Clinical and Functional Outcome After Lateral Trochlear Lengthening Osteotomy Lateral Trochlear Lengthening Osteotomy

Completed

• Conditions: Patellar Instability

• Registration Number: NCT04378491
• Lead Sponsor: University Hospital, Basel, Switzerland

Brief Summary

The purpose of this study is to evaluate the functional and clinical outcome of this new lengthening osteotomy of the lateral trochlea in patients with patella instability, trochlear dysplasia Dejour type A or B, short lateral articular trochlea quantified by the lateral condyle index and presence of a lateral trochlear bump.

Detailed Description

A short lateral articular trochlea leads to failure in stabilizing the patella close to full Extension of the knee. To address this type of pathology, a trochlear lengthening osteotomy was described. To date only case reports describing the clinical outcome of this new osteotomy exist and information on functional outcome regarding muscle strength and electromyography (EMG) data is lacking. The purpose of this study is to evaluate the functional and clinical outcome of this new lengthening osteotomy of the lateral trochlea in patients with patella instability, trochlear dysplasia Dejour type A or B, short lateral articular trochlea quantified by the lateral condyle index and presence of a lateral trochlear bump.

Study Timeline

• Study Start: 2020-04-01
• Study First Submitted: 2020-04-29
• Study First Submitted QC: 2020-05-04
• Study First Posted: 2020-05-07
• Primary Completion: 2020-09-30
• Study Completion: 2020-09-30
• Status Verified: 2020-11
• Last Update Submitted: 2020-11-09
• Last Update Posted: 2020-11-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 6

Inclusion Criteria

• 2 years (as of September 2019) since conducting a lateral trochlear lengthening osteotomy

Exclusion Criteria

• Inability to provide informed consent
• Neurological disorders potentially affecting lower extremity muscle strength.
• Surgery involving the patellofemoral joint prior to the lateral trochlear lengthening osteotomy

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
(Change in) Lateral condyle index assessed by MRI of the knee	at Baseline	Lateral condyle index assessed by MRI of the knee (preoperative (always conducted) and in the cases where they are available postoperative MRIs). The lateral condyle index was designed to measure the lateral trochlea by comparing the anterior cartilaginous trochlea (a) and the posterior aspect (p) \[(a:p)× 100\].
presence of a recurrent patellar dislocation/ radiological reduction of the trochlear bump postoperative by plain radiograph of the knee/ lateral view	at Baseline	presence of a recurrent patellar dislocation postoperative by plain radiograph of the knee/ lateral view: * crossing sign: The sign is positive when the trochlear groove lies in same plane as anterior border of lateral condyle. It represents a flattened trochlear groove; * double contour sign: The sign is positive when the anterior border of lateral condyle lies anterior to anterior border of medial condyle. It represents a convex trochlear groove/hypoplastic medial condyle; * presence of a lateral trochlear bump prominence; * the patellar height will be evaluated according to Insall-Salvati method (normal between 0.8 and 1.2) and Caton Deschamps method (normal between 0.6 and 1.3)
presence of a recurrent patellar dislocation/ radiological reduction of the trochlear bump postoperative by Skyline patellar view	at Baseline	The trochlea form will be assessed, the existence of trochlear dysplasia will be confirmed and classified according to Dejour

Secondary Outcome Measures

Name	Time	Method
Kujala Anterior Knee Pain Scale (AKPS)	at Baseline	The Kujala AKPS is a 13-item screening instrument designed to assess patellofemoral pain in adolescents and young adults, with a variable ordinal response format. For example, a 'Limp' score would be scored as follows: none (5), slight/periodic (3), constant (0). Total scores range from 0 to 100.
Lysholm Knee Score	at Baseline	The Lysholm Knee Score consists of eight items that measure: pain (25 points), instability (25 points), locking (15 points), swelling (10 points), limp (5 points), stair climbing (10 points), squatting (5 points), and need for support (5 points). Every question response has been assigned an arbitrary score on an increasing scale. The total score is the sum of each response to the eight questions, and may range from 0-100. Higher scores indicate a better outcome with fewer symptoms or disability.
Tegner activity scale	at Baseline	The Tegner activity scale is a one-item score that graded activity based on work and sports activities on a scale of 0 to 10. Zero represents disability because of knee problems and 10 represents national or international level soccer.
Visual analog scale score (VAS)	at Baseline	The visual analogue scale (VAS) is a 100-mm horizontal line on which the patient's pain intensity is represented by a point between the extremes of "no pain at all" and "worst pain imaginable.
Subjective Evaluation of the outcome of the operation	at Baseline	The patients will be asked to subjectively evaluate the outcome of the operation according to the following options: * Excellent: Patient is fully recovered and has resumed all activity without restrictions; * Somewhat Improved: Patient is mostly recovered and has resumed a majority of activities; * Unchanged: Patient outcome is equivalent to pre-operative complaints; * Somewhat Worse: Patient is experiencing symptoms worse than pre-operative complaints; * Significantly Worse: Patient outcome is worse than pre-operative complaints with significantly worse symptoms

Trial Locations

Locations (1)

Orthopädie/Traumatologie, University Hospital Basel; 🇨🇭 Basel, Switzerland