clinical features. Treatment should be urgent and should include a regimen of surgical debridement along with four antitubercular drugs. Once the joint is involved, the end results become less satisfactory.     

Dorsal defect of the patella: MR features

Dorsal defect of the patella (DDP) is a benign lesion with characteristic radiologic features. We describe the MR appearance of a typical DDP and a healed DDP as seen in two patients. The classic CT appearance is also described.     

Osteonecrosis of the patella: imaging features.

Osteonecrosis of the patella, although uncommon, has become important to recognize because it can be a cause of pain in the knee. We describe the imaging manifestations of nontraumatic osteonecrosis of the patella in seven clinical cases. The lesions uniformly involved the superior aspect of the patella. Conventional radiography displayed increased radiodensity, subchondral radiolucent areas, and typical demarcation line surrounding the ischemic region. MR imaging and bone scintigraphy demonstrated the characteristic features of osteonecrosis. Recognition of the imaging findings of osteonecrosis involving the patella can preclude misdiagnosis and may obviate unproductive invasive diagnostic procedures.     

Chondroblastoma of the patella

This study reviews 16 cases of chondroblastoma of the patella which constitute nearly 6% of a large group of chondroblastomas scattered throughout the skeleton. Both radiologic and histologic appearances of chondroblastomas of the patella are indistinguishable from those of chondroblastomas arising in other sites. A reasonable differential diagnosis, including chondromalacia patella, is discussed together with important therapeutic considerations.