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

Abstract

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.

Hardware-free MPFL reconstruction in patients with recurrent patellofemoral instability is safe and effective

“…Nevertheless, more than two-thirds of the patients presenting recurrent patellar dislocations demonstrate two or more pathoanatomical predisposing factors, which may synergistically predispose them to joint instability [64][65][66]. The association of additional procedures is still debated and should be evaluated at an individual level [1,67]. Six of eight studies were case…”

The Influence of Surgical Realignment Procedures on Dynamic Patellar Tracking: A Dynamic Magnetic Resonance Imaging-Controlled Feasibility Study

“…With the development of algorithmic classification systems and a better understanding of the individual pathogeneses, surgical treatment of patellofemoral instabilities has become more precise [ 11 , 12 ]. Several clinical studies have outlined the effectiveness of procedures, such as trochleoplasty [ 42 , 43 ], torsional DFO [ 16 , 44 ], varizating DFO [ 26 , 45 ], or tibial tubercle transfer [ 14 , 46 , 47 ], in terms of redislocation rates, improvement of clinical scores, or return to activity.…”

“…This observation was confirmed by multiple biomechanical investigations that demonstrated direct alterations of patellar tracking when certain risk factors were present [ 6 , 7 , 8 , 9 , 10 ]. On the basis of these findings, modern surgical approaches are aimed at identifying and addressing all relevant pathologies in the affected knee [ 11 , 12 , 13 ]. In the recent literature, several clinical studies have examined the postoperative success of individualized patellofemoral surgery, and most of these studies reported improved patient-reported outcome measures (PROMs) and low redislocation rates [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ].…”

Current concepts in the treatment of first-time patella dislocation in children and adolescents

“…There is disagreement about what procedure is indicated after the index injury. 23 , 24 Surgery needs to be considered individually for every patient. However, given that 50% to 70% of the children with first acute patellar dislocation will resolve without a second dislocation, routine corrective operation will not be justified for all patients.…”