Conservative versus tailored surgical treatment in patients with first time lateral patella dislocation: a randomized-controlled trial.

BACKGROUND: Patellar instability has a high incidence and occurs particularly in young and female patients. If the patella dislocates for the first time, treatment is usually conservative. However, this cautious approach carries the risk of recurrence and of secondary pathologies such as osteochondral fractures. Moreover, there is also risk of continuous symptoms apparent, as recurrent patella dislocation is related to patellofemoral osteoarthritis as well. An initial surgical treatment could possibly avoid these consequences of recurrent patella dislocation. METHODS: A prospective, randomized-controlled trial design is applied. Patients with unilateral first-time patella dislocation will be considered for participation. Study participants will be randomized to either conservative treatment or to a tailored patella stabilizing treatment. In the conservative group, patients will use a knee brace and will be prescribed outpatient physical therapy. The surgical treatment will be performed in a tailored manner, addressing the pathologic anatomy that predisposes to patella dislocation. The Banff Patellofemoral Instability-Instrument 2.0, recurrence rate, apprehension test, joint degeneration, and the Patella Instability Severity Score will serve as outcome parameters. The main analysis will focus on the difference in change of the scores between the two groups within a 2-year follow-up. Statistical analysis will use linear mixed models. Power analysis was done for the comparison of the two study arms at 2-year follow-up with regard to the BPII Score. A sample size of N = 64 per study arm (128 overall) provides 80% power (alpha = 0.05, two-tailed) to detect a difference of 0.5 standard deviations in a t-test for independent samples. DISCUSSION: Although several studies have already dealt with this issue, there is still no consensus on the ideal treatment concept for primary patellar dislocation. Moreover, most of these studies show a unified surgical group, which means that all patients were treated with the same surgical procedure. This is regarded as a major limitation as surgical treatment of patella dislocation should depend on the patient's anatomic pathologies leading to patellar instability. To our knowledge, this is the first study investigating whether patients with primary patella dislocation are better treated conservatively or operatively with tailored surgery to stabilize the patella. TRIAL REGISTRATION: The study will be prospectively registered in the publicly accessible database www.ClinicalTrials.gov .

[Rare cause of knee pain after total knee arthroplasty]. / Seltene Knieschmerzursache nach Knietotalendoprothesenimplantation.

A painful knee after total knee arthroplasty may have various causes. In addition to commonly occurring causes, such as infections, aseptic loosening, implant failure or typical anterior knee pain, rare causes also have to be taken into account. We report a previously unknown cause of knee pain after total knee replacement involving a non-resected medial meniscus, which was sandwiched between the medial condyle of the femur and the inlay of the prosthesis and caused pain typical for a medial meniscus. After arthroscopic meniscectomy the patient was symptom-free.

Preoperative pregabalin administration significantly reduces postoperative opioid consumption and mechanical hyperalgesia after transperitoneal nephrectomy.

BACKGROUND: Preoperative administration of pregabalin is proposed as a promising way of enhancing postoperative pain control. Whereas a few studies have investigated the effect of pregabalin on postoperative opioid consumption, no study has focused on the influence on postoperative hyperalgesia. In this randomized, triple-blinded, placebo-controlled study, we aimed to demonstrate that a single, preoperative dose of pregabalin reduces postoperative opioid consumption, mechanical hyperalgesia, and pain sensitivity. METHODS: Patients undergoing elective transperitoneal nephrectomy received 300 mg pregabalin or placebo 1 h before anaesthesia. After operation, patients received piritramide via a patient-controlled analgesia device. Pain levels and side-effects were documented. The area of hyperalgesia for punctuate mechanical stimuli around the incision was measured 48 h after the operation with a hand-held von Frey filament. Mechanical pain threshold was tested before and 48 h after surgery with von Frey filaments with increasing diameters. RESULTS: In each group, 13 patients were recruited. Total piritramide consumption [77 (16) vs 52 (16) mg, P=0.0004] and the normalized area of hyperalgesia [143 (87) vs 84 (54) cm(2), P=0.0497] were significantly decreased in the pregabalin group. There were no significant differences in mechanical pain threshold levels [1.20 (0.56) log(g) vs 1.05 (0.58) log(g), P=0.6738]. No case of severe sedation was reported in both groups. No other side-effects were observed. CONCLUSIONS: Our study has shown that preoperative administration of 300 mg pregabalin in patients undergoing transperitoneal nephrectomy reduces postoperative opioid consumption and decreases the area of mechanical hyperalgesia.

The painful knee after TKA: a diagnostic algorithm for failure analysis.

Pain after total knee arthroplasty (TKA) represents a common observation in about 20% of the patients after surgery. Some of these painful knees require early revision surgery within 5 years. Obvious causes of failure might be identified with clinical examinations and standard radiographs only, whereas the unexplained painful TKA still remains a challenge for the surgeon. It is generally accepted that a clear understanding of the failure mechanism in each case is required prior considering revision surgery. A practical 10-step diagnostic algorithm is described for failure analysis in more detail. The evaluation of a painful TKA includes an extended history, analysis of the type of pain, psychological exploration, thorough clinical examination including spine, hip and ankle, laboratory tests, joint aspiration and test infiltration, radiographic analysis and special imaging techniques. It is also important to enquire about the length and type of conservative therapy. Using this diagnostic algorithm, a sufficient failure analysis is possible in almost all patients with painful TKA.

[The painful patellofemoral joint. Biomechanics, diagnosis and therapy]. / Das schmerzhafte Patellofemoralgelenk : Biomechanik, Diagnostik und Therapie.

New knowledge about the pathophysiology and biomechanics of the patellofemoral joint (PFJ) has led to a better understanding and new treatment options. To recognise the main pathology is the most important and difficult part. This article describes the basic principles of biomechanics (static, passive and active factors) and their influence on the PFJ. Patients are classified into three groups (pain, instability and arthritis). This is achieved by a clinical evaluation and standard X-rays. The instability group is analysed additionally with MRI. The aim of this evaluation is to analyse the biomechanical cause of the instability. Based on a pathophysiological concept a new therapeutic algorithm is introduced.

Lamotrigine monotherapy for control of neuralgia after nerve section.

BACKGROUND: We present six patients treated only with the new-generation anticonvulsant lamotrigine to define its sole effect on neuralgia after nerve section. METHODS: Previous surgical or pharmacological attempts failed to relieve this neuropathic pain in our patients. Before initiation of lamotrigine therapy, patients reported spontaneous and touch-evoked shooting pain followed by periods of burning pain. No breakthrough medication was needed during the maintenance phase of 1-23 months. Data were acquired by a pain diary on a weekly basis. RESULTS: With 75-300 mg of lamotrigine per day, the burning and shooting pain intensity was relieved by 33-100%. Most obviously, the attack frequency of the shooting pain was reduced by 80-100%. No adverse effects were observed. CONCLUSION: We conclude that lamotrigine may be beneficial in the treatment of neuralgia after nerve section following the failure of previous pharmacological or surgical attempts.